/* ========== Reset ========== */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

    ::selection {
      background: rgba(206,0,0,0.15);
      color: var(--color-text);
    }

    :root {
      /* bullstory brand color palette */
      --color-bg: #fbfbfd;
      --color-surface: #ffffff;
      --color-surface-elevated: rgba(255,255,255,0.82);
      --color-text: #1d1d1f;
      --color-text-secondary: #6e6e73;
      --color-text-tertiary: #86868b;
      --color-primary: #CE0000;
      --color-primary-hover: #B80000;
      --color-primary-text-sm: #A80000; /* #CE0000 darker variant for small text (≤12px) — WCAG AA 7:1+ contrast on white */
      --color-primary-bg: rgba(206,0,0,0.06);
      --color-accent: #1d1d1f;
      --color-border: rgba(0,0,0,0.06);
      --color-border-strong: rgba(0,0,0,0.1);
      --color-border-glass: rgba(255,255,255,0.5);
      --color-sale: #bf4800;
      --color-success: #248a3d;
      --color-info: #007aff;

      --radius-xl: 24px;
      --radius-lg: 20px;
      --radius-md: 14px;
      --radius-sm: 10px;
      --radius-xs: 6px;
      --radius-pill: 999px;

      --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 24px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 36px rgba(0,0,0,0.1), 0 2px 8px rgba(0,0,0,0.04);
      --shadow-elevated: 0 20px 60px rgba(0,0,0,0.12), 0 8px 20px rgba(0,0,0,0.06);

      --font-en: 'Pretendard Variable', Pretendard, -apple-system, BlinkMacSystemFont, sans-serif;
      --font-kr: 'Pretendard Variable', Pretendard, -apple-system, BlinkMacSystemFont, sans-serif;
      --font: var(--font-kr);

      --page-max: 1080px;
      --page-pad: 24px;

      --sp-xs: 4px;
      --sp-sm: 8px;
      --sp-md: 12px;
      --sp-lg: 16px;
      --sp-xl: 20px;
      --sp-2xl: 24px;
      --sp-3xl: 32px;
      --sp-4xl: 40px;
      --sp-5xl: 48px;
      --sp-6xl: 64px;
      --sp-7xl: 80px;
      --sp-8xl: 100px;
      --sp-9xl: 120px;

      /* ===== Motion System (Apple-grade organic) ===== */
      --ease-out-quint: cubic-bezier(0.22, 1, 0.36, 1);
      --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
      --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
      --ease-spring-soft: cubic-bezier(0.175, 0.885, 0.32, 1.275);
      --ease-in-out-quart: cubic-bezier(0.76, 0, 0.24, 1);
      --ease-in-cubic: cubic-bezier(0.55, 0, 1, 0.45);

      --dur-micro: 120ms;
      --dur-fast: 200ms;
      --dur-normal: 350ms;
      --dur-slow: 500ms;
      --dur-reveal: 0.7s;
      --dur-dramatic: 0.9s;
      --stagger-gap: 0.07s;
    }

    /* ========== Dark Mode ========== */
    [data-theme="dark"] {
      --color-bg: #1a1a1a;
      --color-surface: #2a2a2a;
      --color-surface-elevated: rgba(42,42,42,0.82);
      --color-text: #f5f5f5;
      --color-text-secondary: #a0a0a0;
      --color-text-tertiary: #666666;
      --color-primary: #FF3333;
      --color-primary-hover: #FF4D4D;
      --color-primary-text-sm: #FF4D4D;
      --color-primary-bg: rgba(255,51,51,0.1);
      --color-accent: #f5f5f5;
      --color-border: rgba(255,255,255,0.08);
      --color-border-strong: rgba(255,255,255,0.15);
      --color-border-glass: rgba(255,255,255,0.1);
      --color-sale: #FF6B35;
      --color-success: #34C759;

      --shadow-card: 0 2px 8px rgba(0,0,0,0.2), 0 0 1px rgba(0,0,0,0.3);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.3);
      --shadow-elevated: 0 20px 60px rgba(0,0,0,0.4);

      color-scheme: dark;
    }

    [data-theme="dark"] ::selection {
      background: rgba(255,51,51,0.25);
    }

    [data-theme="dark"] .header {
      background: rgba(26,26,26,0.85);
    }

    [data-theme="dark"] .header-search input {
      background: rgba(255,255,255,0.08);
    }

    [data-theme="dark"] .header-search input:focus {
      background: rgba(255,255,255,0.12);
      box-shadow: 0 0 0 3px rgba(255,51,51,0.15);
    }

    [data-theme="dark"] .category-bar {
      background: rgba(255,255,255,0.06);
    }

    [data-theme="dark"] .category-tag.active {
      background: var(--color-surface);
    }

    [data-theme="dark"] .book-card-cover {
      background: #222;
    }

    [data-theme="dark"] .detail-cover {
      background: linear-gradient(160deg, #222 0%, #1a1a1a 100%);
    }

    [data-theme="dark"] .detail-price-section {
      background: rgba(255,255,255,0.04);
    }

    [data-theme="dark"] .modal-overlay {
      background: rgba(0,0,0,0.55);
    }

    [data-theme="dark"] .btn-google {
      background: var(--color-surface);
      border-color: rgba(255,255,255,0.15);
    }

    [data-theme="dark"] .btn-google:hover {
      background: rgba(255,255,255,0.08);
      border-color: rgba(255,255,255,0.25);
    }

    [data-theme="dark"] .nav-link:hover {
      background: rgba(255,255,255,0.06);
    }

    [data-theme="dark"] .mobile-menu-btn:hover {
      background: rgba(255,255,255,0.06);
    }

    [data-theme="dark"] .mobile-nav-drawer {
      background: #1e1e1e;
    }

    [data-theme="dark"] .mobile-nav-overlay {
      background: rgba(0,0,0,0.5);
    }

    [data-theme="dark"] .mobile-nav-link:hover {
      background: rgba(255,255,255,0.06);
    }

    [data-theme="dark"] .mobile-nav-search input {
      background: rgba(255,255,255,0.08);
    }

    [data-theme="dark"] .mobile-nav-search input:focus {
      background: rgba(255,255,255,0.12);
      box-shadow: 0 0 0 3px rgba(255,51,51,0.15);
    }

    [data-theme="dark"] .mobile-nav-close:hover {
      background: rgba(255,255,255,0.08);
    }

    [data-theme="dark"] .modal-close:hover {
      background: rgba(255,255,255,0.08);
    }

    [data-theme="dark"] .toast {
      background: rgba(245,245,245,0.95);
      color: #1a1a1a;
    }

    [data-theme="dark"] .toast.error {
      background: #ff3b30;
      color: #fff;
    }

    [data-theme="dark"] .toast.success {
      background: var(--color-success);
      color: #fff;
    }

    [data-theme="dark"] .scroll-top-btn {
      background: rgba(42,42,42,0.85);
      color: var(--color-text);
      box-shadow: 0 2px 12px rgba(0,0,0,0.3), 0 0 0 0.5px rgba(255,255,255,0.08);
    }

    [data-theme="dark"] .scroll-top-btn:hover {
      background: rgba(50,50,50,0.95);
      box-shadow: 0 6px 20px rgba(0,0,0,0.4), 0 0 1px rgba(255,255,255,0.1);
    }

    [data-theme="dark"] .purchase-item:hover {
      background: rgba(255,255,255,0.03);
    }

    [data-theme="dark"] .purchase-item-cover {
      background: #222;
    }

    [data-theme="dark"] .skeleton-cover,
    [data-theme="dark"] .skeleton-line,
    [data-theme="dark"] .skeleton-detail-cover,
    [data-theme="dark"] .skeleton-purchase-cover {
      background: linear-gradient(90deg, #2a2a2a 25%, #333 50%, #2a2a2a 75%);
      background-size: 200% 100%;
    }

    [data-theme="dark"] :focus-visible {
      outline-color: rgba(255,51,51,0.5);
    }

    /* -- 에디터 프로필 다크모드 -- */
    [data-theme="dark"] .editor-avatar {
      background: linear-gradient(135deg, rgba(255,51,51,0.12) 0%, rgba(255,51,51,0.06) 100%);
      box-shadow: 0 2px 12px rgba(255,51,51,0.1);
    }

    [data-theme="dark"] .editor-stat {
      background: rgba(255,255,255,0.04);
      border-color: rgba(255,255,255,0.08);
    }

    /* -- 쿠폰 캡슐 드롭다운 다크모드 -- */
    [data-theme="dark"] .coupon-capsule-dropdown {
      background: #2a2a2a;
      border-color: rgba(255,255,255,0.1);
      box-shadow: 0 12px 40px rgba(0,0,0,0.4);
    }

    [data-theme="dark"] .coupon-dropdown-item:hover {
      background: rgba(255,51,51,0.08);
    }

    [data-theme="dark"] .coupon-claim-section {
      background: rgba(255,255,255,0.03);
      border-color: rgba(255,255,255,0.08);
    }

    [data-theme="dark"] .coupon-claim-input {
      background: rgba(255,255,255,0.06);
      border-color: rgba(255,255,255,0.1);
    }

    /* ========== Theme Toggle Button ========== */
    .theme-toggle {
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      transition: background 0.2s, transform 0.2s;
      flex-shrink: 0;
      color: var(--color-text-secondary);
    }

    .theme-toggle:hover {
      background: rgba(0,0,0,0.06);
      color: var(--color-text);
    }

    [data-theme="dark"] .theme-toggle:hover {
      background: rgba(255,255,255,0.08);
    }

    .theme-toggle:active {
      transform: scale(0.9);
    }

    .theme-toggle svg {
      width: 18px;
      height: 18px;
      transition: transform var(--dur-normal) var(--ease-spring-soft);
    }

    .theme-toggle:hover svg {
      transform: rotate(20deg) scale(1.1);
    }

    .theme-toggle .icon-sun,
    .theme-toggle .icon-moon { display: none; }

    /* 라이트 모드: 달 아이콘 표시 (다크로 전환 의미) */
    .theme-toggle .icon-moon { display: block; }
    .theme-toggle .icon-sun { display: none; }

    [data-theme="dark"] .theme-toggle .icon-moon { display: none; }
    [data-theme="dark"] .theme-toggle .icon-sun { display: block; }

    html { scroll-behavior: smooth; color-scheme: light; }
    [data-theme="dark"] { color-scheme: dark; }

    body {
      font-family: var(--font);
      background: var(--color-bg);
      color: var(--color-text);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      text-rendering: optimizeLegibility;
      font-feature-settings: 'kern' 1;
    }

    /* 노이즈 텍스처 제거 — 미니멀 디자인 */

    a { color: inherit; text-decoration: none; }
    button { font-family: inherit; cursor: pointer; border: none; background: none; }
    img { display: block; max-width: 100%; }

    .container {
      max-width: var(--page-max);
      margin: 0 auto;
      padding: 0 var(--page-pad);
    }

    /* ========== Scroll Reveal Animation System (data-anim) ========== */
    /* 애플급 유기적 애니메이션 — 생물적 모션, spring-damped easing + stagger */
    [data-anim] {
      opacity: 0;
      will-change: transform, opacity;
      transition-property: opacity, transform, filter;
      transition-duration: var(--dur-reveal);
      transition-timing-function: var(--ease-out-quint);
      transition-delay: var(--anim-delay, 0s);
    }

    [data-anim].is-visible {
      opacity: 1;
      transform: none;
      filter: none;
    }

    /* --- 애니메이션 유형별 초기 상태 --- */
    [data-anim="fade-up"] {
      transform: translateY(28px) scale(0.98);
    }

    [data-anim="fade-down"] {
      transform: translateY(-20px) scale(0.98);
    }

    [data-anim="fade-left"] {
      transform: translateX(-28px) scale(0.98);
    }

    [data-anim="fade-right"] {
      transform: translateX(28px) scale(0.98);
    }

    [data-anim="fade-scale"] {
      transform: scale(0.90);
    }

    [data-anim="fade-blur"] {
      transform: translateY(16px) scale(0.97);
      filter: blur(8px);
    }

    [data-anim="fade"] {
      /* opacity만 (transform 없음) */
    }

    /* --- 신규 변형: 히어로 드라마틱 reveal --- */
    [data-anim="hero-reveal"] {
      transform: translateY(48px) scale(0.95);
      filter: blur(4px);
      transition-duration: var(--dur-dramatic);
    }

    /* --- 신규 변형: 카드 rise (3D-like) --- */
    [data-anim="card-rise"] {
      transform: translateY(24px) scale(0.96);
      filter: blur(2px);
    }

    /* --- 카드 stagger 최적화 (그리드 내 자식 순차 노출) --- */
    [data-anim-stagger] > [data-anim]:nth-child(1)  { --anim-delay: 0s; }
    [data-anim-stagger] > [data-anim]:nth-child(2)  { --anim-delay: 0.05s; }
    [data-anim-stagger] > [data-anim]:nth-child(3)  { --anim-delay: 0.10s; }
    [data-anim-stagger] > [data-anim]:nth-child(4)  { --anim-delay: 0.15s; }
    [data-anim-stagger] > [data-anim]:nth-child(5)  { --anim-delay: 0.20s; }
    [data-anim-stagger] > [data-anim]:nth-child(6)  { --anim-delay: 0.25s; }
    [data-anim-stagger] > [data-anim]:nth-child(7)  { --anim-delay: 0.30s; }
    [data-anim-stagger] > [data-anim]:nth-child(8)  { --anim-delay: 0.35s; }
    [data-anim-stagger] > [data-anim]:nth-child(9)  { --anim-delay: 0.40s; }
    [data-anim-stagger] > [data-anim]:nth-child(10) { --anim-delay: 0.45s; }
    [data-anim-stagger] > [data-anim]:nth-child(11) { --anim-delay: 0.50s; }
    [data-anim-stagger] > [data-anim]:nth-child(12) { --anim-delay: 0.55s; }

    /* --- 히어로 오케스트레이션: 100ms stagger 간격 (h1→p→button 순차 등장) --- */
    .hero[data-anim-stagger] > [data-anim]:nth-child(1) { --anim-delay: 0s; }
    .hero[data-anim-stagger] > [data-anim]:nth-child(2) { --anim-delay: 0.1s; }
    .hero[data-anim-stagger] > [data-anim]:nth-child(3) { --anim-delay: 0.2s; }

    /* 레거시 fade-in 호환 (JS 동적 요소용 폴백) */
    .fade-in {
      opacity: 0;
      transform: translateY(12px);
      transition: opacity var(--dur-slow) var(--ease-out-quint),
                  transform var(--dur-slow) var(--ease-out-quint);
    }

    .fade-in.visible {
      opacity: 1;
      transform: translateY(0);
    }

    /* ========== Header (Apple-style glassmorphism) ========== */
    .header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(251,251,253,0.78);
      backdrop-filter: saturate(200%) blur(24px);
      -webkit-backdrop-filter: saturate(200%) blur(24px);
    }

    .header-inner {
      display: flex;
      align-items: center;
      height: 52px;
      gap: var(--sp-lg);
    }

    .logo {
      font-family: var(--font-en);
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.2em;
      color: var(--color-text);
      flex-shrink: 0;
      transition: opacity 0.2s;
      text-transform: uppercase;
    }

    .logo:hover { opacity: 0.7; }

    .logo .accent {
      color: var(--color-primary);
    }

    .header-nav {
      display: flex;
      align-items: center;
      gap: 2px;
      flex: 1;
      min-width: 0;
    }

    .nav-link--main {
      font-size: 13.5px;
      font-weight: 500;
    }
    .nav-link--main.active {
      color: var(--color-text);
      font-weight: 700;
    }

    /* nav 안의 구분선 — 이 뒤로는 우측 정렬 */
    .nav-divider {
      width: 1px;
      height: 16px;
      background: var(--color-border-strong);
      margin: 0 var(--sp-sm) 0 auto;
    }

    .mobile-nav-divider {
      height: 1px;
      background: var(--color-border-strong);
      margin: var(--sp-md) 0;
    }

    .nav-link {
      padding: var(--sp-sm) var(--sp-md);
      font-size: 13px;
      font-weight: 500;
      color: var(--color-text-secondary);
      border-radius: var(--radius-pill);
      transition: color 0.2s, background 0.2s;
      letter-spacing: -0.1px;
    }

    .nav-link:hover {
      color: var(--color-text);
      background: rgba(0,0,0,0.03);
    }

    .nav-link.active {
      color: var(--color-text);
      font-weight: 600;
    }

    .nav-link.cta {
      color: var(--color-primary);
      font-weight: 600;
    }

    .nav-link.cta:hover {
      background: var(--color-primary-bg);
    }

    .nav-user {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
    }

    .nav-avatar {
      width: 28px;
      height: 28px;
      border-radius: 50%;
      overflow: hidden;
      background: var(--color-border);
    }

    .nav-avatar img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .nav-username {
      font-size: 13px;
      font-weight: 500;
      color: var(--color-text);
    }

    /* ========== Search Bar ========== */
    .header-search {
      flex: 0 1 220px;
      min-width: 140px;
      max-width: 240px;
      position: relative;
    }

    .header-search input {
      width: 100%;
      height: 34px;
      padding: 0 var(--sp-lg) 0 34px;
      border: none;
      border-radius: var(--radius-pill);
      font-size: 13px;
      font-family: var(--font);
      background: rgba(0,0,0,0.04);
      color: var(--color-text);
      outline: none;
      transition: background 0.2s, box-shadow 0.3s;
    }

    .header-search input::placeholder {
      color: var(--color-text-tertiary);
    }

    .header-search input:focus {
      background: rgba(0,0,0,0.06);
      box-shadow: 0 0 0 3px rgba(206,0,0,0.1);
    }

    .header-search .search-icon {
      position: absolute;
      left: var(--sp-md);
      top: 50%;
      transform: translateY(-50%);
      width: 14px;
      height: 14px;
      color: var(--color-text-tertiary);
    }

    .header-search .search-icon svg {
      width: 100%;
      height: 100%;
    }

    /* ========== Views ========== */
    .view { display: none; }
    .view.active {
      display: block;
      animation: viewFadeIn var(--dur-slow) var(--ease-out-quint) both;
    }

    @keyframes viewFadeIn {
      from { opacity: 0; transform: translateY(12px) scale(0.99); }
      to   { opacity: 1; transform: translateY(0) scale(1); }
    }

    @keyframes dropdownFadeIn {
      from { opacity: 0; transform: translateY(-6px) scale(0.97); }
      to   { opacity: 1; transform: translateY(0) scale(1); }
    }

    /* 뷰 내부 자식 순차 노출 (data-anim + 레거시 fade-in 호환) */
    .view.active > [data-anim]:nth-child(1),
    .view.active > .fade-in:nth-child(1) { --anim-delay: 0s; transition-delay: 0s; }
    .view.active > [data-anim]:nth-child(2),
    .view.active > .fade-in:nth-child(2) { --anim-delay: 0.06s; transition-delay: 0.06s; }
    .view.active > [data-anim]:nth-child(3),
    .view.active > .fade-in:nth-child(3) { --anim-delay: 0.12s; transition-delay: 0.12s; }
    .view.active > [data-anim]:nth-child(4),
    .view.active > .fade-in:nth-child(4) { --anim-delay: 0.18s; transition-delay: 0.18s; }

