/* ==========================================================================
   나만 알고 싶은 AI 교과서 — app.css
   프리미엄 에듀케이션 브랜드 리디자인
   딥네이비~인디고 다크 히어로 / 아이보리·화이트 라이트 콘텐츠
   포인트: 골드(#D4A843) + 인디고(#4F46E5)
   ========================================================================== */

:root {
  /* ---- Brand palette ---- */
  --color-navy: var(--brand-strong, #0E2A50);
  --color-navy-soft: #131B2E;
  --color-indigo: var(--brand, #143A6B);
  --color-indigo-dark: var(--brand-strong, #0E2A50);
  --color-indigo-light: var(--brand-tint, #EAF0FA);
  --color-gold: var(--accent, #E2431F);
  --color-gold-light: var(--accent-tint, #FDECE7);
  --color-gold-dark: var(--accent-strong, #C6371A);

  /* app.js/render.js가 참조하는 기존 변수명은 유지하되 새 팔레트로 매핑 */
  --color-primary: var(--color-indigo);
  --color-primary-dark: var(--color-indigo-dark);
  --color-primary-light: var(--color-indigo-light);
  --color-accent: var(--color-gold);
  --color-accent-light: var(--color-gold-light);

  --color-ink: var(--text-strong, #0F172A);
  --color-ink-soft: var(--text, #334155);
  --color-muted: var(--text-muted, #64748B);
  --color-bg: var(--surface, #F7F8FA);          /* ivory→cool-gray, onae-tokens 정본 */
  --color-surface: var(--bg, #FFFFFF);
  --color-surface-alt: var(--surface-2, #EFF1F5);
  --color-border: var(--border, #E2E5EB);
  --color-border-strong: rgba(23, 27, 43, 0.14);
  --color-success: var(--success, #0E7A50);
  --color-danger: var(--danger, #DC2626);

  /* ---- Typography ---- */
  --font-sans: "Pretendard", "Apple SD Gothic Neo", "Malgun Gothic", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-display: "Noto Serif KR", "Pretendard", serif;

  /* ---- Radius ---- */
  --radius-xl: 24px;
  --radius-lg: 20px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --radius-xs: 8px;

  /* ---- Layered shadows ---- */
  --shadow-sm: 0 1px 2px rgba(11, 18, 32, 0.06);
  --shadow-md: 0 1px 2px rgba(11, 18, 32, 0.06), 0 8px 24px rgba(11, 18, 32, 0.08);
  --shadow-lg: 0 1px 2px rgba(11, 18, 32, 0.08), 0 16px 40px rgba(11, 18, 32, 0.14);
  --shadow-gold: 0 1px 2px rgba(212, 168, 67, 0.15), 0 8px 24px rgba(212, 168, 67, 0.22);

  /* ---- Motion ---- */
  --ease-premium: cubic-bezier(0.2, 0.8, 0.2, 1);
  --dur-fast: 0.15s;
  --dur-base: 0.2s;
  --dur-slow: 0.4s;

  --container-width: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-ink);
  background: var(--color-bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; }
ul { list-style: none; margin: 0; padding: 0; }
h1, h2, h3, h4, p { margin: 0; }
h1, h2, h3, h4 { font-family: var(--font-display); letter-spacing: -0.01em; }

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-indigo);
  color: #fff;
  padding: 0.75rem 1rem;
  z-index: 200;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; }

/* ---------- Global interactive affordances ---------- */
@media (prefers-reduced-motion: no-preference) {
  a[data-nav], button, .btn, .book-card, .chapter-card, .quicklink-card,
  .tab-btn, .accordion-header, .gallery-item, .book3d, .video-thumb-btn,
  .share-btn, .role-switcher-btn, .modal-close, .modal-tab, .news-item.is-clickable {
    transition: transform var(--dur-base) var(--ease-premium),
                box-shadow var(--dur-base) var(--ease-premium),
                border-color var(--dur-base) var(--ease-premium),
                background var(--dur-base) var(--ease-premium),
                color var(--dur-base) var(--ease-premium),
                filter var(--dur-base) var(--ease-premium);
  }
}
@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;
  }
}

/* focus-visible ring: 일관된 접근성 포커스 표시 */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible,
[tabindex]:focus-visible {
  outline: 2.5px solid var(--color-indigo);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}

/* 클릭 가능 요소 공통 어포던스 */
a[data-nav], .btn, .tab-btn, .accordion-header, .quicklink-card, .gallery-item,
.chapter-card, .book-card, .video-thumb-btn, .share-btn, .modal-tab, .role-switcher-btn {
  cursor: pointer;
}
.btn:active, .tab-btn:active, .accordion-header:active, .quicklink-card:active,
.gallery-item:active, .chapter-card:active, .book-card:active, .modal-tab:active,
.role-switcher-btn:active, .share-btn:active {
  transform: scale(0.98);
}

/* 정적 정보 박스: hover 반응 없음을 명확히 구분 */
.chapter-block, .sources-box, .prompt-example, .tip-box, .activity-card.static,
.detail-summary, .goal-list, .chip-group {
  cursor: default;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(251, 250, 247, 0.86);
  backdrop-filter: blur(10px) saturate(140%);
  -webkit-backdrop-filter: blur(10px) saturate(140%);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--dur-base) var(--ease-premium),
              background var(--dur-base) var(--ease-premium);
}
.site-header.is-scrolled {
  box-shadow: var(--shadow-md);
  background: rgba(251, 250, 247, 0.94);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: var(--header-h, 64px);          /* onae 공통헤더 표준: 데스크톱 64px */
  flex-wrap: wrap;
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
  transition: min-height var(--dur-base) var(--ease-premium);
}
.site-header.is-scrolled .header-inner { min-height: 60px; }

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  flex-shrink: 0;
}
.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-xs);
  background: linear-gradient(135deg, var(--color-indigo), var(--color-navy));
  color: #fff;
  font-size: 0.95rem;
  letter-spacing: 0.02em;
  box-shadow: var(--shadow-sm);
}
.logo-text {
  font-family: var(--font-display);
  font-size: 0.95rem;
  line-height: 1.25;
  color: var(--color-ink);
  font-weight: 700;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: transparent;
  border: none;
  padding: 0.5rem;
  margin-left: auto;
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-ink);
  border-radius: 2px;
}

.main-nav {
  display: flex;
  gap: 0.1rem;
  flex-wrap: wrap;
  margin-left: 0.25rem;
}
.main-nav a {
  padding: 0.45rem 0.7rem;
  border-radius: 999px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-ink-soft);
  white-space: nowrap;
  position: relative;
}
.main-nav a:hover { background: var(--color-indigo-light); color: var(--color-indigo-dark); }
.main-nav a.active { background: var(--color-indigo); color: #fff; box-shadow: var(--shadow-sm); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  margin-left: auto;
  position: relative;
}

