/* ===========================
   比爸 BD — 黑河沉浸設計系統
   Dark River Immersive Design
   =========================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg:       #000000;
  --bg2:      #080808;
  --bg3:      #0f0f0f;
  --surface:  rgba(255,255,255,0.03);
  --surface2: rgba(255,255,255,0.06);
  --border:   rgba(255,255,255,0.07);
  --border2:  rgba(255,255,255,0.12);
  --white:    #f0f0f0;
  --text:     #e8e8e8;
  --text-dim: rgba(240,240,240,0.5);
  --text-xs:  rgba(240,240,240,0.28);
  --accent:   #f0f0f0;
  --accent-gold: #c9a84c;
  --glow:     rgba(255,255,255,0.06);
  --radius:   14px;
  --radius-sm:8px;
  --nav-h:    60px;
  --font:     -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "PingFang TC", "Microsoft JhengHei", sans-serif;
}
body.light {
  --bg:       #f8f8f6;
  --bg2:      #f0f0ee;
  --bg3:      #e8e8e6;
  --surface:  rgba(0,0,0,0.03);
  --surface2: rgba(0,0,0,0.06);
  --border:   rgba(0,0,0,0.07);
  --border2:  rgba(0,0,0,0.12);
  --white:    #1a1a1a;
  --text:     #1a1a1a;
  --text-dim: rgba(26,26,26,0.55);
  --text-xs:  rgba(26,26,26,0.32);
  --accent:   #1a1a1a;
  --glow:     rgba(0,0,0,0.06);
}
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
h1,h2,h3,h4,h5 { font-weight: 700; letter-spacing: -0.02em; line-height: 1.1; }
p { line-height: 1.8; }
a { color: var(--accent); text-decoration: none; transition: opacity .2s; }
a:hover { opacity: .65; }

/* ── 水波紋背景 Canvas ── */
.river-canvas {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.55;
}

/* ── Navigation ── */
#nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 999;
  height: var(--nav-h);
  background: rgba(0,0,0,0.72);
  backdrop-filter: saturate(120%) blur(28px);
  -webkit-backdrop-filter: saturate(120%) blur(28px);
  border-bottom: 1px solid var(--border);
  transition: background .3s;
}
body.light #nav {
  background: rgba(248,248,246,0.82);
  border-bottom-color: var(--border);
}
.nav-wrap {
  max-width: 1100px; margin: 0 auto; height: 100%;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px;
}
.nav-logo {
  display: flex; align-items: center;
  text-decoration: none;
  opacity: 0.9;
  transition: opacity .2s;
  flex-shrink: 0;
}
.nav-logo:hover { opacity: 1; }
.nav-logo-img { height: 30px; width: 30px; border-radius: 50%; display: block; }

/* 桌面版選單 — 置中 */
.nav-menu {
  display: flex; align-items: center;
  gap: 0; list-style: none;
  position: absolute; left: 50%; transform: translateX(-50%);
}
.nav-menu li a {
  display: flex; align-items: center;
  font-size: 13px; font-weight: 400;
  color: var(--text-dim);
  text-decoration: none;
  padding: 0 14px;
  height: var(--nav-h);
  letter-spacing: 0.01em;
  transition: color .2s;
  white-space: nowrap;
}
.nav-menu li a:hover,
.nav-menu li a.active { color: var(--white); opacity: 1; }