    /* ========== Hero Section (왼쪽 정렬 미니멀) ========== */
    .hero {
      padding: var(--sp-3xl) 0 var(--sp-lg);
      text-align: left;
      position: relative;
      overflow: hidden;
    }

    .hero-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-sm);
      font-size: 12px;
      font-weight: 600;
      color: var(--color-primary-text-sm);
      margin-bottom: var(--sp-2xl);
      letter-spacing: 1.5px;
      text-transform: uppercase;
      font-family: var(--font-en);
      padding: var(--sp-sm) var(--sp-lg);
      background: var(--color-primary-bg);
      border-radius: var(--radius-pill);
    }

    .hero h1 {
      font-size: 36px;
      font-weight: 700;
      letter-spacing: -1.6px;
      line-height: 1.25;
      margin-bottom: var(--sp-md);
      color: var(--color-text);
      max-width: 720px;
    }

    .hero p {
      font-size: 15px;
      font-weight: 400;
      color: var(--color-text-secondary);
      line-height: 1.6;
      letter-spacing: -0.3px;
      max-width: 640px;
      margin: 0;
    }

    .hero-cta {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-sm);
      margin-top: var(--sp-4xl);
      padding: var(--sp-lg) var(--sp-3xl);
      font-size: 16px;
      font-weight: 600;
      color: #fff;
      background: var(--color-primary);
      border-radius: var(--radius-pill);
      transition: transform var(--dur-normal) var(--ease-spring-soft),
                  background var(--dur-fast) ease,
                  box-shadow var(--dur-normal) var(--ease-out-quint);
      letter-spacing: -0.2px;
      will-change: transform;
      animation: ctaBreathe 3.5s var(--ease-in-out-quart) 1.5s infinite;
    }

    .hero-cta:hover {
      background: var(--color-primary-hover);
      transform: scale(1.04) translateY(-1px);
      box-shadow: 0 8px 24px rgba(206, 0, 0, 0.25);
      animation: none;
    }

    .hero-cta:active {
      transform: scale(0.96);
      transition-duration: var(--dur-micro);
      animation: none;
    }

    .hero-cta svg {
      width: 16px;
      height: 16px;
      transition: transform var(--dur-normal) var(--ease-out-quint);
    }

    .hero-cta:hover svg {
      animation: ctaArrowFloat 1.5s var(--ease-out-quint) infinite;
    }

    @keyframes ctaArrowFloat {
      0%, 100% { transform: translateY(0); }
      50% { transform: translateY(4px); }
    }

    /* CTA 숨쉬기 — 미세 글로우 펄스 (생물적 존재감) */
    @keyframes ctaBreathe {
      0%, 100% { box-shadow: 0 4px 14px rgba(206, 0, 0, 0.12); }
      50% { box-shadow: 0 8px 32px rgba(206, 0, 0, 0.3); }
    }

    /* 범용 글로우 펄스 (인터랙티브 요소에 적용 가능) */
    @keyframes pulseGlow {
      0%, 100% { box-shadow: 0 0 0 0 rgba(206, 0, 0, 0); }
      50% { box-shadow: 0 0 20px 4px rgba(206, 0, 0, 0.15); }
    }

    /* 스크롤 힌트 바운스 (히어로 하단 안내 화살표용) */
    @keyframes scrollHint {
      0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
      40% { transform: translateY(6px); }
      60% { transform: translateY(3px); }
    }

    /* ========== Category Filter ========== */
    .category-section {
      padding-bottom: var(--sp-5xl);
    }

    .category-bar {
      display: flex;
      gap: var(--sp-xs);
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: none;
      padding: var(--sp-xs);
      background: rgba(0,0,0,0.04);
      border-radius: var(--radius-pill);
      width: fit-content;
    }

    .category-bar::-webkit-scrollbar { display: none; }

    .category-tag {
      padding: var(--sp-sm) var(--sp-xl);
      font-size: 13px;
      font-weight: 500;
      white-space: nowrap;
      border-radius: var(--radius-pill);
      background: transparent;
      color: var(--color-text-secondary);
      transition: color var(--dur-fast) ease,
                  background var(--dur-fast) ease,
                  transform var(--dur-micro) var(--ease-spring);
    }

    .category-tag:hover {
      color: var(--color-text);
    }

    .category-tag:active {
      transform: scale(0.95);
    }

    .category-tag.active {
      background: var(--color-surface);
      color: var(--color-text);
      font-weight: 600;
    }

    /* ========== Book Grid (Apple Books 스타일) ========== */
    /* 모바일 2열 / 1024px 3열 / 1440px 4열 */
    .book-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: var(--sp-2xl) var(--sp-xl);
    }
    @media (min-width: 768px) {
      .book-grid { grid-template-columns: repeat(3, 1fr); }
    }
    @media (min-width: 1280px) {
      .book-grid { grid-template-columns: repeat(4, 1fr); }
    }

    /* 카드 자체는 컨테이너만 — 표지 + 외부 텍스트로 구성 */
    .book-card {
      background: transparent;
      border-radius: 0;
      overflow: visible;
      cursor: pointer;
      transition: transform var(--dur-normal) var(--ease-spring-soft);
      will-change: transform;
    }

    .book-card:hover {
      transform: translateY(-4px);
    }

    .book-card:active {
      transform: translateY(0) scale(0.98);
      transition-duration: var(--dur-micro);
    }

    /* 카드 = 표지. 둥근 모서리 + 그림자 + 광택 */
    .book-card-cover {
      position: relative;
      width: 100%;
      aspect-ratio: 3/4;
      background: var(--cover-color, #f2f2f5);
      overflow: hidden;
      border-radius: var(--radius-lg);
      box-shadow: 0 4px 16px rgba(0,0,0,0.10), 0 1px 3px rgba(0,0,0,0.06);
      transition: box-shadow var(--dur-normal) var(--ease-out-quint);
    }

    .book-card:hover .book-card-cover {
      box-shadow: 0 12px 32px rgba(0,0,0,0.16), 0 2px 8px rgba(0,0,0,0.08);
    }

    /* 가로형(report): 4:3 비율 */
    .book-card.is-landscape .book-card-cover {
      aspect-ratio: 4/3;
    }

    [data-theme="dark"] .book-card-cover {
      box-shadow: 0 4px 16px rgba(0,0,0,0.5), 0 0 0 1px rgba(255,255,255,0.05);
    }

    .book-card-cover img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform var(--dur-slow) var(--ease-out-quint);
    }

    .book-card:hover .book-card-cover img {
      transform: scale(1.04);
    }

    /* 형식 배지 (우상단 글래스모피즘) */
    .book-card-type-badge {
      position: absolute;
      top: var(--sp-sm);
      right: var(--sp-sm);
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 4px var(--sp-sm);
      font-size: 10.5px;
      font-weight: 600;
      letter-spacing: -0.1px;
      color: rgba(255,255,255,0.95);
      background: rgba(0,0,0,0.42);
      backdrop-filter: blur(10px) saturate(180%);
      -webkit-backdrop-filter: blur(10px) saturate(180%);
      border-radius: var(--radius-pill);
      border: 1px solid rgba(255,255,255,0.15);
      pointer-events: none;
    }
    .book-card-type-badge .type-icon {
      font-size: 11px;
      line-height: 1;
    }
    .book-card-type-badge--ebook  { background: rgba(46,68,120,0.55); }
    .book-card-type-badge--report { background: rgba(186,84,40,0.55); }
    .book-card-type-badge--post   { background: rgba(40,128,80,0.55); }
    .book-card-type-badge--course { background: rgba(110,60,130,0.55); }

    /* 카드 외부 텍스트 영역 */
    .book-card-outside {
      padding: var(--sp-md) 4px 0;
    }

    .book-card-out-title {
      font-size: 14px;
      font-weight: 600;
      line-height: 1.35;
      letter-spacing: -0.3px;
      color: var(--color-text);
      margin-bottom: 2px;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    .book-card-out-author {
      font-size: 12.5px;
      color: var(--color-text-tertiary);
      margin-bottom: var(--sp-xs);
      display: -webkit-box;
      -webkit-line-clamp: 1;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    .book-card-out-price-row {
      display: flex;
      align-items: baseline;
      gap: var(--sp-sm);
      flex-wrap: wrap;
    }

    .book-card-out-price {
      font-family: var(--font-en);
      font-size: 14px;
      font-weight: 700;
      color: var(--color-text);
      letter-spacing: -0.3px;
    }

    .book-card-out-price small {
      font-family: var(--font-kr);
      font-size: 11px;
      font-weight: 500;
      margin-left: 1px;
    }

    .book-card-out-original {
      font-size: 11.5px;
      color: var(--color-text-tertiary);
      text-decoration: line-through;
    }

    body.premium-mode .book-card-out-title {
      color: var(--premium-text);
    }
    body.premium-mode .book-card-out-author,
    body.premium-mode .book-card-out-original {
      color: var(--premium-text-tertiary);
    }
    body.premium-mode .book-card-out-price {
      color: var(--premium-gold-bright);
    }

    /* ========== 형식 필터 탭 ========== */
    .format-bar-wrap {
      padding: 0 0 var(--sp-lg);
    }
    .format-bar {
      display: flex;
      gap: var(--sp-xs);
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: none;
    }
    .format-bar::-webkit-scrollbar { display: none; }

    /* 카탈로그 섹션 헤더 (전자책 / 강의) */
    .catalog-section {
      margin-bottom: var(--sp-4xl);
    }
    .catalog-section:last-of-type {
      margin-bottom: var(--sp-6xl);
    }
    .catalog-section-header {
      display: flex;
      align-items: baseline;
      gap: var(--sp-md);
      margin-bottom: var(--sp-xl);
    }
    .catalog-section-title {
      font-size: 22px;
      font-weight: 700;
      letter-spacing: -0.8px;
      color: var(--color-text);
    }
    .catalog-section-count {
      font-size: 13px;
      color: var(--color-text-tertiary);
      font-weight: 500;
    }

    /* 강의 카드 그리드 — 가로형이므로 그리드 폭 조정 (3열 기본) */
    .course-grid {
      grid-template-columns: repeat(2, 1fr);
    }
    @media (min-width: 768px) {
      .course-grid { grid-template-columns: repeat(3, 1fr); }
    }
    @media (min-width: 1280px) {
      .course-grid { grid-template-columns: repeat(3, 1fr); }
    }

    .empty-state--soft {
      padding: var(--sp-5xl) var(--sp-2xl);
      background: rgba(0,0,0,0.02);
      border-radius: var(--radius-lg);
      grid-column: 1 / -1;
    }
    [data-theme="dark"] .empty-state--soft {
      background: rgba(255,255,255,0.03);
    }

    .format-tag {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 6px var(--sp-md);
      font-size: 12.5px;
      font-weight: 500;
      letter-spacing: -0.2px;
      color: var(--color-text-tertiary);
      background: transparent;
      border: 1px solid var(--color-border-strong);
      border-radius: var(--radius-pill);
      white-space: nowrap;
      cursor: pointer;
      transition: color var(--dur-fast) ease,
                  background var(--dur-fast) ease,
                  border-color var(--dur-fast) ease,
                  transform var(--dur-micro) var(--ease-spring);
    }

    .format-tag span {
      font-size: 12px;
      line-height: 1;
    }

    .format-tag:hover {
      color: var(--color-text);
      border-color: var(--color-text-tertiary);
    }

    .format-tag:active {
      transform: scale(0.95);
    }

    .format-tag.active {
      color: var(--color-bg);
      background: var(--color-text);
      border-color: var(--color-text);
      font-weight: 600;
    }

    body.premium-mode .format-tag {
      color: var(--premium-text-tertiary);
      border-color: var(--premium-border-strong);
    }
    body.premium-mode .format-tag:hover {
      color: var(--premium-text);
    }
    body.premium-mode .format-tag.active {
      background: var(--premium-gold);
      border-color: var(--premium-gold);
      color: #1a1305;
    }

    .book-card-badge {
      position: absolute;
      top: var(--sp-sm);
      left: var(--sp-sm);
      padding: 4px var(--sp-sm);
      font-size: 10.5px;
      font-weight: 700;
      font-family: var(--font-en);
      background: rgba(255,255,255,0.95);
      color: #1d1d1f;
      backdrop-filter: blur(8px) saturate(180%);
      -webkit-backdrop-filter: blur(8px) saturate(180%);
      border-radius: var(--radius-pill);
      letter-spacing: 0.6px;
      text-transform: uppercase;
      box-shadow: 0 2px 8px rgba(0,0,0,0.12);
    }

    .book-card-body {
      padding: var(--sp-xl);
    }

    .book-card-category {
      display: inline-block;
      font-size: 10px;
      font-weight: 600;
      color: var(--color-primary-text-sm);
      text-transform: uppercase;
      letter-spacing: 1px;
      margin-bottom: var(--sp-sm);
      font-family: var(--font-en);
      background: var(--color-primary-bg);
      padding: 2px var(--sp-sm);
      border-radius: var(--radius-pill);
    }

    .book-card-title {
      font-size: 16px;
      font-weight: 700;
      line-height: 1.35;
      margin-bottom: var(--sp-xs);
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
      letter-spacing: -0.4px;
    }

    .book-card-author {
      font-size: 13px;
      color: var(--color-text-tertiary);
      margin-bottom: var(--sp-sm);
    }

    .book-card-desc {
      font-size: 12.5px;
      line-height: 1.5;
      color: var(--color-text-secondary);
      letter-spacing: -0.2px;
      margin-bottom: var(--sp-md);
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    .book-card-meta {
      display: flex;
      gap: var(--sp-sm);
      font-size: 11px;
      color: var(--color-text-tertiary);
      font-family: var(--font-en);
      font-weight: 600;
      letter-spacing: 0.3px;
      margin-bottom: var(--sp-md);
    }

    .book-card-meta span {
      display: inline-flex;
      align-items: center;
      padding: 2px var(--sp-sm);
      background: rgba(0,0,0,0.04);
      border-radius: var(--radius-xs);
    }

    [data-theme="dark"] .book-card-meta span {
      background: rgba(255,255,255,0.06);
    }

    body.premium-mode .premium-book-grid .book-card-desc {
      color: var(--premium-text-secondary);
    }

    body.premium-mode .premium-book-grid .book-card-meta {
      color: var(--premium-text-tertiary);
    }

    body.premium-mode .premium-book-grid .book-card-meta span {
      background: rgba(212, 175, 95, 0.08);
      color: var(--premium-gold);
    }

    .book-card-footer {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .book-card-price {
      font-family: var(--font-en);
      font-size: 18px;
      font-weight: 800;
      color: var(--color-text);
      letter-spacing: -0.5px;
      transition: color var(--dur-normal) var(--ease-out-expo);
    }

    .book-card:hover .book-card-price {
      color: var(--color-primary);
    }

    .book-card-price .unit {
      font-family: var(--font-kr);
      font-size: 12px;
      font-weight: 500;
    }

    .book-card-price .original {
      font-size: 12px;
      color: var(--color-text-tertiary);
      text-decoration: line-through;
      font-weight: 400;
      margin-left: var(--sp-sm);
    }

    .book-card-cta {
      font-size: 12px;
      font-weight: 600;
      color: var(--color-primary-text-sm);
      display: flex;
      align-items: center;
      gap: 2px;
      opacity: 0;
      transform: translateX(-8px);
      transition: opacity var(--dur-normal) var(--ease-out-expo),
                  transform var(--dur-normal) var(--ease-spring-soft);
    }

    .book-card:hover .book-card-cta {
      opacity: 1;
      transform: translateX(0);
    }

    /* ========== Empty State ========== */
    .empty-state {
      text-align: center;
      padding: var(--sp-8xl) var(--sp-2xl);
      color: var(--color-text-secondary);
    }

    .empty-state .icon {
      font-size: 56px;
      margin-bottom: var(--sp-xl);
      opacity: 0.25;
    }

    .empty-state h3 {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: var(--sp-sm);
      color: var(--color-text);
      letter-spacing: -0.5px;
    }

    .empty-state p {
      font-size: 15px;
      color: var(--color-text-secondary);
    }

    /* ========== Detail View ========== */
    .detail-back {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-sm);
      padding: var(--sp-md) 0;
      font-size: 14px;
      font-weight: 500;
      color: var(--color-primary);
      margin-top: var(--sp-2xl);
      transition: opacity 0.2s;
    }

    .detail-back:hover { opacity: 0.7; }

    .detail-back svg {
      width: 16px;
      height: 16px;
    }

    .detail-layout {
      display: grid;
      grid-template-columns: 380px 1fr;
      gap: var(--sp-6xl);
      padding: var(--sp-4xl) 0 var(--sp-9xl);
      align-items: start;
    }

    .detail-cover {
      width: 100%;
      aspect-ratio: 3/4;
      border-radius: var(--radius-xl);
      overflow: hidden;
      background: linear-gradient(160deg, #f8f8fa 0%, #ededf0 100%);
      box-shadow: 0 24px 60px rgba(0,0,0,0.14), 0 4px 16px rgba(0,0,0,0.06);
      transition: box-shadow var(--dur-slow) var(--ease-out-quint),
                  transform var(--dur-slow) var(--ease-out-quint);
    }

    /* 가로형 (report PDF) 표지: 4:3 */
    .detail-cover.is-landscape {
      aspect-ratio: 4/3;
    }

    /* 상세 페이지 hero 영역: 표지 dominant color 그라데이션 — Apple Music 스타일 */
    .detail-layout {
      position: relative;
    }
    .detail-layout::before {
      content: '';
      position: absolute;
      top: -120px;
      left: -10%;
      right: -10%;
      height: 480px;
      pointer-events: none;
      z-index: -1;
      background: radial-gradient(
        ellipse 60% 80% at 30% 0%,
        color-mix(in srgb, var(--cover-color, #1d1d1f) 28%, transparent),
        transparent 70%
      );
      opacity: 0.7;
      transition: opacity var(--dur-slow) var(--ease-out-quint);
    }
    [data-theme="dark"] .detail-layout::before {
      opacity: 0.55;
    }
    body.premium-mode .detail-layout::before {
      background: radial-gradient(
        ellipse 60% 80% at 30% 0%,
        color-mix(in srgb, var(--cover-color, #d4af5f) 32%, transparent),
        transparent 70%
      );
      opacity: 0.6;
    }

    .detail-cover:hover {
      transform: translateY(-4px);
      box-shadow: 0 32px 72px rgba(0,0,0,0.18), 0 6px 20px rgba(0,0,0,0.08);
    }

    .detail-cover img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform var(--dur-reveal) var(--ease-out-quint);
    }