/* 테마 · 언어 유틸리티 컨트롤: 아이콘 중심으로 압축된 한 덩어리로 묶는다 */
.chrome-controls-mount {
  display: inline-flex;
  align-items: center;
  gap: 0.15rem;
  padding: 0.15rem;
  border-radius: 999px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
}
.chrome-controls-mount:empty { display: none; }
.chrome-controls-mount .theme-switcher-btn,
.chrome-controls-mount .lang-switcher-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 0.35rem 0.55rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-ink-soft);
  box-shadow: none;
  cursor: pointer;
}
.chrome-controls-mount .theme-switcher-btn:hover,
.chrome-controls-mount .lang-switcher-btn:hover {
  background: var(--color-surface);
  color: var(--color-indigo);
}
/* 좁은 폭에서는 텍스트 라벨을 숨겨 아이콘만 남긴다 (더 압축) */
@media (max-width: 1140px) {
  .chrome-controls-mount .theme-switcher-label,
  .chrome-controls-mount .lang-switcher-label { display: none; }
}

/* 현재 보기 상태를 나타내는 중립 상태 칩 (강조하지 않음) */
.role-badge {
  font-size: 0.74rem;
  font-weight: 600;
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  color: var(--color-ink-soft);
  white-space: nowrap;
}
.role-badge[data-role="premium"] { background: var(--color-gold-light); border-color: transparent; color: var(--color-gold-dark); }
.role-badge[data-role="admin"] { background: var(--color-navy); border-color: transparent; color: #fff; }

.role-switcher { position: relative; }
.role-switcher-btn {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0.5rem 0.85rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-ink-soft);
  box-shadow: var(--shadow-sm);
}
.role-switcher-btn:hover { border-color: var(--color-indigo); color: var(--color-indigo); box-shadow: var(--shadow-md); transform: translateY(-2px); }

/* 주 행동(로그인 · 체험): 솔리드 버튼으로 시선을 끈다.
   ai-theme.css / theme-light / theme-cute가 .role-switcher-btn을 !important로
   재정의하므로, 헤더 스코프의 높은 특이도(0-3-0)로 확실히 이긴다. */
.header-actions .role-switcher .role-switcher-btn--primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.9rem;
  background: linear-gradient(135deg, var(--color-indigo), var(--color-navy)) !important;
  border: 1px solid transparent !important;
  color: #fff !important;
  box-shadow: var(--shadow-sm);
}
.header-actions .role-switcher .role-switcher-btn--primary:hover {
  border-color: transparent !important;
  color: #fff !important;
  filter: brightness(1.06);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.role-switcher-icon { font-size: 0.95rem; line-height: 1; }
.role-switcher-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  line-height: 1.1;
}
.role-switcher-title { font-size: 0.84rem; font-weight: 700; }
.role-switcher-sub { font-size: 0.66rem; font-weight: 500; opacity: 0.82; letter-spacing: 0.01em; }
.role-switcher-caret { font-size: 0.7rem; opacity: 0.9; margin-left: 0.05rem; }

.role-dropdown {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 216px;
  padding: 0.4rem;
  z-index: 150;
}
.role-dropdown-caption {
  padding: 0.45rem 0.75rem 0.5rem;
  font-size: 0.72rem;
  font-weight: 600;
  /* 색상은 상속 + 투명도로 처리해 다크/라이트/큐트 어느 테마에서도 대비를 유지한다 */
  color: inherit;
  opacity: 0.62;
  letter-spacing: 0.01em;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 0.3rem;
}
.role-dropdown li button {
  display: block;
  width: 100%;
  text-align: left;
  background: transparent;
  border: none;
  padding: 0.6rem 0.75rem;
  border-radius: var(--radius-xs);
  font-size: 0.86rem;
  color: var(--color-ink);
  cursor: pointer;
}
.role-dropdown li button:hover { background: var(--color-bg); }

/* ---------- Main / Layout ---------- */
.app-main {
  min-height: 60vh;
  padding-top: 2rem;
  padding-bottom: 4rem;
}
.app-main:focus { outline: none; }

/* 뷰 전환 페이드-인 (motion.js가 부착) */
.app-main.view-fade-in {
  animation: viewFadeIn var(--dur-slow) var(--ease-premium);
}
@keyframes viewFadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 스크롤 리빌 (motion.js가 .reveal 부착 + IntersectionObserver로 .is-visible 토글) */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s var(--ease-premium), transform 0.6s var(--ease-premium);
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

.loading-spinner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 5rem 0;
  color: var(--color-muted);
}
.spinner {
  width: 36px;
  height: 36px;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-indigo);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.error-box {
  background: #FEF2F2;
  border: 1px solid #FECACA;
  color: #991B1B;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  text-align: center;
}

/* ---------- Hero (다크 프리미엄) ---------- */
.hero {
  position: relative;
  background: linear-gradient(160deg, var(--color-navy) 0%, #16203A 45%, var(--color-indigo-dark) 100%);
  color: #fff;
  border-radius: var(--radius-xl);
  padding: 4rem 2.5rem;
  margin-bottom: 3.5rem;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  isolation: isolate;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}
.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(10px);
  opacity: 0.55;
}
.hero-orb-1 {
  width: 420px; height: 420px;
  top: -140px; left: -100px;
  background: radial-gradient(circle, rgba(79,70,229,0.55), transparent 70%);
  animation: floatOrb1 18s ease-in-out infinite;
}
.hero-orb-2 {
  width: 380px; height: 380px;
  bottom: -160px; right: -80px;
  background: radial-gradient(circle, rgba(212,168,67,0.35), transparent 70%);
  animation: floatOrb2 22s ease-in-out infinite;
}
.hero-orb-3 {
  width: 300px; height: 300px;
  top: 40%; left: 55%;
  background: radial-gradient(circle, rgba(99,102,241,0.3), transparent 70%);
  animation: floatOrb3 26s ease-in-out infinite;
}
@keyframes floatOrb1 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, 30px) scale(1.08); }
}
@keyframes floatOrb2 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-30px, -40px) scale(1.05); }
}
@keyframes floatOrb3 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-20px, 25px) scale(0.95); }
}
@media (prefers-reduced-motion: reduce) {
  .hero-orb { animation: none; }
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 2.5rem;
  flex-wrap: wrap;
}
.hero-copy { flex: 1 1 420px; min-width: 280px; }
.hero-eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-gold);
  background: rgba(212, 168, 67, 0.14);
  border: 1px solid rgba(212, 168, 67, 0.35);
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  margin-bottom: 1.1rem;
}
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.9rem);
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.35;
}
.hero p {
  font-size: 1.05rem;
  opacity: 0.86;
  max-width: 560px;
  line-height: 1.8;
}
.hero .hero-cta {
  margin-top: 1.85rem;
  display: flex;
  gap: 0.85rem;
  flex-wrap: wrap;
}

.hero-stats {
  margin-top: 2.4rem;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.9rem;
  max-width: 560px;
}
.stat-badge {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: var(--radius-md);
  padding: 0.9rem 0.7rem;
  text-align: center;
  backdrop-filter: blur(4px);
}
.stat-num {
  display: block;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-gold);
  margin-bottom: 0.2rem;
}
.stat-label {
  display: block;
  font-size: 0.72rem;
  color: rgba(255,255,255,0.78);
  line-height: 1.4;
}