/* 漢堡選單 */
.nav-hamburger {
  display: none; flex-direction: column; justify-content: center; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 8px;
  width: 36px; height: 36px;
}
.nav-hamburger span {
  display: block; width: 18px; height: 1px;
  background: rgba(240,240,240,0.8); border-radius: 2px;
  transition: transform .35s cubic-bezier(0.4,0,0.2,1), opacity .25s ease;
  transform-origin: center;
}
.nav-hamburger.active span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-hamburger.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.active span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 手機全螢幕展開選單 */
.nav-menu.open {
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.97);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  padding: calc(var(--nav-h) + 40px) 32px 48px;
  gap: 0;
  overflow-y: auto;
  z-index: 998;
  transform: none;
  left: 0;
  animation: menuSlideIn .3s cubic-bezier(0.4,0,0.2,1) forwards;
}
@keyframes menuSlideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to   { opacity: 1; transform: none; }
}
.nav-menu.open li {
  border-bottom: 1px solid rgba(255,255,255,0.06);
  animation: menuItemIn .35s cubic-bezier(0.4,0,0.2,1) both;
}
.nav-menu.open li:nth-child(1) { animation-delay: .05s; }
.nav-menu.open li:nth-child(2) { animation-delay: .10s; }
.nav-menu.open li:nth-child(3) { animation-delay: .15s; }
.nav-menu.open li:nth-child(4) { animation-delay: .20s; }
.nav-menu.open li:last-child { border-bottom: none; }
@keyframes menuItemIn {
  from { opacity: 0; transform: translateX(-12px); }
  to   { opacity: 1; transform: none; }
}
.nav-menu.open li a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 32px;
  font-weight: 600;
  letter-spacing: -0.03em;
  color: rgba(240,240,240,0.9);
  height: auto;
  padding: 22px 0;
  width: 100%;
  text-decoration: none;
  transition: color .2s;
}
.nav-menu.open li a::after {
  content: "›";
  font-size: 28px;
  font-weight: 300;
  color: rgba(240,240,240,0.2);
  transition: transform .2s, color .2s;
}
.nav-menu.open li a:hover { color: #fff; opacity: 1; }
.nav-menu.open li a:hover::after { color: rgba(240,240,240,0.5); transform: translateX(4px); }
body.light .nav-menu.open { background: rgba(248,248,246,0.98); }
body.light .nav-menu.open li { border-bottom-color: rgba(0,0,0,0.06); }
body.light .nav-menu.open li a { color: rgba(26,26,26,0.85); }
body.light .nav-menu.open li a::after { color: rgba(26,26,26,0.2); }
body.light .nav-menu.open li a:hover { color: #000; }

/* 手機版全螢幕選單的獨立右上角關閉按鈕 */
.nav-menu-close { display: none; }
@media (max-width: 768px) {
  .nav-menu-close {
    position: fixed;
    top: calc((var(--nav-h) - 36px) / 2);
    right: 16px;
    z-index: 10001;
    width: 36px; height: 36px;
    display: none;
    align-items: center; justify-content: center;
    border: 1px solid rgba(255,255,255,0.16);
    border-radius: 50%;
    background: rgba(30,30,30,0.72);
    color: rgba(240,240,240,0.95);
    font-size: 20px;
    line-height: 1;
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
    transition: transform .2s ease, background .2s ease, color .2s ease;
  }
  .nav-menu-close { display: none !important; }
  .nav-menu-close.visible { display: flex !important; animation: navCloseIn .22s ease both; }
  .nav-menu.open ~ .nav-right-mobile .nav-hamburger { opacity: 0; pointer-events: none; }
  .nav-menu-close:hover, .nav-menu-close:active { background: rgba(70,70,70,0.9); color: #fff; transform: scale(0.94); }
  body.light .nav-menu-close { background: rgba(238,238,238,0.9); border-color: rgba(0,0,0,0.12); color: rgba(20,20,20,0.85); }
}
@keyframes navCloseIn {
  from { opacity: 0; transform: scale(.82) rotate(-45deg); }
  to { opacity: 1; transform: none; }
}

.nav-right-mobile { display: flex; align-items: center; gap: 4px; }
.nav-theme-wrap { display: flex; align-items: center; }
.nav-theme {
  background: none; border: none; cursor: pointer;
  font-size: 14px; padding: 4px 8px;
  color: var(--text-dim);
  transition: color .2s;
  line-height: 1;
}
.nav-theme:hover { color: var(--white); }

/* ── Layout ── */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.section { padding: 120px 0; }
.section-sm { padding: 64px 0; }
.divider { height: 1px; background: var(--border); }