    .detail-cover:hover img {
      transform: scale(1.03);
    }

    .detail-info {
      position: sticky;
      top: 76px;
    }

    .detail-category {
      display: inline-block;
      font-size: 12px;
      font-weight: 600;
      color: var(--color-primary-text-sm);
      text-transform: uppercase;
      letter-spacing: 1px;
      margin-bottom: var(--sp-md);
      font-family: var(--font-en);
      background: var(--color-primary-bg);
      padding: var(--sp-xs) var(--sp-md);
      border-radius: var(--radius-pill);
    }

    .detail-info h1 {
      font-size: 42px;
      font-weight: 800;
      line-height: 1.1;
      letter-spacing: -2px;
      margin-bottom: var(--sp-md);
    }

    .detail-author {
      font-size: 17px;
      color: var(--color-text-secondary);
      margin-bottom: var(--sp-2xl);
    }

    .detail-rating {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
      font-size: 14px;
      color: var(--color-text-secondary);
      margin-bottom: var(--sp-3xl);
    }

    .detail-rating .star { color: #FF9500; }

    /* 한 줄 강조 카피 — "왜 사야 하는지" 핵심 메시지 */
    .detail-pitch {
      font-size: 19px;
      font-weight: 600;
      line-height: 1.5;
      color: var(--color-text);
      letter-spacing: -0.4px;
      padding: var(--sp-md) 0 var(--sp-xl);
      margin-bottom: var(--sp-xl);
      border-bottom: 1px solid var(--color-border);
    }

    .detail-desc {
      font-size: 15px;
      line-height: 1.75;
      color: var(--color-text-secondary);
      margin-bottom: var(--sp-4xl);
      white-space: pre-line;
      letter-spacing: -0.2px;
    }

    /* 면책 문구 — 상세 페이지 최하단 */
    .detail-disclaimer {
      margin-top: var(--sp-2xl);
      padding: var(--sp-md) var(--sp-lg);
      font-size: 11.5px;
      line-height: 1.6;
      color: var(--color-text-tertiary);
      letter-spacing: -0.1px;
      border-left: 2px solid var(--color-border-strong);
      background: rgba(0,0,0,0.02);
      border-radius: 0 var(--radius-xs) var(--radius-xs) 0;
    }

    [data-theme="dark"] .detail-disclaimer,
    body.premium-mode .detail-disclaimer {
      background: rgba(255,255,255,0.03);
    }

    .detail-price-section {
      padding: var(--sp-3xl);
      background: rgba(0,0,0,0.02);
      border-radius: var(--radius-lg);
      margin-bottom: var(--sp-xl);
    }

    .detail-price {
      font-family: var(--font-en);
      font-size: 44px;
      font-weight: 800;
      letter-spacing: -2px;
      margin-bottom: var(--sp-xs);
    }

    .detail-price .unit {
      font-family: var(--font-kr);
      font-size: 20px;
      font-weight: 600;
    }

    .detail-price .original {
      font-size: 18px;
      color: var(--color-text-tertiary);
      text-decoration: line-through;
      font-weight: 400;
      margin-left: var(--sp-md);
    }

    .detail-price-note {
      font-size: 13px;
      color: var(--color-text-tertiary);
      letter-spacing: -0.1px;
    }

    /* 쿠폰 캡슐 버튼 (상세 페이지) */
    /* 쿠폰 적용 배지 (도서 상세) */
    .coupon-applied-badge {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-xs);
      padding: var(--sp-sm) var(--sp-lg);
      font-size: 13px;
      font-weight: 600;
      color: var(--color-primary);
      background: var(--color-primary-bg);
      border-radius: var(--radius-pill);
      margin-bottom: var(--sp-md);
    }

    .coupon-badge-icon {
      font-size: 15px;
    }

    .coupon-badge-clear {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 20px;
      height: 20px;
      border: none;
      background: rgba(206,0,0,0.15);
      border-radius: 50%;
      color: var(--color-primary);
      font-size: 14px;
      cursor: pointer;
      margin-left: var(--sp-xs);
      transition: background 0.15s;
      line-height: 1;
    }

    .coupon-badge-clear:hover {
      background: rgba(206,0,0,0.25);
    }

    /* 쿠폰 캡슐 토글 — 단일 정의 (아래 2920행 블록에서 관리) */

    /* 쿠폰 코드 등록 (내 서재) */
    .coupon-claim-section {
      margin-bottom: var(--sp-xl);
      padding: var(--sp-xl);
      background: var(--color-surface);
      border: 1.5px solid var(--color-border-strong);
      border-radius: var(--radius-md);
    }

    .coupon-claim-row {
      display: flex;
      gap: var(--sp-sm);
    }

    .coupon-claim-input {
      flex: 1;
      padding: var(--sp-md) var(--sp-lg);
      font-size: 14px;
      font-weight: 500;
      border: 1.5px solid var(--color-border-strong);
      border-radius: var(--radius-sm);
      background: var(--color-bg);
      color: var(--color-text);
      letter-spacing: 1px;
      text-transform: uppercase;
      transition: border-color 0.2s;
    }

    .coupon-claim-input:focus {
      outline: none;
      border-color: var(--color-primary);
    }

    .coupon-claim-input::placeholder {
      color: var(--color-text-tertiary);
      letter-spacing: 0;
      text-transform: none;
    }

    .coupon-claim-btn {
      padding: var(--sp-md) var(--sp-2xl);
      font-size: 14px;
      font-weight: 600;
      color: #fff;
      background: var(--color-primary);
      border: none;
      border-radius: var(--radius-sm);
      cursor: pointer;
      white-space: nowrap;
      transition: background 0.2s;
    }

    .coupon-claim-btn:hover {
      background: var(--color-primary-hover);
    }

    .coupon-claim-btn:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }

    .coupon-claim-result {
      margin-top: var(--sp-sm);
      font-size: 13px;
      line-height: 1.4;
    }

    .coupon-result {
      margin-top: var(--sp-sm);
      font-size: 13px;
      line-height: 1.4;
    }

    .coupon-success {
      color: var(--color-success);
      font-weight: 600;
    }

    .coupon-error {
      color: #ff3b30;
    }

    .coupon-discount-detail {
      margin-top: var(--sp-xs);
      color: var(--color-text-secondary);
    }

    .coupon-discount-detail strong {
      color: var(--color-primary);
    }

    /* 쿠폰 지갑 카드 */
    .coupon-wallet-loading {
      text-align: center;
      padding: var(--sp-3xl) 0;
      color: var(--color-text-tertiary);
      font-size: 14px;
    }

    .coupon-wallet-card {
      display: flex;
      align-items: stretch;
      background: var(--color-surface);
      border: 1.5px solid var(--color-border-strong);
      border-radius: var(--radius-md);
      overflow: hidden;
      margin-bottom: var(--sp-md);
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.2s, border-color 0.2s;
    }

    .coupon-wallet-card:hover {
      box-shadow: var(--shadow-card);
      border-color: var(--color-primary);
    }

    .coupon-wallet-left {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: var(--sp-xs);
      padding: var(--sp-xl) var(--sp-2xl);
      background: var(--color-primary-bg);
      min-width: 120px;
      text-align: center;
    }

    .coupon-wallet-discount {
      font-size: 22px;
      font-weight: 800;
      color: var(--color-primary);
      line-height: 1.2;
      letter-spacing: -0.5px;
    }

    .coupon-wallet-type {
      font-size: 11px;
      font-weight: 600;
      color: var(--color-text-tertiary);
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .coupon-wallet-badge {
      display: inline-block;
      padding: 2px var(--sp-sm);
      font-size: 10px;
      font-weight: 700;
      border-radius: var(--radius-pill);
      margin-top: var(--sp-xs);
      line-height: 1.6;
    }

    .badge-welcome {
      background: rgba(52,199,89,0.12);
      color: var(--color-success);
    }

    .badge-first {
      background: rgba(206,0,0,0.08);
      color: var(--color-primary);
    }

    .badge-personal {
      background: rgba(0,122,255,0.1);
      color: var(--color-info);
    }

    .coupon-wallet-divider {
      width: 1px;
      background: repeating-linear-gradient(
        to bottom,
        var(--color-border-strong) 0,
        var(--color-border-strong) 4px,
        transparent 4px,
        transparent 8px
      );
      flex-shrink: 0;
    }

    .coupon-wallet-right {
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: center;
      gap: var(--sp-sm);
      padding: var(--sp-lg) var(--sp-xl);
      min-width: 0;
    }

    .coupon-wallet-code {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
    }

    .coupon-wallet-code code {
      font-size: 15px;
      font-weight: 700;
      color: var(--color-text);
      letter-spacing: 1.5px;
      font-family: 'SF Mono', 'Fira Code', monospace;
    }

    .coupon-copy-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 36px;
      height: 36px;
      border: 1px solid var(--color-border-strong);
      border-radius: var(--radius-xs);
      background: var(--color-surface);
      cursor: pointer;
      font-size: 14px;
      transition: background 0.15s, border-color 0.15s;
      flex-shrink: 0;
    }

    .coupon-copy-btn:hover {
      background: var(--color-primary-bg);
      border-color: var(--color-primary);
    }

    .coupon-wallet-info {
      display: flex;
      flex-wrap: wrap;
      gap: var(--sp-xs) var(--sp-md);
      font-size: 12px;
      color: var(--color-text-tertiary);
      line-height: 1.4;
    }

    .coupon-wallet-info span {
      white-space: nowrap;
    }

    /* 결제 완료 쿠폰 안내 */
    .payment-coupon-notice {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
      padding: var(--sp-md) var(--sp-lg);
      margin-top: var(--sp-lg);
      background: rgba(52,199,89,0.08);
      border: 1px solid rgba(52,199,89,0.2);
      border-radius: var(--radius-sm);
      font-size: 13px;
      font-weight: 500;
      color: var(--color-text);
      line-height: 1.5;
    }

    .payment-coupon-notice strong {
      color: var(--color-primary);
      font-weight: 700;
      letter-spacing: 0.5px;
    }

    .coupon-gift-icon {
      font-size: 18px;
      flex-shrink: 0;
    }

    .btn-purchase {
      width: 100%;
      padding: var(--sp-xl) var(--sp-2xl);
      font-size: 17px;
      font-weight: 600;
      color: #fff;
      background: var(--color-primary);
      border-radius: var(--radius-pill);
      transition: transform var(--dur-fast) var(--ease-spring-soft),
                  background var(--dur-fast) ease,
                  box-shadow var(--dur-normal) var(--ease-out-quint);
      letter-spacing: -0.2px;
      will-change: transform;
    }

    .btn-purchase:hover {
      background: var(--color-primary-hover);
      transform: scale(1.02) translateY(-1px);
      box-shadow: 0 8px 24px rgba(206,0,0,0.25);
    }

    .btn-purchase:active {
      transform: scale(0.96);
      transition-duration: var(--dur-micro);
    }

    .btn-purchase:disabled {
      background: var(--color-text-tertiary);
      cursor: not-allowed;
      box-shadow: none;
      transform: none;
    }

    .btn-purchase.purchased {
      background: var(--color-success);
    }

    .btn-purchase.purchased:hover {
      box-shadow: 0 6px 20px rgba(36,138,61,0.3);
    }

    .detail-meta {
      margin-top: var(--sp-3xl);
    }

    .detail-meta-row {
      display: flex;
      justify-content: space-between;
      font-size: 14px;
      padding: var(--sp-md) 0;
    }

    .detail-meta-row .label {
      color: var(--color-text-tertiary);
    }

    .detail-meta-row .value {
      font-weight: 500;
      color: var(--color-text);
    }

    /* ========== My Page ========== */
    .my-header {
      padding: var(--sp-6xl) 0 var(--sp-3xl);
    }

    .my-header h2 {
      font-size: 32px;
      font-weight: 800;
      letter-spacing: -1px;
    }

    .my-header p {
      font-size: 16px;
      color: var(--color-text-secondary);
      margin-top: var(--sp-sm);
    }

    .my-tabs {
      display: flex;
      gap: var(--sp-xs);
      margin-bottom: var(--sp-3xl);
    }

    .my-tab {
      padding: var(--sp-sm) var(--sp-xl);
      font-size: 14px;
      font-weight: 500;
      color: var(--color-text-secondary);
      border-radius: var(--radius-pill);
      transition: all 0.2s;
    }

    .my-tab:hover { color: var(--color-text); }

    .my-tab.active {
      background: var(--color-text);
      color: #fff;
      font-weight: 600;
    }

    .editor-banner {
      display: flex;
      align-items: center;
      gap: var(--sp-lg);
      padding: var(--sp-lg) var(--sp-xl);
      margin-bottom: var(--sp-2xl);
      background: var(--color-surface);
      border: 1.5px solid var(--color-border);
      border-radius: var(--radius-lg);
      text-decoration: none;
      color: var(--color-text);
      transition: border-color 0.2s, box-shadow 0.2s;
    }

    .editor-banner:hover {
      border-color: var(--color-accent);
      box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    }

    .editor-banner-icon {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      height: 40px;
      border-radius: var(--radius-md);
      background: var(--color-accent);
      color: #fff;
      flex-shrink: 0;
    }

    .editor-banner-text {
      display: flex;
      flex-direction: column;
      gap: var(--sp-xs);
      flex: 1;
      min-width: 0;
    }

    .editor-banner-text strong {
      font-size: 15px;
      font-weight: 700;
    }

    .editor-banner-text span {
      font-size: 13px;
      color: var(--color-text-secondary);
    }

    .editor-banner-arrow {
      flex-shrink: 0;
      color: var(--color-text-secondary);
      transition: transform 0.2s;
    }

    .editor-banner:hover .editor-banner-arrow {
      transform: translateX(3px);
    }

    .purchase-list {
      display: flex;
      flex-direction: column;
      gap: var(--sp-md);
      padding-bottom: var(--sp-8xl);
    }

    .purchase-item {
      display: flex;
      align-items: center;
      gap: var(--sp-xl);
      padding: var(--sp-xl);
      background: var(--color-surface);
      border-radius: var(--radius-lg);
      transition: background var(--dur-normal) var(--ease-out-quint),
                  transform var(--dur-normal) var(--ease-spring-soft),
                  box-shadow var(--dur-normal) var(--ease-out-quint);
    }

    .purchase-item:hover {
      background: rgba(0,0,0,0.01);
      transform: translateX(6px);
    }

    .purchase-item-cover {
      width: 72px;
      height: 54px;
      border-radius: var(--radius-sm);
      background: #f2f2f5;
      overflow: hidden;
      flex-shrink: 0;
    }

    .purchase-item-cover img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .purchase-item-info {
      flex: 1;
      min-width: 0;
    }

    .purchase-item-title {
      font-size: 15px;
      font-weight: 600;
      margin-bottom: var(--sp-xs);
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      letter-spacing: -0.3px;
    }

    .purchase-item-date {
      font-size: 13px;
      color: var(--color-text-tertiary);
    }

    .purchase-item-coupon {
      font-size: 12px;
      font-weight: 500;
      color: var(--color-primary-text-sm);
      margin-top: var(--sp-xs);
    }

    .btn-read {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-xs);
      padding: var(--sp-sm) var(--sp-xl);
      font-size: 13px;
      font-weight: 600;
      color: var(--color-primary-text-sm);
      background: var(--color-primary-bg);
      border-radius: var(--radius-pill);
      flex-shrink: 0;
      transition: background 0.2s;
      letter-spacing: -0.1px;
      cursor: pointer;
    }

    .btn-read:hover {
      background: rgba(206,0,0,0.12);
    }

    /* ========== Login Modal ========== */
    .modal-overlay {
      position: fixed;
      inset: 0;
      z-index: 200;
      background: rgba(0,0,0,0.35);
      backdrop-filter: blur(24px) saturate(180%);
      -webkit-backdrop-filter: blur(24px) saturate(180%);
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      visibility: hidden;
      transition: opacity var(--dur-normal) ease, visibility var(--dur-normal);
    }

    .modal-overlay.active {
      opacity: 1;
      visibility: visible;
    }

    .modal {
      background: var(--color-surface);
      border-radius: var(--radius-xl);
      padding: var(--sp-5xl);
      width: 90%;
      max-width: 380px;
      box-shadow: var(--shadow-elevated);
      text-align: center;
      position: relative;
      transform: scale(0.92) translateY(12px);
      opacity: 0;
      transition: transform var(--dur-fast) var(--ease-in-cubic),
                  opacity var(--dur-micro) ease-in;
    }

    .modal-overlay.active .modal {
      transform: scale(1) translateY(0);
      opacity: 1;
      transition: transform var(--dur-slow) var(--ease-spring),
                  opacity var(--dur-normal) ease-out;
    }

    .modal-close {
      position: absolute;
      top: var(--sp-lg);
      right: var(--sp-lg);
      width: 44px;
      height: 44px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 16px;
      color: var(--color-text-tertiary);
      border-radius: 50%;
      transition: background 0.2s, color 0.2s;
    }

    .modal-close:hover {
      background: rgba(0,0,0,0.06);
      color: var(--color-text);
    }

    .modal h2 {
      font-size: 24px;
      font-weight: 800;
      letter-spacing: -0.8px;
      margin-bottom: var(--sp-sm);
    }

    .modal p {
      font-size: 15px;
      color: var(--color-text-secondary);
      margin-bottom: var(--sp-3xl);
      line-height: 1.5;
    }

    .btn-google {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: var(--sp-md);
      width: 100%;
      padding: var(--sp-lg) var(--sp-xl);
      font-size: 15px;
      font-weight: 600;
      color: var(--color-text);
      background: var(--color-surface);
      border: 1px solid var(--color-border-strong);
      border-radius: var(--radius-pill);
      transition: transform var(--dur-fast) var(--ease-spring-soft),
                  background var(--dur-fast) ease,
                  border-color var(--dur-fast) ease,
                  box-shadow var(--dur-fast) ease;
    }

    .btn-google:hover {
      background: var(--color-bg);
      border-color: rgba(0,0,0,0.18);
      box-shadow: 0 4px 16px rgba(0,0,0,0.08);
      transform: translateY(-1px);
    }

    .btn-google:active {
      transform: scale(0.96);
      transition-duration: var(--dur-micro);
    }

    .btn-google svg {
      width: 18px;
      height: 18px;
    }

    .modal-note {
      margin-top: var(--sp-xl);
      font-size: 12px;
      color: var(--color-text-tertiary);
    }

    /* ========== Toast ========== */
    .toast-container {
      position: fixed;
      top: var(--sp-6xl);
      left: 50%;
      transform: translateX(-50%);
      z-index: 300;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: var(--sp-sm);
    }

    .toast {
      padding: var(--sp-md) var(--sp-2xl);
      background: rgba(29,29,31,0.9);
      color: #fff;
      font-size: 14px;
      font-weight: 500;
      border-radius: var(--radius-pill);
      box-shadow: var(--shadow-elevated);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      animation: toastIn var(--dur-slow) var(--ease-spring) both;
      letter-spacing: -0.2px;
      transition: opacity var(--dur-fast) var(--ease-in-cubic),
                  transform var(--dur-fast) var(--ease-in-cubic);
    }