.hero-visual {
  flex: 1 1 280px;
  min-width: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-stack {
  position: relative;
  width: 220px;
  height: 260px;
  perspective: 1400px;
}
.hero-stack-item {
  position: absolute;
  inset: 0;
  transition: transform var(--dur-slow) var(--ease-premium);
}
.hero-stack-item .book3d { width: 150px; margin: 0 auto; }
.hero-stack-item-0 { transform: translateX(-46px) rotate(-9deg) translateY(14px); z-index: 1; }
.hero-stack-item-1 { transform: translateX(0) rotate(0deg); z-index: 2; }
.hero-stack-item-2 { transform: translateX(46px) rotate(9deg) translateY(14px); z-index: 1; }
.hero-stack:hover .hero-stack-item-0 { transform: translateX(-58px) rotate(-13deg) translateY(4px); }
.hero-stack:hover .hero-stack-item-2 { transform: translateX(58px) rotate(13deg) translateY(4px); }

.banner {
  background: var(--color-gold-light);
  border: 1px solid #EAD9AE;
  color: var(--color-gold-dark);
  padding: 0.9rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 700;
  text-align: center;
  margin-bottom: 2rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.75rem 1.4rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.92rem;
  border: 1px solid transparent;
  position: relative;
}
.btn-primary {
  background: linear-gradient(135deg, #ffffff, #f2f0ff);
  color: var(--color-indigo-dark);
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); filter: brightness(1.03); }
.btn-outline {
  background: transparent;
  border: 1.5px solid rgba(255,255,255,0.55);
  color: #fff;
}
.btn-outline:hover { background: rgba(255,255,255,0.12); border-color: #fff; transform: translateY(-3px); }
.btn-solid {
  background: linear-gradient(135deg, var(--color-indigo), var(--color-indigo-dark));
  color: #fff;
  box-shadow: var(--shadow-sm);
}
.btn-solid:hover { filter: brightness(1.12); box-shadow: var(--shadow-md); transform: translateY(-3px); }
.btn-ghost {
  background: var(--color-surface);
  color: var(--color-ink-soft);
  border: 1px solid var(--color-border);
}
.btn-ghost:hover { border-color: var(--color-indigo); color: var(--color-indigo); transform: translateY(-3px); box-shadow: var(--shadow-sm); }
.btn-sm { padding: 0.5rem 0.9rem; font-size: 0.8rem; }

/* ---------- Section headings ---------- */
.section {
  margin-bottom: 3.75rem;
}
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}
.section-head h2 {
  font-size: 1.55rem;
  font-weight: 700;
  color: var(--color-ink);
}
.section-head .section-sub {
  color: var(--color-muted);
  font-size: 0.9rem;
}
a.section-sub:hover { color: var(--color-indigo); }

/* ---------- Card grid ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 1.4rem;
}

.book-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  border: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
}
.book-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(79, 70, 229, 0.3);
}

.book-cover {
  aspect-ratio: 3 / 4;
  background: var(--color-indigo-light);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}
.book-cover img { width: 100%; height: 100%; object-fit: cover; }
.book-cover .cover-fallback {
  font-weight: 700;
  color: var(--color-indigo-dark);
  font-size: 1.1rem;
  padding: 1rem;
  text-align: center;
}

/* ---------- 3D 북커버 컴포넌트 ---------- */
.book3d {
  position: relative;
  perspective: 900px;
  padding: 4px 4px 10px 4px;
}
.book3d .book-cover {
  position: relative;
  border-radius: var(--radius-sm) var(--radius-xs) var(--radius-xs) var(--radius-sm);
  transform: rotateY(18deg) rotateX(1deg);
  transform-style: preserve-3d;
  transition: transform var(--dur-slow) var(--ease-premium), box-shadow var(--dur-slow) var(--ease-premium);
  box-shadow:
    0 1px 2px rgba(11,18,32,0.12),
    6px 10px 18px rgba(11,18,32,0.18),
    12px 22px 34px rgba(11,18,32,0.16);
}
.book3d .book-cover::before {
  /* 책등(spine) */
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 10px;
  background: linear-gradient(90deg, rgba(0,0,0,0.35), rgba(0,0,0,0));
  transform: translateX(-9px) rotateY(-90deg);
  transform-origin: right center;
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}
.book3d-shadow {
  position: absolute;
  left: 10%;
  right: 10%;
  bottom: -6px;
  height: 16px;
  background: radial-gradient(ellipse at center, rgba(11,18,32,0.32), transparent 72%);
  filter: blur(2px);
  transition: opacity var(--dur-slow) var(--ease-premium), transform var(--dur-slow) var(--ease-premium);
}
.book3d:hover .book-cover,
a:hover > .book3d .book-cover,
.book-card:hover .book3d .book-cover {
  transform: rotateY(0deg) rotateX(0deg) translateY(-6px);
  box-shadow:
    0 1px 2px rgba(11,18,32,0.1),
    0 8px 24px rgba(11,18,32,0.16),
    0 20px 40px rgba(11,18,32,0.18);
}
.book3d:hover .book3d-shadow,
.book-card:hover .book3d .book3d-shadow {
  transform: scaleX(1.08);
  opacity: 0.7;
}
@media (prefers-reduced-motion: reduce) {
  .book3d .book-cover { transition: none; }
}

.book-card-body {
  padding: 1.1rem 1.2rem 1.3rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  flex: 1;
}
.book-card-title {
  font-weight: 700;
  font-size: 1rem;
  line-height: 1.4;
}
.book-card-title:hover { color: var(--color-indigo); }
.book-card-audience {
  font-size: 0.8rem;
  color: var(--color-muted);
}
.book-card-foot {
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

/* ---------- Tier badge ---------- */
.tier-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.72rem;
  font-weight: 800;
  padding: 0.28rem 0.65rem;
  border-radius: 999px;
  letter-spacing: 0.02em;
}
.tier-badge.tier-free { background: #DCFCE7; color: #166534; }
.tier-badge.tier-premium { background: var(--color-gold-light); color: var(--color-gold-dark); cursor: help; }
.tier-badge.tier-locked { background: #F1F0EA; color: var(--color-ink-soft); }
.tier-badge.tier-member { background: var(--color-indigo-light); color: var(--color-indigo-dark); }

.lock-note {
  font-size: 0.72rem;
  color: var(--color-muted);
}

/* ---------- Tabs ---------- */
.tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.9rem;
}
.tab-btn {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 0.6rem 1.15rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.88rem;
  color: var(--color-ink-soft);
}
.tab-btn:hover { border-color: var(--color-indigo); color: var(--color-indigo); transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.tab-btn.active { background: var(--color-indigo); color: #fff; border-color: var(--color-indigo); box-shadow: var(--shadow-sm); }

/* ---------- Accordion ---------- */
.accordion-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.accordion-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  background: transparent;
  border: none;
  padding: 1.15rem 1.4rem;
  font-weight: 800;
  font-size: 1.02rem;
  text-align: left;
}
.accordion-header:hover { background: var(--color-surface-alt); }
.accordion-header .chevron { transition: transform var(--dur-base) var(--ease-premium); color: var(--color-muted); }
.accordion-item.open .accordion-header .chevron { transform: rotate(180deg); color: var(--color-indigo); }
.accordion-body {
  padding: 0 1.4rem 1.4rem;
  display: none;
}
.accordion-item.open .accordion-body { display: block; animation: accordionIn 0.25s var(--ease-premium); }
@keyframes accordionIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: translateY(0); } }

.chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0.6rem 0 1rem;
}
.chip {
  background: var(--color-indigo-light);
  color: var(--color-indigo-dark);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
}
.chip.tool-chip { background: #EDE9FE; color: #5B21B6; }
.chip.subject-chip { background: var(--color-gold-light); color: var(--color-gold-dark); }

.goal-list {
  margin: 0.5rem 0 1rem;
  padding-left: 1.2rem;
  list-style: disc;
  color: var(--color-ink-soft);
  font-size: 0.92rem;
}
.goal-list li { margin-bottom: 0.4rem; }

.learning-value-card { grid-column: 1 / -1; }
.learning-value-card .egg-card-head { align-items: center; }
.learning-value-badge { padding: .22rem .55rem; border-radius: 999px; background: #eef2ff; color: #3730a3; font-size: .76rem; font-weight: 800; }
.learning-value-message { margin: .55rem 0 .75rem; color: #f1f5fb; }
.learning-value-progress { height: .7rem; overflow: hidden; border-radius: 999px; background: #e5e7eb; }
.learning-value-progress > span { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--color-indigo, #3949ab), var(--color-gold, #d99b2b)); }
.learning-value-count { margin: .45rem 0 .8rem; color: #93a2b8; }
.learning-value-count strong { color: #f1f5fb; font-size: 1.35rem; }
.learning-value-stats { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .65rem; margin: 0 0 .75rem; }
.learning-value-stats div { padding: .7rem; border: 1px solid #e2e8f0; border-radius: 10px; background: #f8fafc; }
.learning-value-stats dt { font-size: .76rem; color: var(--color-muted, #667085); }
.learning-value-stats dd { margin: .15rem 0 0; font-weight: 800; }
.learning-value-card .modal-note { color: #93a2b8; }
body[data-theme="light"] .learning-value-message,
body[data-theme="cute"] .learning-value-message,
body[data-theme="light"] .learning-value-count strong,
body[data-theme="cute"] .learning-value-count strong { color: #0f172a; }
body[data-theme="light"] .learning-value-count,
body[data-theme="cute"] .learning-value-count,
body[data-theme="light"] .learning-value-card .modal-note,
body[data-theme="cute"] .learning-value-card .modal-note { color: #64748b; }

.activity-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}
.activity-card {
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  cursor: default;
}
.activity-card h4 { font-size: 0.96rem; font-weight: 800; }
.activity-card p { font-size: 0.85rem; color: var(--color-ink-soft); }
.activity-tags { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-top: 0.2rem; }
.activity-foot {
  margin-top: auto;
  display: flex;
  justify-content: flex-end;
}

/* ---------- Chapters (compare layout) ---------- */
.chapter-block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.4rem 1.5rem;
  margin-bottom: 1.1rem;
  box-shadow: var(--shadow-sm);
}
.chapter-block h4 { font-size: 1rem; font-weight: 800; margin-bottom: 0.8rem; }
.chapter-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 720px) {
  .chapter-compare { grid-template-columns: 1fr; }
}
.chapter-col { border-radius: var(--radius-sm); padding: 0.9rem 1rem; }
.chapter-col.original { background: var(--color-surface-alt); }
.chapter-col.updated { background: #ECFDF5; }
.chapter-col .col-label {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
  display: block;
}
.chapter-col.original .col-label { color: var(--color-ink-soft); }
.chapter-col.updated .col-label { color: var(--color-success); }
.chapter-col p { font-size: 0.88rem; color: var(--color-ink-soft); }

/* ---------- News ---------- */
.news-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}
.news-list { display: flex; flex-direction: column; gap: 1.1rem; }
.news-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.3rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  box-shadow: var(--shadow-sm);
}
.news-item .news-date {
  font-size: 0.78rem;
  color: var(--color-muted);
  font-weight: 700;
}
.news-item h3 { font-size: 1.08rem; font-weight: 800; }
.news-item p { font-size: 0.9rem; color: var(--color-ink-soft); }
.news-item .news-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.3rem;
}

/* ---------- Subjects ---------- */
.subject-method-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.05rem 1.25rem;
  margin-bottom: 0.85rem;
  cursor: default;
}
.subject-method-item p { font-size: 0.92rem; }
.subject-method-item .method-source {
  font-size: 0.76rem;
  color: var(--color-muted);
  margin-top: 0.4rem;
}

/* ---------- Pricing ---------- */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.6rem;
}
@media (max-width: 860px) {
  .pricing-grid { grid-template-columns: 1fr; }
}
.pricing-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 2.1rem 1.7rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  box-shadow: var(--shadow-sm);
}
.pricing-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.pricing-card.featured {
  border: 2px solid var(--color-gold);
  box-shadow: var(--shadow-gold);
  position: relative;
}
.pricing-card.featured::before {
  content: "추천";
  position: absolute;
  top: -13px;
  right: 22px;
  background: var(--color-gold);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 800;
  padding: 0.28rem 0.75rem;
  border-radius: 999px;
}
.pricing-card h3 { font-size: 1.18rem; font-weight: 800; }
.pricing-price { font-family: var(--font-display); font-size: 1.85rem; font-weight: 700; color: var(--color-indigo); }
.pricing-price span { font-family: var(--font-sans); font-size: 0.9rem; color: var(--color-muted); font-weight: 600; }
.pricing-features { display: flex; flex-direction: column; gap: 0.6rem; }
.pricing-features li { font-size: 0.88rem; color: var(--color-ink-soft); padding-left: 1.4rem; position: relative; }
.pricing-features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: 800;
}
.pricing-features li.unavailable { color: var(--color-muted); text-decoration: line-through; }
.pricing-features li.unavailable::before { content: "-"; color: var(--color-muted); }

/* ---------- Detail page ---------- */
.detail-hero {
  display: flex;
  gap: 2rem;
  margin-bottom: 2.2rem;
  flex-wrap: wrap;
}
.detail-hero .detail-cover {
  width: 190px;
  flex-shrink: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  aspect-ratio: 3/4;
  background: var(--color-indigo-light);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
}
.detail-hero .detail-info { flex: 1; min-width: 260px; }
.detail-hero h1 { font-size: 1.7rem; font-weight: 700; margin-bottom: 0.65rem; }
.detail-hero .detail-audience { color: var(--color-muted); font-size: 0.9rem; margin-bottom: 0.8rem; }
.detail-hero .detail-summary { color: var(--color-ink-soft); font-size: 0.95rem; margin-bottom: 1rem; }
.detail-actions { display: flex; gap: 0.6rem; flex-wrap: wrap; align-items: center; }

.upgrade-badge-note {
  display: inline-block;
  background: var(--color-gold-light);
  color: var(--color-gold-dark);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 0.32rem 0.75rem;
  border-radius: var(--radius-xs);
  margin-bottom: 0.8rem;
}

.sources-box {
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.3rem 1.5rem;
  margin-top: 2rem;
}
.sources-box h3 { font-size: 0.95rem; font-weight: 800; margin-bottom: 0.7rem; }
.sources-box ol { padding-left: 1.2rem; }
.sources-box li { font-size: 0.8rem; color: var(--color-ink-soft); margin-bottom: 0.4rem; word-break: break-all; }