    .toast.error {
      background: #ff3b30;
    }

    .toast.success {
      background: var(--color-success);
    }

    @keyframes toastIn {
      0%   { opacity: 0; transform: translateY(-24px) scale(0.85); }
      50%  { opacity: 1; transform: translateY(3px) scale(1.02); }
      75%  { transform: translateY(-1px) scale(0.99); }
      100% { opacity: 1; transform: translateY(0) scale(1); }
    }

    /* ========== Loading ========== */
    .spinner {
      display: inline-block;
      width: 20px;
      height: 20px;
      border: 2px solid rgba(255,255,255,0.3);
      border-top-color: #fff;
      border-radius: 50%;
      animation: spin 0.6s linear infinite;
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    .page-loading {
      text-align: center;
      padding: var(--sp-7xl) 0;
    }

    .page-loading .spinner {
      width: 28px;
      height: 28px;
      border-color: rgba(0,0,0,0.08);
      border-top-color: var(--color-primary);
    }

    /* ========== Skeleton Loading (Apple-style shimmer) ========== */
    @keyframes shimmer {
      0% { background-position: 200% 0; }
      100% { background-position: -200% 0; }
    }

    .skeleton-card {
      background: var(--color-surface);
      border-radius: var(--radius-xl);
      overflow: hidden;
    }

    .skeleton-cover {
      aspect-ratio: 3/4;
      background: linear-gradient(90deg, #f0f0f3 25%, #f5f5f7 50%, #f0f0f3 75%);
      background-size: 200% 100%;
      animation: shimmer 1.8s ease-in-out infinite;
    }

    .skeleton-body {
      padding: var(--sp-xl);
    }

    .skeleton-line {
      height: 12px;
      margin-bottom: var(--sp-sm);
      background: linear-gradient(90deg, #f0f0f3 25%, #f5f5f7 50%, #f0f0f3 75%);
      background-size: 200% 100%;
      animation: shimmer 1.8s ease-in-out infinite;
      border-radius: 6px;
    }

    .skeleton-line.w-40 { width: 40%; }
    .skeleton-line.w-60 { width: 60%; }
    .skeleton-line.w-80 { width: 80%; }
    .skeleton-line.h-lg { height: 18px; }
    .skeleton-line.h-xl { height: 24px; }

    .skeleton-detail-layout {
      display: grid;
      grid-template-columns: 380px 1fr;
      gap: var(--sp-6xl);
      padding: var(--sp-4xl) 0 var(--sp-9xl);
      align-items: start;
    }

    .skeleton-detail-cover {
      aspect-ratio: 3/4;
      border-radius: var(--radius-xl);
      background: linear-gradient(90deg, #f0f0f3 25%, #f5f5f7 50%, #f0f0f3 75%);
      background-size: 200% 100%;
      animation: shimmer 1.8s ease-in-out infinite;
    }

    .skeleton-purchase-item {
      display: flex;
      align-items: center;
      gap: var(--sp-xl);
      padding: var(--sp-xl);
      background: var(--color-surface);
      border-radius: var(--radius-lg);
    }

    .skeleton-purchase-cover {
      width: 72px;
      height: 54px;
      border-radius: var(--radius-sm);
      background: linear-gradient(90deg, #f0f0f3 25%, #f5f5f7 50%, #f0f0f3 75%);
      background-size: 200% 100%;
      animation: shimmer 1.8s ease-in-out infinite;
      flex-shrink: 0;
    }

    @media (max-width: 768px) {
      .skeleton-detail-layout {
        grid-template-columns: 1fr;
        gap: var(--sp-3xl);
      }
      .skeleton-detail-cover {
        max-width: 320px;
        margin: 0 auto;
      }
    }

    /* ========== Focus Ring (accessibility) ========== */
    :focus-visible {
      outline: 3px solid rgba(206,0,0,0.4);
      outline-offset: 2px;
      border-radius: var(--radius-sm);
    }

    button:focus-visible {
      outline: 3px solid rgba(206,0,0,0.4);
      outline-offset: 2px;
    }

    /* ========== Reduced Motion ========== */
    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
      }
      [data-anim] { opacity: 1; transform: none !important; filter: none !important; }
      .fade-in { opacity: 1; transform: none; }
      .hero { transform: none !important; opacity: 1 !important; }
      .modal { transform: none !important; opacity: 1 !important; }
      .modal-overlay.active .modal { transform: none !important; }
      .book-card, .purchase-item, .scroll-top-btn, .detail-cover {
        transform: none !important;
      }
      .toast { animation: none !important; }
      .hero-cta, .scroll-top-btn.visible {
        animation: none !important;
      }
    }

    /* ========== Theme Transition ========== */
    /* 테마 전환 시 부드러운 전체 트랜지션 (JS에서 .theme-transitioning 클래스 토글) */
    html.theme-transitioning,
    html.theme-transitioning *,
    html.theme-transitioning *::before,
    html.theme-transitioning *::after {
      transition: background-color var(--dur-slow) var(--ease-in-out-quart),
                  color var(--dur-slow) var(--ease-in-out-quart),
                  border-color var(--dur-normal) var(--ease-in-out-quart),
                  box-shadow var(--dur-slow) var(--ease-in-out-quart),
                  fill var(--dur-normal) var(--ease-in-out-quart),
                  stroke var(--dur-normal) var(--ease-in-out-quart) !important;
    }

    /* reduced-motion 시 테마 전환 트랜지션 제거 */
    @media (prefers-reduced-motion: reduce) {
      html.theme-transitioning,
      html.theme-transitioning *,
      html.theme-transitioning *::before,
      html.theme-transitioning *::after {
        transition: none !important;
      }
    }

    /* ========== Footer ========== */
    .footer {
      padding: var(--sp-4xl) 0 var(--sp-3xl);
      margin-top: var(--sp-3xl);
    }

    .footer-inner {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: var(--sp-lg);
    }

    .footer-top {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .footer-biz {
      font-size: 11px;
      color: var(--color-text-tertiary);
      line-height: 1.8;
      text-align: center;
    }

    .footer-sep {
      margin: 0 6px;
      opacity: 0.4;
    }

    .footer-br {
      display: none;
    }

    @media (max-width: 768px) {
      .footer-br { display: block; }
      .footer-biz { text-align: center; }
    }

    .footer-logo {
      font-family: var(--font-en);
      font-size: 13px;
      font-weight: 700;
      color: var(--color-text-tertiary);
      letter-spacing: -0.3px;
    }

    .footer-text {
      font-size: 11px;
      color: var(--color-text-tertiary);
    }

    .footer-links {
      display: flex;
      gap: var(--sp-lg);
    }

    .footer-links a {
      font-size: 11px;
      color: var(--color-text-tertiary);
      transition: color 0.2s;
    }

    .footer-links a:hover {
      color: var(--color-text-secondary);
    }

    /* ========== Table of Contents (collapsible) ========== */
    .detail-toc {
      margin-top: var(--sp-4xl);
      padding-top: var(--sp-3xl);
    }

    .detail-toc-toggle {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      padding: 0;
      font-size: 18px;
      font-weight: 700;
      letter-spacing: -0.4px;
      color: var(--color-text);
      cursor: pointer;
      text-align: left;
    }

    .detail-toc-toggle svg {
      width: 20px;
      height: 20px;
      color: var(--color-text-tertiary);
      transition: transform var(--dur-normal) var(--ease-spring-soft);
    }

    .detail-toc-toggle.open svg {
      transform: rotate(180deg);
    }

    .detail-toc-content {
      font-size: 15px;
      line-height: 1.8;
      color: var(--color-text-secondary);
      white-space: pre-line;
      max-height: 0;
      overflow: hidden;
      transition: max-height var(--dur-slow) var(--ease-out-quint),
                  margin var(--dur-normal) var(--ease-out-quint);
      margin-top: 0;
    }

    .detail-toc-content.open {
      max-height: 2000px;
      margin-top: var(--sp-xl);
    }

    /* ========== Mobile Menu ========== */
    .mobile-menu-btn {
      display: none;
      width: 44px;
      height: 44px;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-pill);
      transition: background 0.2s;
      flex-shrink: 0;
    }

    .mobile-menu-btn:hover {
      background: rgba(0,0,0,0.04);
    }

    .mobile-menu-btn svg {
      width: 20px;
      height: 20px;
      color: var(--color-text);
    }

    .mobile-nav-overlay {
      position: fixed;
      inset: 0;
      z-index: 150;
      background: rgba(0,0,0,0.3);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      opacity: 0;
      visibility: hidden;
      transition: opacity var(--dur-normal) ease, visibility var(--dur-normal);
    }

    .mobile-nav-overlay.active {
      opacity: 1;
      visibility: visible;
    }

    .mobile-nav-drawer {
      position: fixed;
      top: 0;
      right: 0;
      bottom: 0;
      z-index: 151;
      width: 280px;
      max-width: 85vw;
      background: var(--color-surface);
      box-shadow: var(--shadow-elevated);
      transform: translateX(100%);
      transition: transform var(--dur-normal) var(--ease-out-expo);
      display: flex;
      flex-direction: column;
      padding: var(--sp-2xl);
      padding-bottom: calc(var(--sp-2xl) + env(safe-area-inset-bottom, 0px));
      overflow-y: auto;
    }

    .mobile-nav-drawer.active {
      transform: translateX(0);
    }

    .mobile-nav-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: var(--sp-3xl);
    }

    .mobile-nav-header .logo {
      font-size: 12px;
    }

    .mobile-nav-close {
      width: 44px;
      height: 44px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      color: var(--color-text-tertiary);
      transition: background 0.2s, color 0.2s;
    }

    .mobile-nav-close:hover {
      background: rgba(0,0,0,0.06);
      color: var(--color-text);
    }

    .mobile-nav-links {
      display: flex;
      flex-direction: column;
      gap: var(--sp-xs);
    }

    .mobile-nav-link {
      padding: var(--sp-md) var(--sp-lg);
      font-size: 16px;
      font-weight: 500;
      color: var(--color-text);
      border-radius: var(--radius-pill);
      transition: background 0.2s;
      text-align: left;
    }

    .mobile-nav-link:hover {
      background: rgba(0,0,0,0.04);
    }

    .mobile-nav-link.cta {
      color: var(--color-primary);
      font-weight: 600;
    }

    .mobile-nav-user {
      display: flex;
      align-items: center;
      gap: var(--sp-md);
      padding: var(--sp-lg);
      margin-top: auto;
    }

    .mobile-nav-user .nav-avatar {
      width: 36px;
      height: 36px;
    }

    .mobile-nav-user-info {
      font-size: 14px;
      font-weight: 500;
      color: var(--color-text);
    }

    .mobile-nav-search {
      position: relative;
      margin-bottom: var(--sp-xl);
    }

    .mobile-nav-search input {
      width: 100%;
      height: 40px;
      padding: 0 var(--sp-lg) 0 36px;
      border: none;
      border-radius: var(--radius-pill);
      font-size: 14px;
      font-family: var(--font);
      background: rgba(0,0,0,0.04);
      color: var(--color-text);
      outline: none;
      transition: background 0.2s, box-shadow 0.3s;
    }

    .mobile-nav-search input::placeholder {
      color: var(--color-text-tertiary);
    }

    .mobile-nav-search input:focus {
      background: rgba(0,0,0,0.06);
      box-shadow: 0 0 0 3px rgba(206,0,0,0.12);
    }

    .mobile-nav-search .search-icon {
      position: absolute;
      left: var(--sp-md);
      top: 50%;
      transform: translateY(-50%);
      width: 14px;
      height: 14px;
      color: var(--color-text-tertiary);
    }

    .mobile-nav-search .search-icon svg {
      width: 100%;
      height: 100%;
    }

    /* ========== Scroll to Top ========== */
    .scroll-top-btn {
      position: fixed;
      bottom: var(--sp-3xl);
      right: var(--sp-3xl);
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      color: var(--color-text);
      box-shadow: 0 2px 12px rgba(0,0,0,0.08), 0 0 0 0.5px rgba(0,0,0,0.06);
      display: flex;
      align-items: center;
      justify-content: center;
      z-index: 90;
      opacity: 0;
      transform: translateY(16px) scale(0.9);
      pointer-events: none;
      transition: opacity var(--dur-normal) var(--ease-out-quint),
                  transform var(--dur-normal) var(--ease-spring-soft),
                  background var(--dur-fast);
    }

    .scroll-top-btn.visible {
      opacity: 1;
      transform: translateY(0) scale(1);
      pointer-events: auto;
      animation: scrollBtnFloat 2.8s var(--ease-in-out-quart) infinite;
    }

    .scroll-top-btn:hover {
      background: var(--color-bg);
      box-shadow: 0 6px 20px rgba(0,0,0,0.12), 0 0 1px rgba(0,0,0,0.1);
      transform: translateY(-3px) scale(1.05);
      animation: none;
    }

    .scroll-top-btn:active {
      transform: scale(0.92);
      transition-duration: var(--dur-micro);
      animation: none;
    }

    .scroll-top-btn svg {
      width: 18px;
      height: 18px;
    }

    /* 스크롤 버튼 부유 효과 — 생물적 호흡감 */
    @keyframes scrollBtnFloat {
      0%, 100% { transform: translateY(0) scale(1); }
      50% { transform: translateY(-4px) scale(1); }
    }

    /* ========== Payment Result ========== */
    .payment-view-content {
      min-height: 60vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: var(--sp-5xl) 0;
    }

    .payment-processing {
      text-align: center;
      color: var(--color-text-secondary);
    }

    .payment-processing .spinner {
      width: 36px;
      height: 36px;
      border-color: rgba(0,0,0,0.08);
      border-top-color: var(--color-primary);
      margin-bottom: var(--sp-xl);
    }

    .payment-processing p {
      font-size: 16px;
      font-weight: 500;
    }

    .payment-result {
      text-align: center;
      max-width: 480px;
      width: 100%;
      background: var(--color-surface);
      border-radius: var(--radius-xl);
      padding: var(--sp-5xl) var(--sp-3xl);
      box-shadow: var(--shadow-card);
    }

    .payment-result h2 {
      font-size: 22px;
      font-weight: 700;
      letter-spacing: -0.5px;
      margin-bottom: var(--sp-md);
      color: var(--color-text);
    }

    .payment-result p {
      font-size: 15px;
      color: var(--color-text-secondary);
      line-height: 1.6;
    }

    .payment-result-icon {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto var(--sp-2xl);
      font-size: 28px;
      font-weight: 700;
    }

    .payment-result-icon.success-icon {
      background: rgba(36,138,61,0.1);
      color: var(--color-success);
    }

    .payment-result-icon.error-icon {
      background: rgba(206,0,0,0.08);
      color: var(--color-primary);
    }

    .payment-info {
      margin: var(--sp-2xl) 0;
      padding: var(--sp-xl);
      background: var(--color-bg);
      border-radius: var(--radius-md);
      text-align: left;
    }

    .payment-info-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: var(--sp-sm) 0;
    }

    .payment-info-row + .payment-info-row {
      border-top: 1px solid var(--color-border);
    }

    .payment-info-row .label {
      font-size: 14px;
      color: var(--color-text-secondary);
    }

    .payment-info-row .value {
      font-size: 14px;
      font-weight: 600;
      color: var(--color-text);
    }

    .payment-actions {
      margin-top: var(--sp-2xl);
      display: flex;
      flex-direction: column;
      gap: var(--sp-sm);
    }

    .payment-actions .btn-purchase {
      width: 100%;
    }

    .btn-secondary {
      width: 100%;
      padding: var(--sp-lg) var(--sp-2xl);
      font-size: 15px;
      font-weight: 600;
      color: var(--color-text);
      background: var(--color-bg);
      border: 1px solid var(--color-border-strong);
      border-radius: var(--radius-md);
      cursor: pointer;
      transition: background 0.2s, border-color 0.2s;
    }

    .btn-secondary:hover {
      background: var(--color-surface);
      border-color: var(--color-text-tertiary);
    }

    .payment-error-code {
      margin-top: var(--sp-lg);
      font-size: 13px;
      color: var(--color-text-tertiary);
      font-family: 'SF Mono', 'Fira Code', monospace;
    }

    /* ========== Responsive ========== */
    @media (max-width: 960px) {
      /* .book-grid 열수는 새 기본 정의를 따름 (모바일 2 / 768+ 3 / 1280+ 4) */
      .hero h1 { font-size: 52px; letter-spacing: -2.5px; }
      .hero { padding: var(--sp-8xl) 0 var(--sp-6xl); }
      .detail-layout {
        grid-template-columns: 320px 1fr;
        gap: var(--sp-4xl);
      }
    }

    @media (max-width: 768px) {
      :root { --page-pad: 20px; }

      .book-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--sp-md);
      }

      .detail-layout {
        grid-template-columns: 1fr;
        gap: var(--sp-3xl);
      }

      .detail-cover {
        max-width: 320px;
        margin: 0 auto;
      }

      .detail-info { position: static; }

      .hero h1 {
        font-size: 38px;
        letter-spacing: -1.8px;
      }

      .hero p { font-size: 17px; }
      .hero { padding: var(--sp-7xl) 0 var(--sp-5xl); }

      .header-search { display: none; }
      .header-nav { display: none; }
      .mobile-menu-btn { display: flex; }

      .category-bar {
        width: fit-content;
        max-width: 100%;
        overflow-x: auto;
      }

      .footer-top {
        flex-direction: column;
        gap: var(--sp-md);
        text-align: center;
      }

      .footer-links { justify-content: center; }
    }

    @media (max-width: 640px) {
      .hero h1 { font-size: 34px; letter-spacing: -1.5px; }
      .hero { padding: var(--sp-6xl) 0 var(--sp-4xl); }
      .hero-cta { font-size: 14px; padding: var(--sp-md) var(--sp-2xl); }

      .book-card-body {
        padding: var(--sp-lg);
      }

      .book-card-title { font-size: 14px; }
      .book-card-price { font-size: 15px; }
      .book-card-author { font-size: 12px; }
      .book-card-cta { display: none; }

      .detail-info h1 { font-size: 28px; letter-spacing: -1px; }
      .detail-price { font-size: 32px; }

      .purchase-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--sp-md);
      }

      .btn-read { width: 100%; text-align: center; }

      .my-header h2 { font-size: 26px; }

      .payment-result { padding: var(--sp-3xl) var(--sp-xl); }
      .payment-result h2 { font-size: 20px; }

      .coupon-wallet-card { flex-direction: column; }
      .coupon-wallet-left {
        flex-direction: row;
        min-width: unset;
        padding: var(--sp-md) var(--sp-lg);
      }
      .coupon-wallet-divider {
        width: 100%;
        height: 1px;
        background: repeating-linear-gradient(
          to right,
          var(--color-border-strong) 0,
          var(--color-border-strong) 4px,
          transparent 4px,
          transparent 8px
        );
      }
      .coupon-wallet-discount { font-size: 18px; }
    }