/* ---------- Lock / gate ---------- */
.gate-box {
  background: var(--color-surface);
  border: 2px dashed var(--color-border-strong);
  border-radius: var(--radius-xl);
  padding: 3.2rem 2rem;
  text-align: center;
  margin: 2rem 0;
}
.gate-box .gate-icon { font-size: 2.6rem; margin-bottom: 1rem; }
.gate-box h3 { font-size: 1.25rem; font-weight: 800; margin-bottom: 0.6rem; }
.gate-box p { color: var(--color-ink-soft); margin-bottom: 1.5rem; }

/* ---------- Share ---------- */
.share-wrap { position: relative; display: inline-block; }
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  padding: 0.42rem 0.8rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--color-ink-soft);
}
.share-btn:hover { border-color: var(--color-indigo); color: var(--color-indigo); transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.share-menu {
  position: absolute;
  bottom: calc(100% + 8px);
  right: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: 0.5rem;
  min-width: 170px;
  z-index: 60;
}
.share-menu button {
  display: block;
  width: 100%;
  text-align: left;
  background: transparent;
  border: none;
  padding: 0.6rem 0.75rem;
  border-radius: var(--radius-xs);
  font-size: 0.82rem;
  cursor: pointer;
}
.share-menu button:hover { background: var(--color-bg); }
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-navy);
  color: #fff;
  padding: 0.75rem 1.25rem;
  border-radius: 999px;
  font-size: 0.85rem;
  z-index: 500;
  box-shadow: var(--shadow-lg);
  animation: fadein 0.2s ease;
}
@keyframes fadein { from { opacity: 0; transform: translate(-50%, 8px); } to { opacity: 1; transform: translate(-50%, 0); } }

/* ---------- Audience/Grade quick links ---------- */
.quicklink-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1.1rem;
}
.quicklink-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.3rem 1rem;
  text-align: center;
  font-weight: 700;
  font-size: 0.92rem;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}
.quicklink-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); border-color: var(--color-indigo); }

/* --- Unified audience thumbnails ("coin" frame) ---------------------------
   8개 대상 썸네일(초등/중등/고등/학부모/시니어/교사/관리자/대학생·청년)은
   원본 비율·해상도·배경 톤이 제각각(깔끔한 원형 AI 일러스트 vs 저해상 북커버 크롭).
   이미지를 재생성할 수 없으므로 CSS로만 동일한 원형 프레임에 담아 한 세트로 정규화한다.
   테마별 색은 전부 CSS 변수를 사용하고, 오버레이는 반투명이라 다크/라이트/큐트 공통 동작. */
.quicklink-card .qc-thumb-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 92px;
  height: 92px;
  margin: 0 auto 0.7rem;
  position: relative;
  border-radius: 50%;
  overflow: hidden;
  /* 투명/여백 있는 크롭 뒤를 채워 빈틈이 배경으로 뚫려 보이지 않게 */
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  box-shadow: inset 0 1px 3px rgba(11, 18, 32, 0.10), 0 2px 6px rgba(11, 18, 32, 0.06);
  transition: box-shadow var(--dur-base) var(--ease-premium),
              border-color var(--dur-base) var(--ease-premium);
}
.quicklink-card .qc-thumb {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  /* 비율이 달라도 프레임을 꽉 채우되(레터박스 없이) 의도된 크롭처럼 보이도록 */
  object-fit: cover;
  object-position: center 42%;
  /* 톤 편차를 살짝 눌러 통일감만 주고, 좋은 일러스트는 훼손하지 않는 미세 보정 */
  filter: saturate(1.04) contrast(1.02);
  transition: transform var(--dur-base) var(--ease-premium);
}
/* 상단 하이라이트 + 하단 그림자 + 이너 링: 북커버 크롭과 AI 일러스트를 같은 "코인"으로 */
.quicklink-card .qc-thumb-wrap::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  pointer-events: none;
  background: linear-gradient(180deg,
              rgba(255, 255, 255, 0.22) 0%,
              rgba(255, 255, 255, 0) 44%,
              rgba(11, 18, 32, 0.12) 100%);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.30),
              inset 0 0 0 3px rgba(11, 18, 32, 0.04);
}
/* 폴백 이모지도 동일 프레임 안에서 가운데 정렬(썸네일 로드 실패 시 노출) */
.quicklink-card .qc-icon {
  position: relative;
  z-index: 1;
  font-size: 2rem;
  line-height: 1;
  margin: 0;
}
/* 사이트 카드 상호작용과 맞춘 호버: 썸네일 살짝 확대 + 인디고 글로우 */
.quicklink-card:hover .qc-thumb { transform: scale(1.06); }
.quicklink-card:hover .qc-thumb-wrap {
  border-color: var(--color-indigo);
  box-shadow: inset 0 1px 3px rgba(11, 18, 32, 0.10), 0 4px 14px rgba(79, 70, 229, 0.22);
}

/* ---------- Gallery strip (콘텐츠 미리보기) ---------- */
.gallery-strip {
  position: relative;
  margin: 0 -0.25rem;
}
.gallery-track {
  display: flex;
  gap: 1.1rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 0.35rem 0.25rem 1.1rem;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
}
.gallery-track::-webkit-scrollbar { height: 8px; }
.gallery-track::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 999px; }
.gallery-item {
  flex: 0 0 auto;
  width: 220px;
  scroll-snap-align: start;
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
  padding: 0;
}
.gallery-item img {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
  display: block;
}
.gallery-item:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--color-indigo); }
.gallery-item-caption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 0.7rem 0.8rem;
  background: linear-gradient(to top, rgba(11,18,32,0.85), transparent);
  color: #fff;
  font-size: 0.78rem;
  line-height: 1.4;
  text-align: left;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity var(--dur-base) var(--ease-premium), transform var(--dur-base) var(--ease-premium);
}
.gallery-item:hover .gallery-item-caption { opacity: 1; transform: translateY(0); }
.gallery-item-tag {
  display: block;
  font-size: 0.68rem;
  font-weight: 800;
  color: var(--color-gold);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.15rem;
}

/* ---------- Lightbox (갤러리 확대보기, .modal-overlay/.modal 재사용) ---------- */
.lightbox-modal {
  max-width: 720px;
  background: var(--color-navy);
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2.2rem 1.6rem 1.6rem;
}
.lightbox-stage {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  max-height: 66vh;
}
.lightbox-img {
  max-width: 100%;
  max-height: 66vh;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  object-fit: contain;
}
.lightbox-caption {
  margin-top: 1rem;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.82);
  text-align: center;
}
.lightbox-nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(255,255,255,0.08);
  color: #fff;
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.lightbox-nav:hover { background: rgba(255,255,255,0.18); transform: translateY(-50%) scale(1.08); }
.lightbox-prev { left: 0.75rem; }
.lightbox-next { right: 0.75rem; }
.lightbox-overlay .modal-close { background: rgba(255,255,255,0.1); color: #fff; }
.lightbox-overlay .modal-close:hover { background: rgba(255,255,255,0.2); }