    @media (max-width: 375px) {
      :root { --page-pad: 16px; }
      .book-grid { grid-template-columns: 1fr; }
      .hero h1 { font-size: 26px; letter-spacing: -1px; }
      .hero p { font-size: 15px; }
      .hero { padding: var(--sp-5xl) 0 var(--sp-3xl); }
      .book-card-body { padding: var(--sp-md); }
      .book-card-title { font-size: 14px; }
      .book-card-price { font-size: 14px; }
      .detail-info h1 { font-size: 24px; letter-spacing: -0.8px; }
      .detail-price { font-size: 28px; letter-spacing: -1px; }
      .detail-price-section { padding: var(--sp-2xl); }
      .modal { padding: var(--sp-3xl); }
      .modal h2 { font-size: 20px; }
      .my-header h2 { font-size: 22px; }
      .category-tag { font-size: 12px; padding: var(--sp-sm) var(--sp-lg); }
    }

    /* ========== CSP 대응: 인라인 style 대체 클래스 ========== */
    .login-modal-logo {
      font-family: var(--font-en);
      font-size: 22px;
      font-weight: 800;
      letter-spacing: -0.6px;
      margin-bottom: var(--sp-2xl);
    }

    .login-modal-logo .accent,
    .footer-logo .accent {
      color: var(--color-primary);
    }

    /* ========== Placeholder Cover (커버 이미지 없는 상품) ========== */
    .placeholder-cover {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      width: 100%;
      height: 100%;
      padding: var(--sp-2xl) var(--sp-xl);
      position: relative;
      overflow: hidden;
      color: #fff;
    }

    /* 카테고리별 배경 그라디언트 */
    .placeholder-cover[data-category="투자"] {
      background: linear-gradient(155deg, #1a2a4a 0%, #0d1f3c 45%, #162d50 100%);
    }
    .placeholder-cover[data-category="자기계발"] {
      background: linear-gradient(155deg, #3d2b1f 0%, #2a1d14 45%, #4a3728 100%);
    }
    .placeholder-cover[data-category="default"] {
      background: linear-gradient(155deg, #2d2d3a 0%, #1e1e28 45%, #353545 100%);
    }

    /* 장식 패턴 (우측 상단 원형 그라디언트) */
    .placeholder-cover::before {
      content: '';
      position: absolute;
      top: -30%;
      right: -20%;
      width: 70%;
      height: 70%;
      border-radius: 50%;
      opacity: 0.08;
      pointer-events: none;
    }
    .placeholder-cover[data-category="투자"]::before {
      background: radial-gradient(circle, #4a9eff, transparent 70%);
    }
    .placeholder-cover[data-category="자기계발"]::before {
      background: radial-gradient(circle, #ffb347, transparent 70%);
    }
    .placeholder-cover[data-category="default"]::before {
      background: radial-gradient(circle, #a0a0c0, transparent 70%);
    }

    /* 하단 장식 라인 */
    .placeholder-cover::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 3px;
    }
    .placeholder-cover[data-category="투자"]::after {
      background: linear-gradient(90deg, #4a9eff, #2d6fcf, transparent);
    }
    .placeholder-cover[data-category="자기계발"]::after {
      background: linear-gradient(90deg, #ffb347, #e08a2e, transparent);
    }
    .placeholder-cover[data-category="default"]::after {
      background: linear-gradient(90deg, #888, #666, transparent);
    }

    .placeholder-cover-icon {
      width: 28px;
      height: 28px;
      opacity: 0.5;
      flex-shrink: 0;
    }

    .placeholder-cover-body {
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      gap: var(--sp-xs);
      min-height: 0;
      position: relative;
      z-index: 1;
    }

    .placeholder-cover-category {
      font-size: 10px;
      font-weight: 600;
      letter-spacing: 1.5px;
      text-transform: uppercase;
      opacity: 0.5;
    }
    .placeholder-cover[data-category="투자"] .placeholder-cover-category {
      color: #6db3ff;
    }
    .placeholder-cover[data-category="자기계발"] .placeholder-cover-category {
      color: #ffcb80;
    }

    .placeholder-cover-title {
      font-size: 14px;
      font-weight: 700;
      line-height: 1.35;
      letter-spacing: -0.3px;
      display: -webkit-box;
      -webkit-line-clamp: 3;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    .placeholder-cover-author {
      font-size: 11px;
      opacity: 0.45;
      font-weight: 500;
    }

    .placeholder-cover-brand {
      font-size: 9px;
      letter-spacing: 2px;
      font-weight: 700;
      opacity: 0.2;
      position: relative;
      z-index: 1;
      text-align: right;
      margin-top: var(--sp-sm);
    }

    /* 상세 페이지 - 더 큰 사이즈 */
    .detail-cover .placeholder-cover {
      padding: var(--sp-4xl) var(--sp-3xl);
    }
    .detail-cover .placeholder-cover-icon {
      width: 40px;
      height: 40px;
    }
    .detail-cover .placeholder-cover-category {
      font-size: 12px;
      letter-spacing: 2px;
    }
    .detail-cover .placeholder-cover-title {
      font-size: 22px;
      letter-spacing: -0.5px;
      -webkit-line-clamp: 4;
    }
    .detail-cover .placeholder-cover-author {
      font-size: 14px;
    }
    .detail-cover .placeholder-cover-brand {
      font-size: 11px;
      letter-spacing: 3px;
    }

    /* 마이페이지 구매 목록 - 작은 사이즈 */
    .purchase-item-cover .placeholder-cover {
      padding: var(--sp-sm) var(--sp-sm);
    }
    .purchase-item-cover .placeholder-cover-icon {
      display: none;
    }
    .purchase-item-cover .placeholder-cover-category {
      display: none;
    }
    .purchase-item-cover .placeholder-cover-title {
      font-size: 9px;
      -webkit-line-clamp: 2;
      line-height: 1.2;
    }
    .purchase-item-cover .placeholder-cover-author {
      display: none;
    }
    .purchase-item-cover .placeholder-cover-brand {
      display: none;
    }

    /* 다크 모드 미세 조정 */
    [data-theme="dark"] .placeholder-cover[data-category="투자"] {
      background: linear-gradient(155deg, #0f1d35 0%, #091428 45%, #132640 100%);
    }
    [data-theme="dark"] .placeholder-cover[data-category="자기계발"] {
      background: linear-gradient(155deg, #2e2015 0%, #1f150d 45%, #382a1e 100%);
    }
    [data-theme="dark"] .placeholder-cover[data-category="default"] {
      background: linear-gradient(155deg, #1e1e28 0%, #15151d 45%, #25253a 100%);
    }

    /* PDF 뷰어: viewFadeIn 애니메이션의 transform이 containing block을 생성하여
       .reader-wrapper(position:fixed)가 뷰포트 대신 높이 0 부모 기준이 됨 → 비활성화 */
    #view-reader.active {
      animation: none;
    }

    /* ========== PDF 뷰어 ========== */
    .reader-wrapper {
      position: fixed;
      inset: 0;
      z-index: 1000;
      display: flex;
      flex-direction: column;
      background: var(--color-bg);
    }

    .reader-toolbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: var(--sp-sm) var(--sp-lg);
      background: var(--color-surface);
      border-bottom: 1px solid var(--color-border);
      min-height: 52px;
      gap: var(--sp-sm);
      flex-shrink: 0;
      z-index: 10;
    }

    .reader-toolbar-left,
    .reader-toolbar-center,
    .reader-toolbar-right {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
    }

    .reader-toolbar-left {
      flex: 1;
      min-width: 0;
    }

    .reader-toolbar-center {
      flex-shrink: 0;
    }

    .reader-toolbar-right {
      flex: 1;
      justify-content: flex-end;
    }

    .reader-btn {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: var(--sp-xs);
      padding: var(--sp-sm);
      border: none;
      background: transparent;
      color: var(--color-text);
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: background 0.15s ease, color 0.15s ease;
      font-family: var(--font);
      font-size: 14px;
      min-width: 36px;
      min-height: 36px;
    }

    .reader-btn:hover {
      background: var(--color-primary-bg);
    }

    .reader-btn:active {
      background: var(--color-border);
    }

    .reader-btn:focus-visible {
      outline: 2px solid var(--color-primary);
      outline-offset: 2px;
    }

    .reader-btn svg {
      width: 18px;
      height: 18px;
      flex-shrink: 0;
    }

    /* 일괄 저장 버튼 — 데스크톱에서는 숨기고 모바일에서만 표시 */
    .reader-batch-save-btn {
      display: none;
    }

    .reader-batch-save-btn.saving {
      opacity: 0.6;
      pointer-events: none;
    }

    .reader-btn.bookmarked svg {
      fill: var(--color-primary);
      stroke: var(--color-primary);
    }

    .reader-btn-label {
      font-size: 14px;
      font-weight: 500;
      white-space: nowrap;
    }

    .reader-title {
      font-size: 14px;
      font-weight: 600;
      color: var(--color-text);
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      max-width: 200px;
    }

    .reader-page-info {
      display: flex;
      align-items: center;
      gap: var(--sp-xs);
      font-size: 14px;
      color: var(--color-text-secondary);
      font-variant-numeric: tabular-nums;
    }

    .reader-page-input {
      width: 48px;
      padding: var(--sp-xs) var(--sp-sm);
      border: 1px solid var(--color-border-strong);
      border-radius: var(--radius-xs);
      text-align: center;
      font-size: 14px;
      font-family: var(--font);
      color: var(--color-text);
      background: var(--color-surface);
      -moz-appearance: textfield;
    }

    .reader-page-input::-webkit-inner-spin-button,
    .reader-page-input::-webkit-outer-spin-button {
      -webkit-appearance: none;
      margin: 0;
    }

    .reader-page-input:focus {
      outline: none;
      border-color: var(--color-primary);
      box-shadow: 0 0 0 3px var(--color-primary-bg);
    }

    .reader-fontsize-btn {
      position: relative;
      min-width: 36px;
      justify-content: center;
    }

    .reader-fontsize-label {
      font-weight: 700;
      color: currentColor;
      line-height: 1;
      font-family: inherit;
    }

    .reader-fontsize-label.small {
      font-size: 13px;
    }

    .reader-fontsize-label.big {
      font-size: 18px;
    }

    /* 뷰어 콘텐츠 영역 — flex, 자식은 margin:auto로 센터링 */
    .reader-content {
      flex: 1;
      overflow: auto;
      display: flex;
      padding: var(--sp-sm);
      background: #e8e8ed;
      -webkit-overflow-scrolling: touch;
    }

    [data-theme="dark"] .reader-content {
      background: #111111;
    }

    /* 캔버스 래퍼 기본 (수동 줌 모드) — margin:auto로 중앙, overflow 시 좌상단 정렬 */
    .reader-canvas-wrap {
      position: relative;
      background: #ffffff;
      box-shadow: 0 2px 20px rgba(0,0,0,0.12);
      border-radius: 2px;
      line-height: 0;
      user-select: none;
      -webkit-user-select: none;
      -webkit-touch-callout: none;
      margin: auto;
    }

    [data-theme="dark"] .reader-canvas-wrap {
      box-shadow: 0 2px 20px rgba(0,0,0,0.4);
    }

    /* FIT-CONTAIN 모드: flex 동적 높이로 부모 남은 공간 전체 차지 → 캔버스 contain-fit */
    .reader-canvas-wrap.fit-contain {
      flex: 1 1 0;
      min-height: 0;
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
      background: transparent;
      box-shadow: none;
      border-radius: 0;
      margin: 0;
      overflow: hidden;
    }

    [data-theme="dark"] .reader-canvas-wrap.fit-contain {
      box-shadow: none;
    }

    .reader-canvas-wrap canvas {
      display: block;
      image-rendering: auto;
      -webkit-font-smoothing: antialiased;
    }

    /* PDF 링크 오버레이 — 캔버스 위에 투명 <a> 배치하여 하이퍼링크 클릭 지원 */
    .reader-link-overlay {
      position: absolute;
      pointer-events: none;
      z-index: 2;
      overflow: hidden;
    }
    .reader-pdf-link {
      position: absolute;
      display: block;
      pointer-events: auto;
      cursor: pointer;
      border-radius: 2px;
      touch-action: manipulation;
      -webkit-user-select: auto;
      user-select: auto;
    }
    .reader-pdf-link:hover {
      background: rgba(0, 102, 204, 0.15);
      outline: 1px solid rgba(0, 102, 204, 0.4);
    }

    /* FIT-CONTAIN 캔버스: JS가 contain-fit 크기를 계산하여 명시적으로 설정 → 페이지 비율 유지 */
    .reader-canvas-wrap.fit-contain canvas {
      background: #ffffff;
      box-shadow: 0 2px 20px rgba(0,0,0,0.12);
      border-radius: 2px;
    }

    [data-theme="dark"] .reader-canvas-wrap.fit-contain canvas {
      box-shadow: 0 2px 20px rgba(0,0,0,0.4);
    }

    /* 듀얼 페이지 모드 (책 펼침) — 수동 줌 및 JS 기반 fit */
    .reader-canvas-wrap.dual-page {
      display: flex;
      flex-direction: row;
      gap: 2px;
      background: #e0e0e0;
    }

    [data-theme="dark"] .reader-canvas-wrap.dual-page {
      background: #222222;
    }

    .reader-canvas-wrap.dual-page canvas {
      flex: 0 0 auto;
    }

    /* 듀얼 + fit-contain: flex 동적 높이 제한 → 캔버스가 뷰포트 초과 방지 */
    .reader-canvas-wrap.dual-page.fit-contain {
      flex: 1 1 0;
      min-height: 0;
      overflow: hidden;
      align-items: center;
      justify-content: center;
      background: transparent;
      box-shadow: none;
      border-radius: 0;
      margin: 0;
    }

    /* 에디터 생성 도서 챕터 HTML 뷰어 */
    .reader-chapter-wrap {
      flex: 1;
      max-width: 720px;
      margin: 0 auto;
      padding: var(--sp-xl) var(--sp-lg);
      background: #ffffff;
      box-shadow: 0 2px 20px rgba(0,0,0,0.12);
      border-radius: 2px;
      overflow-y: auto;
      line-height: 1.8;
      font-size: 16.5px;
      color: var(--color-text);
    }

    [data-theme="dark"] .reader-chapter-wrap {
      background: #1a1a1a;
      color: #e5e5e7;
      box-shadow: 0 2px 20px rgba(0,0,0,0.4);
    }

    .reader-chapter-title {
      font-size: 1.6em;
      font-weight: 700;
      margin-bottom: var(--sp-xl);
      padding-bottom: var(--sp-md);
      border-bottom: 2px solid var(--color-border);
      color: var(--color-text);
    }

    [data-theme="dark"] .reader-chapter-title {
      color: #f0f0f2;
      border-bottom-color: #333;
    }

    .reader-chapter-body {
      word-break: keep-all;
      overflow-wrap: break-word;
    }

    .reader-chapter-body h1 { font-size: 1.5em; font-weight: 700; margin: var(--sp-xl) 0 var(--sp-md); }
    .reader-chapter-body h2 { font-size: 1.3em; font-weight: 700; margin: var(--sp-lg) 0 var(--sp-sm); }
    .reader-chapter-body h3 { font-size: 1.15em; font-weight: 600; margin: var(--sp-md) 0 var(--sp-xs); }
    .reader-chapter-body p { margin-bottom: var(--sp-md); text-indent: 1em; }
    .reader-chapter-body p:first-child { text-indent: 0; }
    .reader-chapter-body blockquote {
      margin: var(--sp-md) 0;
      padding: var(--sp-sm) var(--sp-md);
      border-left: 3px solid var(--color-primary);
      background: rgba(0,0,0,0.02);
      border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    }
    [data-theme="dark"] .reader-chapter-body blockquote { background: rgba(255,255,255,0.04); }
    .reader-chapter-body ul, .reader-chapter-body ol { margin: var(--sp-sm) 0; padding-left: var(--sp-xl); }
    .reader-chapter-body li { margin-bottom: var(--sp-xs); text-indent: 0; }
    .reader-chapter-body img { max-width: 100%; border-radius: var(--radius-sm); margin: var(--sp-lg) 0; }
    .reader-chapter-body hr {
      border: none; text-align: center; margin: var(--sp-xl) 0;
      color: var(--color-text-secondary);
    }
    .reader-chapter-body hr::after { content: '• • •'; }
    .reader-chapter-body table { width: 100%; border-collapse: collapse; margin: var(--sp-md) 0; }
    .reader-chapter-body th, .reader-chapter-body td { padding: var(--sp-xs) var(--sp-sm); border: 1px solid var(--color-border); }
    .reader-chapter-body th { background: rgba(0,0,0,0.04); font-weight: 600; }
    [data-theme="dark"] .reader-chapter-body th { background: rgba(255,255,255,0.06); }
    .reader-chapter-body code { background: rgba(0,0,0,0.05); padding: 2px 6px; border-radius: 4px; font-size: 0.9em; }
    [data-theme="dark"] .reader-chapter-body code { background: rgba(255,255,255,0.08); }
    .reader-chapter-body pre {
      background: #1e1e2e; color: #cdd6f4; padding: var(--sp-md); border-radius: var(--radius-sm);
      overflow-x: auto; margin: var(--sp-md) 0; font-size: 0.9em;
    }
    .reader-chapter-body pre code { background: none; padding: 0; color: inherit; }
    .reader-chapter-body a { color: var(--color-primary); text-decoration: underline; }
    .reader-chapter-body strong { font-weight: 700; }
    .reader-chapter-body em { font-style: italic; }

    .reader-chapter-empty {
      text-align: center;
      color: var(--color-text-secondary);
      padding: var(--sp-xxl) 0;
      font-size: 0.95em;
    }

    /* 진행률 바 */
    .reader-progress {
      height: 3px;
      background: var(--color-border);
      flex-shrink: 0;
    }

    .reader-progress-bar {
      height: 100%;
      background: var(--color-primary);
      transition: width var(--dur-normal) var(--ease-out-expo);
      width: 0%;
    }