/* ---------- 404 ---------- */
.notfound {
  text-align: center;
  padding: 5rem 1rem;
}
.notfound h1 { font-family: var(--font-display); font-size: 3.2rem; margin-bottom: 1rem; }
.notfound p { color: var(--color-muted); margin-bottom: 1.5rem; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-navy);
  color: #CBD1E0;
  padding: 3.5rem 0 1.5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2rem;
}
@media (max-width: 780px) {
  .footer-grid { grid-template-columns: 1fr; }
}
.footer-logo { font-family: var(--font-display); color: #fff; font-weight: 700; font-size: 1.1rem; margin-bottom: 0.65rem; }
.footer-desc { font-size: 0.85rem; line-height: 1.7; }
.footer-sns { display: flex; gap: 0.6rem; margin-top: 1rem; flex-wrap: wrap; }
.footer-sns a {
  border: 1px solid rgba(255,255,255,0.16);
  border-radius: 999px;
  padding: 0.32rem 0.9rem;
  font-size: 0.78rem;
}
.footer-sns a:hover { border-color: var(--color-gold); color: var(--color-gold); transform: translateY(-2px); }
.footer-heading { color: #fff; font-weight: 800; font-size: 0.9rem; margin-bottom: 0.9rem; }
.footer-copyright-note { font-size: 0.8rem; line-height: 1.7; margin-bottom: 0.8rem; }
.footer-booklist li { font-size: 0.78rem; padding: 0.22rem 0; border-bottom: 1px dotted rgba(255,255,255,0.14); }
.footer-links ul li { margin-bottom: 0.5rem; }
.footer-links a { font-size: 0.85rem; }
.footer-links a:hover { color: var(--color-gold); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.12);
  padding-top: 1.2rem;
  font-size: 0.78rem;
  color: #6B7385;
  text-align: center;
}

/* ---------- Print ---------- */
@media print {
  .site-header, .site-footer, .share-wrap, .role-switcher, .tabs, .nav-toggle { display: none !important; }
  body { background: #fff; }
  .book-card, .activity-card, .chapter-block { box-shadow: none; border: 1px solid #ccc; }
}

/* ---------- Responsive nav ---------- */
@media (max-width: 960px) {
  .header-inner { min-height: var(--header-h-mobile, 56px); }     /* onae 공통헤더 표준: 모바일 56px */
  .nav-toggle { display: flex; }
  .main-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    order: 4;
    margin-left: 0;
    padding-top: 0.5rem;
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 0.75rem 0.5rem; border-bottom: 1px solid var(--color-border); border-radius: 0; font-size: 1rem; }
  .header-actions { margin-left: auto; gap: 0.4rem; }
  .pricing-grid { grid-template-columns: 1fr; }
  .hero-inner { flex-direction: column; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); max-width: 100%; }
}

@media (max-width: 640px) {
  /* 좁은 화면에서 액션 클러스터를 압축: 부제/상태 칩을 숨기고 아이콘 버튼만 유지 */
  .role-switcher-sub { display: none; }
  .role-switcher-btn--primary { padding: 0.45rem 0.7rem; }
  .role-badge { display: none; }
}

@media (max-width: 520px) {
  .hero { padding: 2.4rem 1.4rem; }
  .detail-hero { flex-direction: column; }
  .detail-hero .detail-cover { width: 150px; }
  .hero-stack { width: 180px; height: 220px; }
  .hero-stack-item .book3d { width: 120px; }
}

/* ==========================================================================
   Learn (챕터 목록 · 리더) + 게이팅 + 모달 — learn.js / auth.js 컴포넌트
   ========================================================================== */

/* ---------- Chapter cards ---------- */
.chapter-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.2rem;
}
.chapter-card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.15rem 1.25rem;
  box-shadow: var(--shadow-sm);
  position: relative;
}
.chapter-card::after {
  content: "→";
  position: absolute;
  right: 1.1rem;
  bottom: 1.1rem;
  opacity: 0;
  transform: translateX(-6px);
  color: var(--color-indigo);
  font-weight: 800;
  transition: opacity var(--dur-base) var(--ease-premium), transform var(--dur-base) var(--ease-premium);
}
.chapter-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); border-color: var(--color-indigo); }
.chapter-card:hover::after { opacity: 1; transform: translateX(0); }
.chapter-card.locked { opacity: 0.8; background: var(--color-surface-alt); }
.chapter-card h3 { font-size: 0.98rem; font-weight: 800; padding-right: 1.4rem; }
.chapter-card p { font-size: 0.83rem; color: var(--color-ink-soft); flex: 1; }
.chapter-card-head { display: flex; align-items: center; gap: 0.5rem; }
.chapter-no {
  display: inline-block;
  background: var(--color-indigo-light);
  color: var(--color-indigo-dark);
  font-size: 0.72rem;
  font-weight: 800;
  padding: 0.22rem 0.6rem;
  border-radius: 999px;
}
.lock-icon-sm { margin-left: auto; font-size: 0.85rem; }
.chapter-card-foot { min-height: 1.1rem; }
.chapter-card-art {
  margin: -1.15rem -1.25rem 0.3rem;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--color-surface-alt);
}
.chapter-card-art img { width: 100%; height: 100%; object-fit: cover; display: block; }
.chapter-reader-art { background: var(--color-surface-alt); }
.chapter-progress { font-size: 0.72rem; font-weight: 800; padding: 0.16rem 0.6rem; border-radius: 999px; }
.chapter-progress.read { background: #DCFCE7; color: #166534; }
.chapter-progress.current { background: var(--color-gold-light); color: var(--color-gold-dark); }

/* ---------- Reader ---------- */
.reader-head {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.7rem;
  flex-wrap: wrap;
}
.reader-progress {
  flex: 1;
  min-width: 120px;
  height: 6px;
  background: var(--color-border);
  border-radius: 999px;
  overflow: hidden;
}
.reader-progress-bar { height: 100%; background: linear-gradient(90deg, var(--color-indigo), var(--color-gold)); border-radius: 999px; transition: width 0.3s var(--ease-premium); }
.reader-progress-label { font-size: 0.78rem; font-weight: 700; color: var(--color-muted); }

.chapter-reader { max-width: 820px; margin: 0 auto; }
.chapter-reader-head { margin-bottom: 2.1rem; }
.chapter-reader-head h1 { font-family: var(--font-display); font-size: 1.8rem; font-weight: 700; margin: 0.75rem 0 0.6rem; }
.chapter-intro { color: var(--color-ink-soft); font-size: 1rem; line-height: 1.8; margin-bottom: 1rem; }
.chapter-objectives { margin-bottom: 1rem; }
.chapter-reader-actions { display: flex; gap: 0.6rem; }

.section-list { display: flex; flex-direction: column; gap: 1.5rem; margin-bottom: 2rem; }
.section-block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.6rem 1.7rem;
  box-shadow: var(--shadow-sm);
}
.section-block-head {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.95rem;
}
.section-block-head h3 { font-size: 1.1rem; font-weight: 800; flex: 1; }
.section-block-body p { font-size: 0.93rem; line-height: 1.85; color: var(--color-ink-soft); margin-bottom: 0.7rem; }
.section-sources { margin-top: 1rem; padding: .75rem .9rem; border: 1px solid var(--color-border); border-radius: .7rem; background: var(--color-surface-alt); font-size: .84rem; }
.section-sources summary { cursor: pointer; font-weight: 750; color: var(--color-primary); }
.section-sources ol { margin: .7rem 0 .35rem; padding-left: 1.35rem; }
.section-sources li { margin: .35rem 0; overflow-wrap: anywhere; }
.section-sources a { color: var(--color-primary); text-decoration: underline; text-underline-offset: 2px; }
.section-sources p { margin: .45rem 0 0; font-size: .78rem; }
.section-source-date { white-space: nowrap; color: var(--color-ink-muted); }
.section-block.is-locked { background: var(--color-surface-alt); }