    /* 북마크 패널 */
    .reader-bookmark-panel {
      position: absolute;
      top: 52px;
      right: 0;
      bottom: 0;
      width: 280px;
      background: var(--color-surface);
      border-left: 1px solid var(--color-border);
      box-shadow: -4px 0 20px rgba(0,0,0,0.08);
      z-index: 20;
      display: flex;
      flex-direction: column;
      transform: translateX(100%);
      transition: transform var(--dur-normal) var(--ease-out-expo);
    }
    .reader-bookmark-panel.active {
      transform: translateX(0);
    }
    .reader-bookmark-panel-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: var(--sp-base) var(--sp-lg);
      border-bottom: 1px solid var(--color-border);
      flex-shrink: 0;
    }
    .reader-bookmark-panel-title {
      font-size: 15px;
      font-weight: 600;
    }
    .reader-bookmark-panel-close svg {
      width: 16px;
      height: 16px;
    }
    .reader-bookmark-list {
      flex: 1;
      overflow-y: auto;
      padding: var(--sp-sm);
    }
    .reader-bookmark-empty {
      text-align: center;
      padding: var(--sp-3xl) var(--sp-lg);
      color: var(--color-text-tertiary);
      font-size: 13px;
      line-height: 1.6;
    }
    .reader-bookmark-item {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
      width: 100%;
      padding: var(--sp-sm) var(--sp-md);
      border: none;
      background: transparent;
      color: var(--color-text);
      border-radius: var(--radius-sm);
      cursor: pointer;
      font-family: var(--font);
      font-size: 13px;
      text-align: left;
      transition: background 0.15s;
    }
    .reader-bookmark-item:hover {
      background: var(--color-primary-bg);
    }
    .reader-bookmark-item.current {
      background: var(--color-primary-bg);
      color: var(--color-primary);
      font-weight: 600;
    }
    .reader-bookmark-item svg {
      width: 16px;
      height: 16px;
      flex-shrink: 0;
      stroke: var(--color-primary);
      fill: var(--color-primary);
    }
    .reader-bookmark-item-label {
      flex: 1;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    .reader-bookmark-item-page {
      flex-shrink: 0;
      font-size: 12px;
      color: var(--color-text-tertiary);
      font-variant-numeric: tabular-nums;
    }

    @media (max-width: 640px) {
      .reader-bookmark-panel {
        width: 100%;
        top: 0;
      }
      .reader-bookmark-panel-header {
        padding-top: var(--sp-lg);
      }
    }

    /* 뷰어 로딩 상태 */
    .reader-loading {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      height: 100%;
      width: 100%;
      gap: var(--sp-lg);
      color: var(--color-text-secondary);
      font-size: 15px;
    }

    /* 뷰어 에러 상태 */
    .reader-error {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      height: 100%;
      width: 100%;
      gap: var(--sp-lg);
      text-align: center;
      padding: var(--sp-3xl);
    }

    .reader-error-icon {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      background: var(--color-primary-bg);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 28px;
      color: var(--color-primary);
    }

    .reader-error h3 {
      font-size: 18px;
      font-weight: 600;
      color: var(--color-text);
    }

    .reader-error p {
      font-size: 14px;
      color: var(--color-text-secondary);
      max-width: 360px;
      line-height: 1.6;
    }

    .reader-error-btn {
      margin-top: var(--sp-sm);
      padding: var(--sp-md) var(--sp-2xl);
      border: none;
      border-radius: var(--radius-pill);
      background: var(--color-primary);
      color: #fff;
      font-size: 15px;
      font-weight: 600;
      font-family: var(--font);
      cursor: pointer;
      transition: background 0.15s ease;
    }

    .reader-error-btn:hover {
      background: var(--color-primary-hover);
    }

    /* ─── 미리보기 잠금 화면 ─── */
    .reader-preview-lock {
      display: flex;
      align-items: center;
      justify-content: center;
      height: 100%;
      width: 100%;
      padding: var(--sp-3xl);
    }

    .reader-preview-lock-card {
      max-width: 440px;
      text-align: center;
      background: var(--color-surface);
      border: 1px solid var(--color-border);
      border-radius: var(--radius-xl);
      padding: var(--sp-5xl) var(--sp-4xl);
      box-shadow: var(--shadow-elevated);
    }

    [data-theme="dark"] .reader-preview-lock-card {
      background: var(--color-surface);
    }

    .reader-preview-lock-icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 64px;
      height: 64px;
      margin-bottom: var(--sp-xl);
      color: var(--color-primary);
      background: var(--color-primary-bg);
      border-radius: 50%;
    }

    .reader-preview-lock-icon svg {
      width: 28px;
      height: 28px;
    }

    .reader-preview-lock-card h3 {
      font-size: 22px;
      font-weight: 700;
      letter-spacing: -0.8px;
      margin-bottom: var(--sp-md);
      color: var(--color-text);
    }

    .reader-preview-lock-card p {
      font-size: 14px;
      color: var(--color-text-secondary);
      line-height: 1.7;
      margin-bottom: var(--sp-2xl);
    }

    .reader-preview-lock-actions {
      display: flex;
      flex-direction: column;
      gap: var(--sp-sm);
    }

    .reader-preview-lock-btn {
      padding: var(--sp-md) var(--sp-2xl);
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-pill);
      border: none;
      cursor: pointer;
      font-family: var(--font);
      transition: background 0.15s ease, transform var(--dur-fast) var(--ease-spring-soft);
    }

    .reader-preview-lock-btn.primary {
      background: var(--color-primary);
      color: #fff;
    }

    .reader-preview-lock-btn.primary:hover {
      background: var(--color-primary-hover);
      transform: translateY(-1px);
    }

    .reader-preview-lock-btn.ghost {
      background: transparent;
      color: var(--color-text-secondary);
      border: 1px solid var(--color-border-strong);
    }

    .reader-preview-lock-btn.ghost:hover {
      background: rgba(0,0,0,0.04);
    }

    [data-theme="dark"] .reader-preview-lock-btn.ghost:hover {
      background: rgba(255,255,255,0.06);
    }

    /* ─── 상세 페이지 미리보기 버튼 ─── */
    .btn-preview {
      width: 100%;
      margin-top: var(--sp-sm);
      padding: var(--sp-md) var(--sp-2xl);
      font-size: 14px;
      font-weight: 600;
      color: var(--color-text-secondary);
      background: transparent;
      border: 1px solid var(--color-border-strong);
      border-radius: var(--radius-pill);
      cursor: pointer;
      font-family: var(--font);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      transition: background 0.15s ease, color 0.15s ease, transform var(--dur-fast) var(--ease-spring-soft);
    }

    .btn-preview:hover {
      color: var(--color-text);
      background: rgba(0,0,0,0.03);
      transform: translateY(-1px);
    }

    [data-theme="dark"] .btn-preview:hover,
    body.premium-mode .btn-preview:hover {
      background: rgba(255,255,255,0.05);
    }

    body.premium-mode .btn-preview {
      color: var(--premium-text-secondary);
      border-color: var(--premium-border-strong);
    }

    body.premium-mode .btn-preview:hover {
      color: var(--premium-text);
    }

    /* 인쇄 차단 — 뷰어 활성 시에만 적용 */
    @media print {
      #view-reader.active * {
        display: none !important;
      }
      #view-reader.active::after {
        content: '이 콘텐츠는 인쇄할 수 없습니다.';
        display: block !important;
        text-align: center;
        padding: var(--sp-4xl);
        font-size: 18px;
        color: var(--color-text-tertiary);
      }
    }

    /* 뷰어 반응형 */
    @media (max-width: 768px) {
      .reader-toolbar {
        padding: var(--sp-xs) var(--sp-sm);
        min-height: 44px;
        flex-wrap: wrap;
      }

      .reader-toolbar-left {
        order: 1;
        flex: 0 0 auto;
      }

      .reader-toolbar-center {
        order: 3;
        flex: 1 0 100%;
        justify-content: center;
        padding-top: var(--sp-xs);
        border-top: 1px solid var(--color-border);
        margin-top: var(--sp-xs);
      }

      .reader-toolbar-right {
        order: 2;
        flex: 0 0 auto;
      }

      .reader-btn-label {
        display: none;
      }

      .reader-title {
        display: none;
      }

      .reader-content {
        padding: var(--sp-sm);
      }

      .reader-chapter-wrap {
        padding: var(--sp-lg) var(--sp-md);
      }

      .reader-chapter-title {
        font-size: 1.3em;
      }

      /* 모바일에서 일괄 저장 버튼 표시 */
      .reader-batch-save-btn {
        display: flex;
      }

    }

    @media (max-width: 480px) {
      .reader-toolbar-right #readerDarkMode {
        display: none;
      }

      .reader-page-input {
        width: 40px;
        padding: var(--sp-xs) var(--sp-xs);
        font-size: 13px;
      }

      .reader-chapter-wrap {
        padding: var(--sp-md) var(--sp-sm);
      }
    }

    /* ===== 에디터 프로필 페이지 ===== */
    .editor-profile-header {
      display: flex;
      gap: var(--sp-2xl);
      align-items: flex-start;
      padding: var(--sp-3xl) 0;
      border-bottom: 1px solid var(--color-border);
      margin-bottom: var(--sp-3xl);
    }

    .editor-avatar {
      width: 88px;
      height: 88px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--color-primary-bg) 0%, rgba(206,0,0,0.12) 100%);
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      box-shadow: 0 2px 12px rgba(206,0,0,0.08);
    }

    .editor-avatar-icon {
      font-size: 36px;
      line-height: 1;
      color: var(--color-primary);
    }

    .editor-info {
      flex: 1;
      min-width: 0;
    }

    .editor-name {
      font-size: 28px;
      font-weight: 800;
      letter-spacing: -0.5px;
      margin: 0 0 var(--sp-sm) 0;
      color: var(--color-text);
    }

    .editor-specialty {
      display: inline-block;
      font-size: 12px;
      font-weight: 600;
      color: var(--color-primary);
      background: var(--color-primary-bg);
      padding: var(--sp-xs) var(--sp-md);
      border-radius: var(--radius-pill);
      margin-bottom: var(--sp-md);
    }

    .editor-bio {
      font-size: 15px;
      color: var(--color-text-secondary);
      line-height: 1.7;
      margin: 0 0 var(--sp-lg) 0;
    }

    .editor-credentials {
      margin: 0 0 var(--sp-lg) 0;
      padding: var(--sp-md) var(--sp-lg);
      background: var(--color-bg);
      border-radius: var(--radius-sm);
      border: 1px solid var(--color-border);
    }
    .editor-credentials-label {
      display: block;
      font-size: 11px;
      font-weight: 600;
      color: var(--color-text-tertiary);
      text-transform: uppercase;
      letter-spacing: 0.5px;
      margin-bottom: var(--sp-xs);
    }
    .editor-credentials p {
      font-size: 14px;
      color: var(--color-text-secondary);
      line-height: 1.6;
      margin: 0;
    }

    .editor-stats {
      display: flex;
      gap: var(--sp-md);
    }

    .editor-stat {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-xs);
      font-size: 13px;
      color: var(--color-text-secondary);
      padding: var(--sp-xs) var(--sp-md);
      background: var(--color-bg);
      border-radius: var(--radius-pill);
      border: 1px solid var(--color-border);
    }

    .editor-stat strong {
      font-weight: 700;
      color: var(--color-text);
    }

    .editor-avatar-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      border-radius: 50%;
    }

    .editor-sns {
      display: flex;
      gap: var(--sp-sm);
      margin-top: var(--sp-md);
    }

    .editor-sns-link {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 32px;
      height: 32px;
      border-radius: 50%;
      color: var(--color-text-secondary);
      background: var(--color-bg);
      border: 1px solid var(--color-border);
      transition: color 0.2s, background 0.2s, border-color 0.2s;
    }

    .editor-sns-link:hover {
      color: var(--color-primary);
      background: var(--color-primary-bg);
      border-color: rgba(206,0,0,0.2);
    }

    .editor-sns-link svg {
      width: 16px;
      height: 16px;
    }

    .editor-books-section {
      padding-bottom: var(--sp-4xl);
    }

    .editor-books-title {
      font-size: 20px;
      font-weight: 700;
      margin: 0 0 var(--sp-xl) 0;
      color: var(--color-text);
    }

    /* 상세 페이지 저자 링크 */
    .detail-author-link {
      color: var(--color-primary);
      text-decoration: none;
      font-weight: 500;
      transition: opacity 0.15s;
    }

    .detail-author-link:hover {
      opacity: 0.7;
      text-decoration: underline;
    }

    /* 쿠폰 캡슐 토글 (내 서재) */
    .coupon-capsule-toggle {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-xs);
      padding: var(--sp-sm) var(--sp-xl);
      font-size: 13px;
      font-weight: 600;
      color: var(--color-primary);
      background: var(--color-primary-bg);
      border: 1.5px solid transparent;
      border-radius: var(--radius-pill);
      cursor: pointer;
      transition: background 0.2s, border-color 0.2s;
      margin-bottom: var(--sp-md);
      white-space: nowrap;
    }

    .coupon-capsule-toggle:hover {
      background: rgba(206,0,0,0.12);
      border-color: var(--color-primary);
    }

    .coupon-capsule-toggle.open {
      background: var(--color-primary);
      color: #fff;
      border-color: var(--color-primary);
    }

    .coupon-claim-expand {
      margin-top: var(--sp-md);
      animation: dropdownFadeIn var(--dur-fast) var(--ease-out-expo);
    }

    /* 쿠폰 캡슐 해제 버튼 (상세 페이지) */
    .coupon-capsule-clear {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 24px;
      height: 24px;
      border: none;
      border-radius: 50%;
      background: var(--color-border-strong);
      color: var(--color-text-secondary);
      font-size: 14px;
      cursor: pointer;
      margin-left: var(--sp-xs);
      transition: background 0.15s;
      vertical-align: middle;
    }

    .coupon-capsule-clear:hover {
      background: var(--color-primary);
      color: #fff;
    }

    @media (max-width: 640px) {
      .editor-profile-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: var(--sp-lg);
        padding: var(--sp-2xl) 0;
      }

      .editor-avatar {
        width: 72px;
        height: 72px;
      }

      .editor-avatar-icon {
        font-size: 28px;
      }

      .editor-name {
        font-size: 24px;
      }

      .editor-specialty {
        font-size: 11px;
      }

      .editor-stats {
        justify-content: center;
        flex-wrap: wrap;
        gap: var(--sp-sm);
      }

      .editor-stat {
        font-size: 12px;
      }

      .editor-sns {
        justify-content: center;
      }

      .editor-books-title {
        font-size: 18px;
      }

      .coupon-capsule-dropdown {
        max-width: 100%;
        left: 0;
        right: 0;
      }
    }

    /* ===== 쿠폰 캡슐 버튼 (상세 페이지) ===== */
    .coupon-capsule-wrap {
      margin-bottom: var(--sp-md);
      position: relative;
    }

    .coupon-capsule-btn {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-xs);
      padding: var(--sp-sm) var(--sp-xl);
      font-size: 13px;
      font-weight: 600;
      color: var(--color-primary);
      background: var(--color-primary-bg);
      border: 1.5px solid transparent;
      border-radius: var(--radius-pill);
      cursor: pointer;
      transition: background 0.2s, border-color 0.2s, color 0.2s;
      white-space: nowrap;
    }

    .coupon-capsule-btn:hover {
      background: rgba(206,0,0,0.12);
      border-color: var(--color-primary);
    }

    .coupon-capsule-btn.applied {
      background: var(--color-primary);
      color: #fff;
      border-color: var(--color-primary);
    }

    .coupon-capsule-dropdown {
      position: absolute;
      top: calc(100% + var(--sp-sm));
      left: 0;
      right: 0;
      max-width: 340px;
      background: var(--color-surface);
      border: 1.5px solid var(--color-border-strong);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-elevated);
      z-index: 20;
      overflow: hidden;
      animation: dropdownFadeIn var(--dur-fast) var(--ease-out-expo);
    }

    .coupon-dropdown-loading,
    .coupon-dropdown-empty {
      padding: var(--sp-xl);
      text-align: center;
      font-size: 13px;
      color: var(--color-text-tertiary);
      line-height: 1.5;
    }

    .coupon-dropdown-empty span {
      font-size: 11px;
      opacity: 0.7;
    }

    .coupon-dropdown-item {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
      width: 100%;
      padding: var(--sp-md) var(--sp-lg);
      border: none;
      border-bottom: 1px solid var(--color-border);
      background: transparent;
      cursor: pointer;
      text-align: left;
      font-size: 13px;
      color: var(--color-text);
      transition: background 0.15s;
    }

    .coupon-dropdown-item:last-child {
      border-bottom: none;
    }

    .coupon-dropdown-item:hover {
      background: var(--color-primary-bg);
    }

    .coupon-dropdown-discount {
      font-weight: 800;
      color: var(--color-primary);
      min-width: 44px;
      font-size: 14px;
    }

    .coupon-dropdown-label {
      font-size: 11px;
      color: var(--color-text-tertiary);
      flex-shrink: 0;
    }

    .coupon-dropdown-code {
      font-family: 'SF Mono', 'Fira Code', monospace;
      font-size: 11px;
      font-weight: 600;
      color: var(--color-text-secondary);
      letter-spacing: 0.5px;
      margin-left: auto;
    }

    .coupon-dropdown-cond {
      font-size: 10px;
      color: var(--color-text-tertiary);
    }

    /* ========== Premium 멤버 전용 페이지 ========== */
    /* body 클래스가 켜지면 본문 전반에 다크 + 골드 톤을 입혀 프리미엄 느낌을 준다 */
    :root {
      --premium-bg: #0a0a0c;
      --premium-bg-elevated: #15151a;
      --premium-surface: #1a1a20;
      --premium-surface-hover: #22222a;
      --premium-text: #f4f1e8;
      --premium-text-secondary: #b6b1a0;
      --premium-text-tertiary: #7d7a72;
      --premium-border: rgba(212, 175, 95, 0.18);
      --premium-border-strong: rgba(212, 175, 95, 0.38);
      --premium-gold: #d4af5f;
      --premium-gold-bright: #e8c878;
      --premium-gold-deep: #b8881f;
      --premium-gold-soft: rgba(212, 175, 95, 0.12);
      --premium-shadow-card: 0 2px 8px rgba(0,0,0,0.5), 0 0 0 1px rgba(212,175,95,0.06);
      --premium-shadow-card-hover: 0 16px 48px rgba(0,0,0,0.6), 0 0 0 1px rgba(212,175,95,0.22);
    }

    body.premium-mode {
      background: var(--premium-bg);
      color: var(--premium-text);
    }

    body.premium-mode .header {
      background: rgba(10,10,12,0.85);
      border-bottom: 1px solid var(--premium-border);
      backdrop-filter: saturate(180%) blur(20px);
      -webkit-backdrop-filter: saturate(180%) blur(20px);
    }

    body.premium-mode .logo {
      color: var(--premium-text);
    }

    body.premium-mode .logo .accent {
      color: var(--premium-gold-bright);
    }

    body.premium-mode .header-search input {
      background: rgba(255,255,255,0.05);
      color: var(--premium-text);
      border-color: var(--premium-border);
    }

    body.premium-mode .header-search input::placeholder {
      color: var(--premium-text-tertiary);
    }

    body.premium-mode .nav-link {
      color: var(--premium-text-secondary);
    }

    body.premium-mode .nav-link:hover,
    body.premium-mode .nav-link.active {
      color: var(--premium-gold-bright);
      background: var(--premium-gold-soft);
    }

    body.premium-mode .nav-link.cta {
      color: var(--premium-gold-bright);
    }

    body.premium-mode .footer {
      background: var(--premium-bg);
      color: var(--premium-text-tertiary);
      border-top: 1px solid var(--premium-border);
    }

    body.premium-mode .footer-logo .accent,
    body.premium-mode .footer a {
      color: var(--premium-gold);
    }

    /* ─── Hero (왼쪽 정렬 컴팩트) ─── */
    .premium-view {
      color: var(--premium-text);
    }

    .premium-hero {
      padding: var(--sp-5xl) 0 var(--sp-3xl);
      text-align: left;
    }

    .premium-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-sm);
      padding: 4px var(--sp-md);
      font-size: 10.5px;
      font-weight: 700;
      letter-spacing: 2px;
      color: var(--premium-gold-bright);
      background: var(--premium-gold-soft);
      border: 1px solid var(--premium-border-strong);
      border-radius: var(--radius-pill);
      margin-bottom: var(--sp-lg);
      font-family: var(--font-en);
      text-transform: uppercase;
    }

    .premium-eyebrow svg {
      width: 12px;
      height: 12px;
    }

    .premium-hero-title {
      font-size: 36px;
      font-weight: 800;
      letter-spacing: -1.6px;
      line-height: 1.2;
      margin-bottom: var(--sp-md);
      color: var(--premium-text);
      max-width: 720px;
    }

    /* −50% 강조 — 골드 톤 (빨간색 제거) */
    .premium-half {
      color: var(--premium-gold-bright);
      position: relative;
      display: inline-block;
      padding: 0 var(--sp-sm);
      font-family: var(--font-en);
    }

    .premium-half::before {
      content: '';
      position: absolute;
      inset: 0;
      background: var(--premium-gold-soft);
      border-radius: var(--radius-sm);
      transform: skew(-8deg);
      z-index: -1;
    }

    .premium-hero-sub {
      font-size: 15px;
      color: var(--premium-text-secondary);
      line-height: 1.6;
      letter-spacing: -0.3px;
      max-width: 640px;
      margin: 0;
    }

    /* 잘못된 링크 화면용 골드 버튼 (스토어로 돌아가기) */
    .premium-cta-btn {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-sm);
      padding: var(--sp-md) var(--sp-2xl);
      font-size: 14px;
      font-weight: 600;
      color: var(--premium-text);
      background: transparent;
      border: 1px solid var(--premium-border-strong);
      border-radius: var(--radius-pill);
      cursor: pointer;
      letter-spacing: -0.2px;
      transition: background var(--dur-fast) ease, transform var(--dur-fast) var(--ease-spring-soft);
    }

    .premium-cta-btn:hover {
      background: var(--premium-gold-soft);
      transform: translateY(-1px);
    }

    .premium-cta-btn--ghost {
      background: transparent;
    }

    /* ─── 잘못된 초대 링크 ─── */
    .premium-invalid {
      padding: var(--sp-8xl) 0 var(--sp-9xl);
    }

    .premium-invalid-card {
      max-width: 480px;
      margin: 0 auto;
      padding: var(--sp-5xl) var(--sp-4xl);
      text-align: center;
      background: var(--premium-surface);
      border: 1px solid var(--premium-border);
      border-radius: var(--radius-xl);
      box-shadow: var(--premium-shadow-card);
    }

    .premium-invalid-icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 56px;
      height: 56px;
      margin-bottom: var(--sp-xl);
      color: var(--premium-gold-bright);
      background: var(--premium-gold-soft);
      border-radius: 50%;
      border: 1px solid var(--premium-border-strong);
    }

    .premium-invalid-icon svg {
      width: 26px;
      height: 26px;
    }

    .premium-invalid-card h2 {
      font-size: 22px;
      font-weight: 700;
      letter-spacing: -0.8px;
      margin-bottom: var(--sp-md);
      color: var(--premium-text);
    }

    .premium-invalid-card > p {
      font-size: 14px;
      color: var(--premium-text-secondary);
      line-height: 1.7;
      margin-bottom: var(--sp-2xl);
    }

    /* ─── Catalog 섹션 ─── */
    .premium-catalog {
      padding-bottom: var(--sp-9xl);
      padding-top: var(--sp-lg);
    }

    /* 카테고리 바 다크 톤 */
    .premium-category-bar {
      background: rgba(255,255,255,0.04);
    }

    .premium-category-bar .category-tag {
      color: var(--premium-text-secondary);
    }

    .premium-category-bar .category-tag:hover {
      color: var(--premium-text);
    }

    .premium-category-bar .category-tag.active {
      background: var(--premium-gold);
      color: #0a0a0c;
      font-weight: 700;
    }

    /* ─── 프리미엄 도서 카드 ─── */
    .premium-book-grid .book-card {
      background: var(--premium-surface);
      border: 1px solid var(--premium-border);
      box-shadow: var(--premium-shadow-card);
    }

    .premium-book-grid .book-card:hover {
      box-shadow: var(--premium-shadow-card-hover);
      border-color: var(--premium-border-strong);
    }

    .premium-book-grid .book-card-cover {
      background: #1f1f24;
    }

    .premium-book-grid .book-card-title {
      color: var(--premium-text);
    }

    .premium-book-grid .book-card-author {
      color: var(--premium-text-tertiary);
    }

    .premium-book-grid .book-card-category {
      background: var(--premium-gold-soft);
      color: var(--premium-gold-bright);
    }

    .premium-book-grid .book-card-price {
      color: var(--premium-gold-bright);
      font-size: 19px;
    }

    .premium-book-grid .book-card:hover .book-card-price {
      color: var(--premium-gold-bright);
    }

    .premium-book-grid .book-card-price .original {
      color: var(--premium-text-tertiary);
      font-size: 12px;
    }

    .premium-book-grid .book-card-cta {
      color: var(--premium-gold-bright);
    }

    /* MEMBER −50% 강조 배지 (흰색 글래스) */
    .premium-book-grid .book-card-badge.premium-badge {
      background: rgba(255,255,255,0.95);
      color: #1d1d1f;
      backdrop-filter: blur(8px) saturate(180%);
      -webkit-backdrop-filter: blur(8px) saturate(180%);
      font-family: var(--font-en);
      font-size: 10.5px;
      font-weight: 800;
      letter-spacing: 0.6px;
      padding: 4px var(--sp-sm);
      box-shadow: 0 2px 8px rgba(0,0,0,0.18);
      animation: premiumBadgePulse 2.6s var(--ease-in-out-quart) infinite;
    }

    @keyframes premiumBadgePulse {
      0%, 100% { transform: scale(1); }
      50% { transform: scale(1.05); }
    }

    /* ─── 빈 상태 ─── */
    .premium-catalog .empty-state {
      color: var(--premium-text-tertiary);
    }

    /* ─── 모바일 ─── */
    @media (max-width: 768px) {
      .premium-hero {
        padding: var(--sp-3xl) 0 var(--sp-xl);
      }
      .premium-hero-title {
        font-size: 28px;
        letter-spacing: -1.2px;
      }
      .premium-hero-sub {
        font-size: 14px;
      }
      .premium-invalid-card {
        padding: var(--sp-3xl) var(--sp-2xl);
      }
      .hero {
        padding: var(--sp-3xl) 0 var(--sp-xl);
      }
      .hero h1 {
        font-size: 26px;
        letter-spacing: -1px;
      }
      .hero p {
        font-size: 14px;
      }
    }

    /* ─── 프리미엄 흐름이 detail 페이지까지 이어지도록 — body.premium-mode 변형 ─── */
    body.premium-mode .detail-back {
      color: var(--premium-gold-bright);
    }

    body.premium-mode .detail-cover {
      background: linear-gradient(160deg, #1f1f24 0%, #15151a 100%);
      box-shadow: 0 24px 60px rgba(0,0,0,0.5), 0 4px 16px rgba(0,0,0,0.3), 0 0 0 1px var(--premium-border);
    }

    body.premium-mode .detail-cover:hover {
      box-shadow: 0 32px 72px rgba(0,0,0,0.6), 0 6px 20px rgba(0,0,0,0.4), 0 0 0 1px var(--premium-border-strong);
    }

    body.premium-mode .detail-info h1 {
      color: var(--premium-text);
    }

    body.premium-mode .detail-category {
      color: var(--premium-gold-bright);
      background: var(--premium-gold-soft);
    }

    body.premium-mode .detail-author {
      color: var(--premium-text-secondary);
    }

    body.premium-mode .detail-author-link {
      color: var(--premium-gold-bright);
    }

    body.premium-mode .detail-rating {
      color: var(--premium-text-secondary);
    }

    body.premium-mode .detail-pitch {
      color: var(--premium-text);
      border-bottom-color: var(--premium-border);
    }

    body.premium-mode .detail-desc {
      color: var(--premium-text-secondary);
    }

    body.premium-mode .detail-price-section {
      background: var(--premium-surface);
      border: 1px solid var(--premium-border);
    }

    body.premium-mode .detail-price {
      color: var(--premium-text);
    }

    body.premium-mode .detail-price .original {
      color: var(--premium-text-tertiary);
    }

    body.premium-mode .detail-price-note {
      color: var(--premium-gold-bright);
      font-weight: 600;
    }

    body.premium-mode .detail-meta-row {
      border-bottom: 1px solid var(--premium-border);
    }

    body.premium-mode .detail-meta-row .label {
      color: var(--premium-text-tertiary);
    }

    body.premium-mode .detail-meta-row .value {
      color: var(--premium-text);
    }

    body.premium-mode .detail-toc {
      border-top: 1px solid var(--premium-border);
    }

    body.premium-mode .detail-toc-toggle {
      color: var(--premium-text);
    }

    body.premium-mode .detail-toc-toggle svg {
      color: var(--premium-gold);
    }

    body.premium-mode .detail-toc-content {
      color: var(--premium-text-secondary);
    }

    /* 프리미엄 모드의 구매 버튼: 빨강 → 골드 그라데이션 */
    body.premium-mode .btn-purchase {
      background: linear-gradient(135deg, var(--premium-gold-bright) 0%, var(--premium-gold) 100%);
      color: #1a1305;
      box-shadow: 0 8px 24px rgba(212,175,95,0.28);
    }

    body.premium-mode .btn-purchase:hover {
      background: linear-gradient(135deg, var(--premium-gold-bright) 0%, var(--premium-gold) 100%);
      box-shadow: 0 14px 36px rgba(212,175,95,0.48);
    }

    body.premium-mode .btn-purchase.purchased {
      background: var(--color-success);
      color: #fff;
    }

    /* 스켈레톤 로딩도 다크 톤 */
    body.premium-mode .skeleton-cover,
    body.premium-mode .skeleton-line,
    body.premium-mode .skeleton-detail-cover {
      background: linear-gradient(90deg, #1a1a20 25%, #22222a 50%, #1a1a20 75%);
      background-size: 200% 100%;
    }

    /* ─── 상세 페이지의 멤버 가격 (골드 톤 통일) ─── */
    .detail-member-row {
      margin-top: var(--sp-md);
      padding: var(--sp-md) var(--sp-lg);
      background: linear-gradient(135deg, rgba(212,175,95,0.1), rgba(212,175,95,0.03));
      border: 1px solid rgba(212,175,95,0.28);
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: var(--sp-md);
    }

    .detail-member-row .label {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 12px;
      font-weight: 700;
      color: var(--premium-gold-deep);
      letter-spacing: 0.5px;
    }

    [data-theme="dark"] .detail-member-row .label,
    body.premium-mode .detail-member-row .label {
      color: var(--premium-gold-bright);
    }

    .detail-member-row .value {
      font-size: 18px;
      font-weight: 800;
      color: var(--premium-gold-deep);
      font-family: var(--font-en);
    }

    [data-theme="dark"] .detail-member-row .value,
    body.premium-mode .detail-member-row .value {
      color: var(--premium-gold-bright);
    }

    .detail-member-row .saved {
      font-size: 11px;
      font-weight: 600;
      color: var(--premium-gold-deep);
      margin-left: 4px;
      opacity: 0.85;
    }

    body.premium-mode .detail-member-row .saved {
      color: var(--premium-gold);
    }

    /* ========== 강의 상세 (랜딩 페이지 iframe + floating CTA) ========== */
    /* view-course 가 활성일 때 body 에 .course-active 추가됨
       → 불스터디 헤더/푸터 숨김 + 스크롤 잠금 (랜딩 페이지의 자체 헤더만 보임) */
    body.course-active { overflow: hidden; }
    body.course-active .header { display: none; }
    body.course-active .footer { display: none; }
    body.course-active .scroll-top-btn { display: none !important; }

    /* view-course 자체를 화면 전체로 fixed (헤더 숨겼으니 top:0) */
    #view-course {
      padding: 0;
    }
    #view-course.active {
      position: fixed;
      inset: 0;
      display: flex;
      flex-direction: column;
      background: #0a0a0a;
      animation: viewFadeIn var(--dur-slow) var(--ease-out-quint) both;
      z-index: 20;
    }

    .course-frame-wrap {
      position: relative;
      flex: 1 1 auto;
      min-height: 0;
      background: #0a0a0a;
      overflow: hidden;
    }

    .course-landing-frame {
      display: block;
      width: 100%;
      height: 100%;
      border: 0;
      background: #0a0a0a;
    }

    .course-frame-overlay {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: var(--sp-lg);
      background: #0a0a0a;
      color: #aaa;
      font-size: 14px;
      text-align: center;
      padding: var(--sp-3xl);
    }

    /* 하단 CTA bar — view-course 안의 footer 영역 */
    .course-cta-bar {
      flex: 0 0 auto;
      display: flex;
      align-items: center;
      gap: var(--sp-md);
      padding: var(--sp-md) var(--sp-xl);
      background: rgba(20,20,22,0.94);
      backdrop-filter: blur(20px) saturate(180%);
      -webkit-backdrop-filter: blur(20px) saturate(180%);
      border-top: 1px solid rgba(255,255,255,0.08);
      color: #fff;
      animation: courseCtaSlideUp 0.4s var(--ease-out-quint);
    }

    @keyframes courseCtaSlideUp {
      from { transform: translateY(100%); opacity: 0; }
      to { transform: translateY(0); opacity: 1; }
    }

    .course-cta-back {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: rgba(255,255,255,0.08);
      color: #fff;
      border: none;
      cursor: pointer;
      flex-shrink: 0;
      transition: background var(--dur-fast) ease;
    }
    .course-cta-back:hover {
      background: rgba(255,255,255,0.14);
    }

    .course-cta-info {
      flex: 1;
      min-width: 0;
    }

    .course-cta-title {
      font-size: 14px;
      font-weight: 600;
      color: #fff;
      letter-spacing: -0.3px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      margin-bottom: 2px;
    }

    /* 카운트다운 + 가격을 세로로 나란히 배치 (모바일에서도 가독성 유지) */
    .course-cta-meta {
      display: flex;
      flex-direction: column;
      gap: 2px;
    }

    .course-cta-countdown {
      display: inline-flex;
      align-items: center;
      gap: var(--sp-xs);
      font-size: 11.5px;
      color: rgba(255,255,255,0.65);
      letter-spacing: -0.2px;
    }
    .course-cta-countdown-label {
      font-weight: 500;
    }
    .course-cta-countdown-time {
      font-family: var(--font-en);
      font-weight: 700;
      color: #ff6b6b;
      letter-spacing: 0.5px;
      font-variant-numeric: tabular-nums;
    }

    .course-cta-price {
      font-family: var(--font-en);
      display: inline-flex;
      align-items: baseline;
      gap: var(--sp-xs);
      letter-spacing: -0.4px;
    }

    .course-cta-amount {
      font-size: 16px;
      font-weight: 800;
      color: #fff;
    }

    .course-cta-amount small {
      font-family: var(--font-kr);
      font-size: 11px;
      font-weight: 500;
      margin-left: 1px;
      opacity: 0.7;
    }

    .course-cta-original {
      font-size: 12.5px;
      color: rgba(255,255,255,0.45);
      text-decoration: line-through;
      font-weight: 400;
    }

    .course-cta-arrow {
      color: rgba(255,255,255,0.5);
      font-size: 12px;
    }

    /* 구독자 전용 배지 — fill 만 (accent gold), border 없음 */
    .course-cta-sub-badge {
      display: inline-block;
      margin-left: 6px;
      padding: 2px 8px;
      font-size: 10.5px;
      font-weight: 700;
      letter-spacing: 0.2px;
      color: #1d1d1f;
      background: #e8c878;
      border-radius: var(--radius-pill);
      vertical-align: middle;
    }

    .course-cta-owned {
      color: #34C759;
      font-weight: 700;
      font-size: 14px;
    }

    /* ========== 강의 자료 보기 모달 ========== */
    .course-modal-overlay.modal-overlay {
      background: rgba(0,0,0,0.78);
    }

    .modal.course-assets-modal {
      max-width: 460px;
      background: #14141a;
      color: #f4f1e8;
      border: 1px solid rgba(212,175,95,0.18);
      padding: var(--sp-3xl) var(--sp-2xl) var(--sp-2xl);
    }

    .course-assets-modal .modal-close {
      color: rgba(255,255,255,0.55);
    }
    .course-assets-modal .modal-close:hover {
      color: #fff;
    }

    .course-assets-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 10.5px;
      font-weight: 700;
      letter-spacing: 1.6px;
      color: #34C759;
      background: rgba(52,199,89,0.12);
      border: 1px solid rgba(52,199,89,0.3);
      padding: 4px var(--sp-sm);
      border-radius: var(--radius-pill);
      margin-bottom: var(--sp-lg);
      font-family: var(--font-en);
      text-transform: uppercase;
    }
    .course-assets-eyebrow svg { width: 12px; height: 12px; }

    .course-assets-title {
      font-size: 22px;
      font-weight: 700;
      letter-spacing: -0.8px;
      color: #fff;
      margin-bottom: 6px;
    }
    .course-assets-sub {
      font-size: 13.5px;
      color: rgba(244,241,232,0.65);
      margin-bottom: var(--sp-2xl);
    }
    .course-assets-empty {
      font-size: 13px;
      color: rgba(244,241,232,0.55);
      padding: var(--sp-xl) 0;
      text-align: center;
    }

    .course-assets-list {
      display: flex;
      flex-direction: column;
      gap: var(--sp-sm);
    }

    .course-asset-block {
      display: flex;
      align-items: center;
      gap: var(--sp-md);
      padding: var(--sp-lg);
      background: rgba(255,255,255,0.04);
      border: 1px solid rgba(212,175,95,0.2);
      border-radius: var(--radius-md);
    }
    .course-asset-block--telegram {
      background: linear-gradient(135deg, rgba(0,136,204,0.12), rgba(0,136,204,0.04));
      border-color: rgba(0,136,204,0.32);
    }
    .course-asset-block--muted {
      opacity: 0.6;
    }

    .course-asset-icon {
      width: 36px;
      height: 36px;
      flex-shrink: 0;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background: rgba(0,136,204,0.18);
      color: #4ab8ff;
      border-radius: 50%;
    }
    .course-asset-icon svg { width: 18px; height: 18px; }

    .course-asset-text { flex: 1; min-width: 0; }
    .course-asset-h3 {
      font-size: 14px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 2px;
    }
    .course-asset-desc {
      font-size: 12px;
      color: rgba(244,241,232,0.6);
    }