/* ---------- 게이팅: 블러 미리보기 + 잠금 오버레이 ---------- */
.section-locked { position: relative; }
.section-locked .lock-preview {
  filter: blur(5px);
  user-select: none;
  pointer-events: none;
  margin-bottom: 0;
  min-height: 3.2rem;
}
.section-locked .lock-overlay {
  position: relative;
  margin-top: -2.6rem;
  background: linear-gradient(to bottom, rgba(255,255,255,0) 0%, var(--color-surface) 34%);
  text-align: center;
  padding: 2.4rem 1rem 0.6rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
}
.section-block.is-locked .lock-overlay {
  background: linear-gradient(to bottom, rgba(255,255,255,0) 0%, var(--color-surface-alt) 34%);
}
.lock-overlay .lock-icon { font-size: 1.7rem; }
.lock-overlay p { font-size: 0.88rem; font-weight: 700; color: var(--color-ink); margin: 0; }
.section-locked-compact .lock-preview { min-height: 2.2rem; }
.section-locked .lock-overlay-compact {
  min-height: 4.5rem;
  padding: 2rem 1rem 0.8rem;
  gap: 0.35rem;
}
.lock-overlay-compact .lock-icon { font-size: 1.2rem; }
.lock-overlay-compact p { max-width: 42rem; font-weight: 600; color: var(--color-ink-soft); }

/* ---------- howto ---------- */
.tool-badge {
  display: inline-block;
  background: #EDE9FE;
  color: #5B21B6;
  font-size: 0.76rem;
  font-weight: 800;
  padding: 0.28rem 0.75rem;
  border-radius: 999px;
  margin-bottom: 0.8rem;
}
.howto-steps { list-style: none; display: flex; flex-direction: column; gap: 0.75rem; margin-bottom: 0.9rem; }
.howto-steps li { display: flex; gap: 0.75rem; align-items: flex-start; }
.howto-steps .step-no {
  flex-shrink: 0;
  width: 1.55rem;
  height: 1.55rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-indigo), var(--color-indigo-dark));
  color: #fff;
  font-size: 0.76rem;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.howto-steps .step-text { font-size: 0.9rem; line-height: 1.7; color: var(--color-ink-soft); }
.tip-box {
  background: var(--color-gold-light);
  border-radius: var(--radius-md);
  padding: 0.9rem 1.05rem;
  font-size: 0.86rem;
  color: var(--color-gold-dark);
  line-height: 1.7;
}

/* ---------- prompt ---------- */
.prompt-box {
  background: var(--color-navy);
  border-radius: var(--radius-md);
  padding: 1.05rem 1.15rem;
  margin-bottom: 0.9rem;
}
.prompt-code {
  color: #E7E9F3;
  font-family: "SF Mono", "Consolas", "D2Coding", monospace;
  font-size: 0.84rem;
  line-height: 1.75;
  white-space: pre-wrap;
  word-break: break-word;
  margin-bottom: 0.8rem;
}
.prompt-box .copy-prompt-btn { border-color: rgba(255,255,255,0.3); color: #E7E9F3; background: transparent; }
.prompt-box .copy-prompt-btn:hover { border-color: var(--color-gold); color: var(--color-gold); background: transparent; transform: translateY(-2px); }
.prompt-box .copy-prompt-btn.copied { border-color: var(--color-success); color: var(--color-success); }
.prompt-example {
  background: var(--color-surface-alt);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.9rem 1rem;
}
.prompt-example strong { display: block; font-size: 0.78rem; margin-bottom: 0.35rem; color: var(--color-muted); }
.prompt-example p { font-size: 0.88rem; margin: 0; }

/* ---------- activity meta ---------- */
.activity-meta { display: flex; gap: 0.45rem; flex-wrap: wrap; margin-top: 0.6rem; }
.chip.duration-chip { background: #E0F2FE; color: #075985; }

/* ---------- video ---------- */
.video-embed-wrap {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-bottom: 0.7rem;
}
.video-loading, .video-empty { font-size: 0.86rem; color: var(--color-muted); padding: 0.8rem 0; }
.video-embed {
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-navy);
  aspect-ratio: 16/9;
  position: relative;
  box-shadow: var(--shadow-sm);
}
.video-embed:hover { box-shadow: var(--shadow-md); }
.video-thumb-btn { position: absolute; inset: 0; width: 100%; padding: 0; background: transparent; border: none; cursor: pointer; }
.video-thumb-btn img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform var(--dur-slow) var(--ease-premium); }
.video-thumb-btn:hover img { transform: scale(1.05); }
.video-play-icon {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 3.2rem;
  height: 3.2rem;
  border-radius: 50%;
  background: rgba(11,18,32,0.68);
  border: 1.5px solid rgba(255,255,255,0.35);
  color: #fff;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--dur-base) var(--ease-premium), transform var(--dur-base) var(--ease-premium), box-shadow var(--dur-base) var(--ease-premium);
}
.video-thumb-btn:hover .video-play-icon { background: var(--color-indigo); transform: translate(-50%, -50%) scale(1.14); box-shadow: 0 0 0 8px rgba(79,70,229,0.18); }
.video-meta {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 0.65rem 0.85rem;
  background: linear-gradient(to top, rgba(11,18,32,0.88), transparent);
  display: flex;
  flex-direction: column;
  gap: 0.18rem;
}
.video-title { color: #fff; font-size: 0.8rem; font-weight: 700; line-height: 1.4; }
.video-channel {
  color: var(--color-gold);
  font-size: 0.72rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}
.video-channel::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--color-gold);
  display: inline-block;
}
.video-iframe { width: 100%; height: 100%; display: block; border: 0; }
.video-more-link { margin-top: 0.2rem; }

/* ---------- mission / checklist / chapter nav ---------- */
.mission-box {
  background: linear-gradient(135deg, var(--color-indigo-light), #F5F4FF);
  border: 1px solid rgba(79,70,229,0.25);
  border-radius: var(--radius-xl);
  padding: 1.5rem 1.7rem;
  margin-bottom: 1.7rem;
}
.mission-box h3 { font-size: 1.04rem; font-weight: 800; margin-bottom: 0.6rem; }
.mission-box p { font-size: 0.9rem; line-height: 1.75; color: var(--color-ink-soft); }
.mission-deliverable {
  margin-top: 0.8rem;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 0.75rem 0.95rem;
  font-size: 0.86rem;
}
.checklist-box {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 1.5rem 1.7rem;
  margin-bottom: 1.7rem;
}
.checklist-box h3 { font-size: 1.04rem; font-weight: 800; margin-bottom: 0.9rem; }
.checklist-list { list-style: none; display: flex; flex-direction: column; gap: 0.65rem; }
.checklist-item label { display: flex; gap: 0.6rem; align-items: flex-start; cursor: pointer; font-size: 0.9rem; }
.checklist-item input[type="checkbox"] { margin-top: 0.2rem; accent-color: var(--color-indigo); cursor: pointer; }
.checklist-item input[type="checkbox"]:checked + span { text-decoration: line-through; color: var(--color-muted); }
.chapter-nav {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  flex-wrap: wrap;
  border-top: 1px solid var(--color-border);
  padding-top: 1.5rem;
}