    .course-asset-cta {
      padding: var(--sp-sm) var(--sp-lg);
      font-size: 13px;
      font-weight: 700;
      color: #14141a;
      background: #4ab8ff;
      border-radius: var(--radius-pill);
      white-space: nowrap;
      text-decoration: none;
      transition: transform var(--dur-fast) var(--ease-spring-soft), background var(--dur-fast) ease;
    }
    .course-asset-cta:hover {
      background: #6cc7ff;
      transform: translateY(-1px);
    }

    .course-asset-section-title {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 1.4px;
      text-transform: uppercase;
      color: rgba(244,241,232,0.5);
      padding: var(--sp-md) var(--sp-xs) 4px;
      font-family: var(--font-en);
    }

    .course-asset-item {
      display: flex;
      align-items: center;
      gap: var(--sp-md);
      padding: var(--sp-md) var(--sp-lg);
      background: rgba(255,255,255,0.03);
      border: 1px solid rgba(255,255,255,0.06);
      border-radius: var(--radius-sm);
      color: #f4f1e8;
      text-decoration: none;
      cursor: pointer;
      transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease;
    }
    .course-asset-item:hover {
      background: rgba(255,255,255,0.06);
      border-color: rgba(212,175,95,0.28);
    }
    .course-asset-item-type {
      font-size: 16px;
    }
    .course-asset-item-title {
      flex: 1;
      font-size: 13.5px;
      font-weight: 500;
      color: #f4f1e8;
    }
    .course-asset-item-arrow {
      color: rgba(255,255,255,0.4);
      font-size: 14px;
    }

    .course-assets-close-btn {
      width: 100%;
      margin-top: var(--sp-2xl);
      padding: var(--sp-md);
      font-size: 14px;
      font-weight: 600;
      color: rgba(244,241,232,0.7);
      background: transparent;
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: var(--radius-pill);
      cursor: pointer;
      transition: background var(--dur-fast) ease;
    }
    .course-assets-close-btn:hover {
      background: rgba(255,255,255,0.05);
      color: #fff;
    }

    .course-cta-buy {
      padding: var(--sp-md) var(--sp-2xl);
      font-size: 14px;
      font-weight: 700;
      color: #1d1d1f;
      background: #fff;
      border: none;
      border-radius: var(--radius-pill);
      cursor: pointer;
      letter-spacing: -0.2px;
      transition: transform var(--dur-fast) var(--ease-spring-soft),
                  box-shadow var(--dur-normal) ease;
      box-shadow: 0 4px 16px rgba(255,255,255,0.18);
      white-space: nowrap;
    }

    .course-cta-buy:hover {
      transform: translateY(-1px);
      box-shadow: 0 6px 20px rgba(255,255,255,0.28);
    }

    .course-cta-buy:active {
      transform: scale(0.96);
    }

    /* 모바일 — CTA가 좁은 폭에 다 들어가도록 압축 */
    @media (max-width: 640px) {
      .course-cta-bar {
        padding: var(--sp-sm) var(--sp-md);
        gap: var(--sp-sm);
      }
      .course-cta-back {
        width: 32px;
        height: 32px;
        flex-shrink: 0;
      }
      .course-cta-info {
        flex: 1 1 0;
        min-width: 0;
        overflow: hidden;
      }
      .course-cta-title {
        font-size: 12px;
        margin-bottom: 1px;
      }
      .course-cta-meta {
        gap: 1px;
      }
      .course-cta-countdown {
        font-size: 10px;
        gap: 4px;
      }
      .course-cta-countdown-label {
        display: none; /* 라벨 숨김 — 시간만 노출 */
      }
      .course-cta-countdown-time {
        font-size: 11px;
        letter-spacing: 0;
      }
      .course-cta-price {
        gap: 4px;
        flex-wrap: wrap;
      }
      .course-cta-amount {
        font-size: 13px;
      }
      .course-cta-amount small {
        font-size: 10px;
      }
      .course-cta-original {
        font-size: 10.5px;
      }
      .course-cta-arrow {
        font-size: 10px;
      }
      .course-cta-buy {
        padding: var(--sp-sm) var(--sp-md);
        font-size: 12.5px;
        flex-shrink: 0;
      }
    }

    /* 매우 좁은 폭(360px 이하) — 추가 압축 */
    @media (max-width: 360px) {
      .course-cta-bar { gap: 6px; padding: 6px 8px; }
      .course-cta-back { width: 28px; height: 28px; }
      .course-cta-title { font-size: 11px; }
      .course-cta-buy { padding: 6px 10px; font-size: 11.5px; }
    }

    /* ========== 강의실 view (구매자 + 어드민 미리보기) ========== */
    /* 강의실은 항상 다크 — 자체 토큰 스코프 정의 */
    #view-classroom {
      --cr-bg-page:        #14141a;
      --cr-bg-sidebar:     #1a1a20;
      --cr-bg-main:        #0f0f14;
      --cr-bg-stage:       #000;
      --cr-bg-header:      rgba(0,0,0,0.4);
      --cr-fg:             #f4f1e8;
      --cr-fg-strong:      #fff;
      --cr-fg-muted:       rgba(244,241,232,0.72);
      --cr-fg-dim:         rgba(244,241,232,0.5);
      --cr-fg-faint:       rgba(244,241,232,0.35);
      --cr-divider:        rgba(244,241,232,0.06);
      --cr-divider-strong: rgba(244,241,232,0.12);
      --cr-surface:        rgba(244,241,232,0.04);
      --cr-surface-hover:  rgba(244,241,232,0.08);
      --cr-accent:         #e8c878;
      --cr-accent-strong:  #f0d68a;
      --cr-accent-fg:      #1d1d1f;
      --cr-accent-bg:      rgba(232,200,120,0.14);
      --cr-warn-fg:        #ff9500;
      --cr-warn-bg:        rgba(255,149,0,0.15);
      --cr-telegram-1:     #2AABEE;
      --cr-telegram-2:     #229ED9;
      --cr-telegram-shadow: rgba(34,158,217,0.32);
      --cr-telegram-shadow-strong: rgba(34,158,217,0.5);
    }

    body.classroom-active { overflow: hidden; }
    body.classroom-active .header { display: none; }
    body.classroom-active .footer { display: none; }
    body.classroom-active .scroll-top-btn { display: none !important; }

    #view-classroom { padding: 0; }
    #view-classroom.active {
      position: fixed;
      inset: 0;
      display: flex;
      flex-direction: column;
      background: var(--cr-bg-page);
      color: var(--cr-fg);
      z-index: 20;
      animation: viewFadeIn var(--dur-slow) var(--ease-out-quint) both;
    }

    /* 헤더 — fill (반투명) + 하단 divider (1px) 만, 컨테이너 border 없음 */
    .classroom-header {
      display: flex;
      align-items: center;
      gap: var(--sp-md);
      padding: var(--sp-md) var(--sp-xl);
      background: var(--cr-bg-header);
      border-bottom: 1px solid var(--cr-divider-strong);
      backdrop-filter: blur(12px);
      flex-shrink: 0;
    }
    /* 뒤로가기 — hover 시에만 fill */
    .classroom-back {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: var(--sp-sm) var(--sp-md);
      font-size: 13px;
      color: var(--cr-fg);
      background: transparent;
      border: none;
      border-radius: var(--radius-pill);
      cursor: pointer;
      transition: background 0.15s;
    }
    .classroom-back:hover { background: var(--cr-surface-hover); }
    .classroom-title {
      flex: 1;
      font-size: 14px;
      font-weight: 600;
      letter-spacing: -0.3px;
      color: var(--cr-fg-strong);
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    /* 미리보기 배지 — fill 만 (border 없음) */
    .classroom-preview-badge {
      padding: 4px var(--sp-sm);
      font-size: 10.5px;
      font-weight: 700;
      color: var(--cr-warn-fg);
      background: var(--cr-warn-bg);
      border-radius: var(--radius-pill);
    }

    .classroom-layout {
      flex: 1;
      display: grid;
      grid-template-columns: 280px 1fr;
      min-height: 0;
    }
    @media (max-width: 768px) {
      .classroom-layout { grid-template-columns: 1fr; }
    }

    /* 사이드바 — fill + 우측 1px divider, 컨테이너 border 없음 */
    .classroom-sidebar {
      background: var(--cr-bg-sidebar);
      border-right: 1px solid var(--cr-divider);
      overflow-y: auto;
      padding: var(--sp-lg) var(--sp-md);
      display: flex;
      flex-direction: column;
      gap: var(--sp-lg);
    }
    @media (max-width: 768px) {
      .classroom-sidebar {
        max-height: 240px;
        border-right: none;
        border-bottom: 1px solid var(--cr-divider);
      }
    }

    .classroom-sidebar-section {
      display: flex;
      flex-direction: column;
    }
    .classroom-sidebar-title {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.2px;
      color: var(--cr-fg-dim);
      padding: 0 var(--sp-md);
      margin-bottom: var(--sp-sm);
    }

    /* 텔레그램 입장 버튼 — 텔레그램 브랜드 그라데이션 fill, border 없음 */
    .classroom-telegram-btn {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      width: calc(100% - 2 * var(--sp-md));
      margin: 0 var(--sp-md);
      padding: var(--sp-sm) var(--sp-md);
      font-size: 13px;
      font-weight: 600;
      color: var(--cr-fg-strong);
      background: linear-gradient(135deg, var(--cr-telegram-1) 0%, var(--cr-telegram-2) 100%);
      border: none;
      border-radius: var(--radius-pill);
      text-decoration: none;
      justify-content: center;
      box-shadow: 0 4px 12px var(--cr-telegram-shadow);
      transition: transform 0.15s var(--ease-spring-soft), box-shadow 0.15s ease;
    }
    .classroom-telegram-btn:hover {
      transform: translateY(-1px);
      box-shadow: 0 6px 18px var(--cr-telegram-shadow-strong);
    }

    .classroom-asset-nav {
      display: flex;
      flex-direction: column;
      gap: var(--sp-lg);
    }
    .classroom-asset-group {
      display: flex;
      flex-direction: column;
      gap: 2px;
    }
    /* 자료 항목 — hover/active 시에만 fill, border 없음 */
    .classroom-asset-item {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
      padding: var(--sp-sm) var(--sp-md);
      font-size: 13px;
      text-align: left;
      color: var(--cr-fg-muted);
      background: transparent;
      border: none;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: background 0.15s, color 0.15s;
    }
    .classroom-asset-item:hover {
      background: var(--cr-surface-hover);
      color: var(--cr-fg-strong);
    }
    .classroom-asset-item.active {
      background: var(--cr-accent-bg);
      color: var(--cr-accent);
      font-weight: 600;
    }
    .classroom-asset-name {
      flex: 1;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .classroom-no-assets {
      padding: var(--sp-md);
      font-size: 12.5px;
      color: var(--cr-fg-dim);
    }

    .classroom-main {
      position: relative;
      background: var(--cr-bg-main);
      overflow: hidden;
    }

    .classroom-empty {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: var(--sp-sm);
      color: var(--cr-fg-dim);
      text-align: center;
      padding: var(--sp-2xl);
    }
    .classroom-empty h3 { font-size: 18px; color: var(--cr-fg); font-weight: 600; }
    .classroom-empty p { font-size: 13.5px; }

    /* PDF iframe — 외부 컨테이너 라서 컨테이너 fill (흰 배경 PDF 위) 만, border 없음 */
    .classroom-pdf-frame {
      width: 100%;
      height: 100%;
      border: 0;
      background: var(--color-surface);
    }

    /* 강의 영상 플레이어 — fill 위주, 컨테이너 border 금지 */
    .classroom-video-box {
      width: 100%;
      height: 100%;
      display: flex;
      flex-direction: column;
      background: var(--cr-bg-main);
      overflow-y: auto;
    }
    /* 비디오 무대 — fill 만 (하단 divider 는 레이아웃용 1px) */
    .classroom-video-stage {
      width: 100%;
      background: var(--cr-bg-stage);
      display: flex;
      justify-content: center;
      border-bottom: 1px solid var(--cr-divider);
    }
    .classroom-video-player {
      width: 100%;
      max-height: min(70vh, calc(100vw * 9 / 16));
      background: var(--cr-bg-stage);
      outline: none;
      display: block;
    }
    .classroom-video-meta {
      max-width: 960px;
      width: 100%;
      margin: 0 auto;
      padding: var(--sp-xl) var(--sp-xl) var(--sp-3xl);
      display: flex;
      flex-direction: column;
      gap: var(--sp-xl);
    }
    .classroom-video-meta-head {
      display: flex;
      flex-direction: column;
      gap: var(--sp-sm);
    }
    .classroom-video-eyebrow {
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.6px;
      color: var(--cr-fg-dim);
    }
    .classroom-video-eyebrow:empty { display: none; }
    .classroom-video-title {
      font-size: 22px;
      font-weight: 700;
      color: var(--cr-fg);
      letter-spacing: -0.4px;
      margin: 0;
      line-height: 1.35;
    }
    .classroom-video-description {
      font-size: 14.5px;
      line-height: 1.75;
      color: var(--cr-fg-muted);
      margin: 0;
      white-space: pre-wrap;
    }
    .classroom-video-description:empty::before {
      content: '설명 없음. 어드민에서 설명을 추가하거나 영상 분석을 실행하세요.';
      color: var(--cr-fg-faint);
      font-style: italic;
    }
    .classroom-video-nav {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: var(--sp-sm);
    }
    /* 이전/다음 버튼 — fill 만 사용, border 없음 (hover 시 fill 강조) */
    .classroom-video-nav-btn {
      display: flex;
      align-items: center;
      gap: var(--sp-sm);
      padding: var(--sp-md) var(--sp-lg);
      background: var(--cr-surface);
      border: none;
      border-radius: var(--radius-md);
      color: var(--cr-fg);
      cursor: pointer;
      transition: background 0.15s;
      text-align: left;
      min-height: 64px;
    }
    .classroom-video-nav-btn:hover:not(:disabled) {
      background: var(--cr-surface-hover);
    }
    .classroom-video-nav-btn:disabled {
      opacity: 0.35;
      cursor: not-allowed;
    }
    .classroom-video-nav-btn--next {
      justify-content: flex-end;
      text-align: right;
    }
    .classroom-video-nav-label {
      display: flex;
      flex-direction: column;
      gap: 2px;
      min-width: 0;
      flex: 1;
    }
    .classroom-video-nav-btn--next .classroom-video-nav-label { align-items: flex-end; }
    .classroom-video-nav-cap {
      font-size: 11px;
      letter-spacing: 0.4px;
      color: var(--cr-fg-dim);
    }
    .classroom-video-nav-title {
      font-size: 13.5px;
      font-weight: 600;
      color: var(--cr-fg);
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      max-width: 100%;
    }
    /* 강의 회차 리스트 — 상단 1px divider 는 섹션 구분용 */
    .classroom-video-list {
      display: flex;
      flex-direction: column;
      gap: 6px;
      border-top: 1px solid var(--cr-divider);
      padding-top: var(--sp-xl);
    }
    .classroom-video-list-title {
      font-size: 13px;
      font-weight: 600;
      letter-spacing: 0.4px;
      color: var(--cr-fg-dim);
      margin: 0 0 var(--sp-sm);
    }
    /* 회차 항목 — 평소 transparent, hover/active 모두 fill 만 사용 (border 없음) */
    .classroom-video-list-item {
      display: flex;
      align-items: center;
      gap: var(--sp-md);
      padding: var(--sp-md);
      background: transparent;
      border: none;
      border-radius: var(--radius-sm);
      color: var(--cr-fg);
      cursor: pointer;
      text-align: left;
      transition: background 0.12s;
    }
    .classroom-video-list-item:hover {
      background: var(--cr-surface-hover);
    }
    .classroom-video-list-item.active {
      background: var(--cr-accent-bg);
    }
    /* 회차 번호 배지 — 원형 fill 만 */
    .classroom-video-list-num {
      flex-shrink: 0;
      min-width: 36px;
      height: 28px;
      padding: 0 8px;
      border-radius: var(--radius-pill);
      background: var(--cr-surface);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 11.5px;
      font-weight: 700;
      color: var(--cr-fg-muted);
      white-space: nowrap;
    }
    .classroom-video-list-item.active .classroom-video-list-num {
      background: var(--cr-accent);
      color: var(--cr-accent-fg);
    }
    .classroom-video-list-item.active .classroom-video-list-name {
      color: var(--cr-accent);
    }
    .classroom-video-list-body {
      display: flex;
      flex-direction: column;
      gap: 2px;
      min-width: 0;
      flex: 1;
    }
    .classroom-video-list-name {
      font-size: 13.5px;
      font-weight: 600;
      color: var(--cr-fg);
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    .classroom-video-list-meta {
      font-size: 11.5px;
      color: var(--cr-fg-dim);
    }
    @media (max-width: 768px) {
      .classroom-video-meta { padding: var(--sp-md) var(--sp-md) var(--sp-2xl); gap: var(--sp-lg); }
      .classroom-video-title { font-size: 17px; }
      .classroom-video-description { font-size: 13.5px; }
      .classroom-video-player { max-height: 56vh; }
      .classroom-video-nav { grid-template-columns: 1fr; }
      .classroom-video-nav-btn { min-height: 56px; }
    }

    .classroom-post-body {
      max-width: 760px;
      margin: 0 auto;
      padding: var(--sp-4xl) var(--sp-2xl);
      font-size: 16px;
      line-height: 1.8;
      color: var(--cr-fg-muted);
      overflow-y: auto;
      height: 100%;
      box-sizing: border-box;
    }
    .classroom-post-title {
      font-size: 28px;
      font-weight: 800;
      letter-spacing: -1px;
      color: var(--cr-fg-strong);
      margin-bottom: var(--sp-2xl);
    }
    .classroom-post-body h2 {
      font-size: 20px;
      font-weight: 700;
      color: var(--cr-fg-strong);
      margin-top: var(--sp-2xl);
      margin-bottom: var(--sp-md);
    }
    .classroom-post-body p {
      margin-bottom: var(--sp-md);
    }
    .classroom-post-body a {
      color: var(--cr-accent);
      text-decoration: underline;
    }
    .classroom-post-body img {
      max-width: 100%;
      border-radius: var(--radius-md);
      margin: var(--sp-md) 0;
    }

    .classroom-link-box {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: var(--sp-lg);
      padding: var(--sp-2xl);
      text-align: center;
    }
    .classroom-link-box h2 {
      font-size: 22px;
      font-weight: 700;
      color: var(--cr-fg-strong);
    }
    /* 외부 링크 CTA — accent fill 만 (border 없음) */
    .classroom-link-cta {
      display: inline-flex;
      align-items: center;
      padding: var(--sp-md) var(--sp-2xl);
      font-size: 14px;
      font-weight: 700;
      color: var(--cr-accent-fg);
      background: var(--cr-accent);
      border: none;
      border-radius: var(--radius-pill);
      text-decoration: none;
      transition: transform 0.15s, background 0.15s;
    }
    .classroom-link-cta:hover {
      background: var(--cr-accent-strong);
      transform: translateY(-1px);
    }