/* ---------- Modal (회원가입 / 구매·구독) ---------- */
.network-status-banner{position:fixed;left:50%;bottom:1rem;transform:translateX(-50%);z-index:10020;width:min(92vw,720px);box-sizing:border-box;padding:.8rem 1rem;border-radius:.75rem;background:#172033;color:#fff;box-shadow:0 8px 24px rgba(0,0,0,.24);font-weight:700;text-align:center}.network-status-banner[data-network-state="offline"]{background:#7a2e0e}.network-status-banner[hidden]{display:none}
.pricing-institutional{margin:1.2rem 0;padding:1.2rem;border:1px solid var(--color-border);border-radius:1rem;background:var(--color-surface-alt);display:grid;grid-template-columns:minmax(0,.8fr) minmax(280px,1.2fr);gap:1.25rem}.pricing-institutional h3{margin-top:0}.pricing-institutional form{display:grid;grid-template-columns:1fr 1fr;gap:.75rem}.pricing-institutional label{display:grid;gap:.35rem;font-weight:700}.pricing-institutional input,.pricing-institutional select,.pricing-institutional textarea{width:100%;box-sizing:border-box;padding:.7rem;border:1px solid var(--color-border);border-radius:.6rem;background:var(--color-surface);color:var(--color-ink)}.pricing-institutional textarea,.pricing-institutional .institutional-consent,.pricing-institutional button,.pricing-institutional [data-institutional-status]{grid-column:1/-1}.pricing-institutional .institutional-consent{display:flex;align-items:flex-start;font-weight:500}.pricing-institutional .institutional-consent input{width:auto;margin-top:.25rem}@media(max-width:720px){.pricing-institutional{grid-template-columns:1fr}.pricing-institutional form{grid-template-columns:1fr}.pricing-institutional label{grid-column:1}}
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(11, 18, 32, 0.6);
  backdrop-filter: blur(2px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  z-index: 400;
  animation: fadeinOverlay 0.15s ease;
}
@keyframes fadeinOverlay { from { opacity: 0; } to { opacity: 1; } }
.modal {
  position: relative;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 460px;
  max-height: 88vh;
  overflow-y: auto;
  padding: 1.9rem 1.8rem;
  animation: modalIn 0.22s var(--ease-premium);
}
@keyframes modalIn { from { opacity: 0; transform: translateY(14px) scale(0.98); } to { opacity: 1; transform: translateY(0) scale(1); } }
.modal h2 { font-family: var(--font-display); font-size: 1.3rem; font-weight: 700; margin-bottom: 0.5rem; }
.modal-close {
  position: absolute;
  top: 0.9rem;
  right: 0.9rem;
  width: 2.1rem;
  height: 2.1rem;
  border: none;
  background: var(--color-surface-alt);
  border-radius: 50%;
  font-size: 1.1rem;
  line-height: 1;
  color: var(--color-muted);
  cursor: pointer;
}
.modal-close:hover { background: var(--color-border); color: var(--color-ink); transform: rotate(90deg); }
.modal-note { font-size: 0.82rem; color: var(--color-muted); margin-bottom: 1rem; line-height: 1.6; }
.modal-form { display: flex; flex-direction: column; gap: 0.4rem; }
.modal label, .modal-form label { font-size: 0.82rem; font-weight: 700; margin-top: 0.5rem; }
.modal input[type="text"], .modal input[type="email"], .modal select {
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  padding: 0.68rem 0.85rem;
  font-size: 0.9rem;
  background: var(--color-surface-alt);
}
.modal input:focus, .modal select:focus { outline: 2px solid var(--color-indigo); border-color: var(--color-indigo); }
.form-error { color: #DC2626; font-size: 0.78rem; }
.modal-tabs { display: flex; gap: 0.4rem; margin-bottom: 1.1rem; }
.modal-tab {
  flex: 1;
  border: 1px solid var(--color-border);
  background: var(--color-surface-alt);
  border-radius: var(--radius-xs);
  padding: 0.58rem 0.4rem;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-ink-soft);
}
.modal-tab.active { background: var(--color-indigo); border-color: var(--color-indigo); color: #fff; }
.modal-divider { border-top: 1px dashed var(--color-border); margin: 1.2rem 0 1rem; }
.paper-links { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.modal .pricing-features { margin-bottom: 1rem; }

/* ---------- Trust / social-proof section (홈: 신뢰 배지 + 대상별 표지 + 베타 후기) ---------- */
.trust-social-proof-section .trust-badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 1.5rem;
}
.trust-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--color-gold-light);
  color: var(--color-gold-dark);
  font-weight: 800;
  font-size: 0.88rem;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  border: 1px solid #EAD9AE;
}
.trust-audience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(96px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}
.trust-audience-cover {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.45rem;
  text-align: center;
}
.trust-audience-cover-img.book-cover {
  width: 100%;
  aspect-ratio: 3 / 4;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}
.trust-audience-label {
  font-size: 0.72rem;
  color: var(--color-ink-soft);
  font-weight: 600;
  line-height: 1.35;
}
.trust-reviews-block {
  background: var(--color-surface-alt);
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-md);
  padding: 1.6rem 1.5rem;
}
.trust-reviews-heading {
  font-size: 1rem;
  font-weight: 800;
  margin-bottom: 0.9rem;
  color: var(--color-ink);
}
.trust-reviews-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  text-align: center;
  padding: 1.2rem 0.5rem;
  color: var(--color-ink-soft);
}
.trust-reviews-empty-icon {
  font-size: 1.8rem;
}
.trust-reviews-empty p {
  font-size: 0.88rem;
  max-width: 480px;
  line-height: 1.6;
  color: var(--color-ink-soft);
}

/* ==========================================================================
   .lock-price-anchor — 잠금 카드 내 가격 안내 (종이책/온라인/구독)
   테마(다크/라이트/큐트)에서 공통으로 쓰이는 --color-* 변수를 사용해
   3개 span이 붙어 보이지 않도록 카드형 pill로 구분한다.
   ========================================================================== */
.lock-price-anchor {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin: 0.7rem 0;
  padding: 0;
  list-style: none;
}
.lock-price-anchor span {
  display: inline-flex;
  align-items: center;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  color: var(--color-ink-soft);
  border-radius: var(--radius-xl);
  padding: 0.32rem 0.85rem;
  font-size: 0.82rem;
  font-weight: 600;
  line-height: 1.4;
  white-space: normal;
}
.lock-price-anchor span:first-child {
  background: var(--color-surface);
  color: var(--color-ink);
  border-color: var(--color-border-strong);
  font-weight: 700;
}
.lock-price-anchor span:last-child {
  background: var(--color-accent-light);
  border-color: var(--color-accent);
  color: var(--color-ink);
}