/* ── Hero ── */
.hero {
  min-height: 100vh;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center;
  padding: 140px 24px 100px;
  position: relative; overflow: hidden;
  background: #000;
}
.hero-canvas { position: absolute; inset: 0; z-index: 0; }
.hero-content { position: relative; z-index: 1; max-width: 780px; }
.hero-eyebrow {
  font-size: 11px; font-weight: 500; letter-spacing: .18em;
  text-transform: uppercase; color: var(--text-xs);
  margin-bottom: 28px;
  opacity: 0; animation: fadeUp .9s .2s forwards;
}
.hero-title {
  font-size: clamp(52px, 9vw, 108px);
  font-weight: 700; color: var(--white);
  letter-spacing: -0.04em; line-height: 0.95;
  margin-bottom: 32px;
  opacity: 0; animation: fadeUp .9s .4s forwards;
}
.hero-title span { color: var(--white); opacity: 0.45; display: block; font-size: 0.52em; font-weight: 400; letter-spacing: -0.02em; margin-top: 16px; }
.hero-sub {
  font-size: clamp(15px, 2vw, 18px);
  color: var(--text-dim);
  max-width: 480px; margin: 0 auto 48px;
  font-weight: 400; line-height: 1.8;
  opacity: 0; animation: fadeUp .9s .6s forwards;
}
.hero-cta {
  display: flex; gap: 16px; justify-content: center; flex-wrap: wrap;
  opacity: 0; animation: fadeUp .9s .8s forwards;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 6px; padding: 13px 26px; border-radius: 980px;
  font-size: 14px; font-weight: 500; cursor: pointer;
  text-decoration: none; transition: all .25s; border: none;
  white-space: nowrap; letter-spacing: 0.01em;
}
.btn-primary {
  background: var(--white);
  color: #000;
}
.btn-primary:hover { background: rgba(240,240,240,0.85); transform: scale(1.02); opacity: 1; }
.btn-outline {
  background: transparent;
  color: var(--white);
  border: 1px solid var(--border2);
}
.btn-outline:hover { background: var(--surface2); transform: scale(1.02); opacity: 1; }
.btn-ghost {
  background: var(--surface);
  color: var(--text-dim);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--surface2); color: var(--white); opacity: 1; }
.btn-pink {
  background: transparent;
  color: var(--text-dim);
  border: 1px solid var(--border);
}
.btn-pink:hover { background: var(--surface); color: var(--white); opacity: 1; }
.btn-sm { padding: 8px 16px; font-size: 12px; }

/* ── Cards ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .35s, box-shadow .35s;
}
.card:hover { border-color: var(--border2); box-shadow: 0 16px 48px rgba(0,0,0,.6); }

/* ── Badge ── */
.badge {
  display: inline-block; padding: 3px 10px; border-radius: 980px;
  font-size: 11px; font-weight: 500; letter-spacing: .04em;
  background: var(--surface2);
  color: var(--text-dim);
  border: 1px solid var(--border);
}
.badge-purple { background: rgba(255,255,255,0.04); color: var(--text-dim); border-color: var(--border); }
.badge-green  { background: rgba(255,255,255,0.04); color: var(--text-dim); border-color: var(--border); }
.badge-hot    { background: rgba(255,255,255,0.04); color: var(--text-dim); border-color: var(--border); }

/* ── Section Header ── */
.section-header { text-align: center; margin-bottom: 72px; }
.section-eyebrow {
  font-size: 11px; font-weight: 500; letter-spacing: .16em;
  text-transform: uppercase; color: var(--text-xs);
  margin-bottom: 16px;
}
.section-title { font-size: clamp(28px, 4vw, 44px); color: var(--white); margin-bottom: 16px; }
.section-sub { font-size: 16px; color: var(--text-dim); max-width: 520px; margin: 0 auto; line-height: 1.8; }

/* ── Scroll Reveal ── */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s ease, transform .8s ease; }
.reveal.visible { opacity: 1; transform: none; }
.reveal-delay-1 { transition-delay: .1s; }
.reveal-delay-2 { transition-delay: .2s; }
.reveal-delay-3 { transition-delay: .3s; }
.reveal-delay-4 { transition-delay: .4s; }

/* ── Page Hero ── */
.page-hero {
  padding: calc(var(--nav-h) + 80px) 24px 80px;
  text-align: center;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.page-hero h1 { font-size: clamp(36px, 6vw, 64px); color: var(--white); margin-bottom: 14px; }
.page-hero p { font-size: 16px; color: var(--text-dim); }

/* ── Latest Bar ── */
.latest-bar {
  background: rgba(255,255,255,0.03);
  border-bottom: 1px solid var(--border);
  padding: 11px 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-dim);
  margin-top: var(--nav-h);
  letter-spacing: 0.01em;
}
.latest-bar strong { color: var(--white); font-weight: 500; }
.latest-bar a { color: var(--white); font-weight: 500; text-decoration: underline; text-decoration-color: var(--border2); text-underline-offset: 3px; }
.latest-bar a:hover { opacity: 0.7; }

/* ── Footer ── */
footer {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  padding: 56px 0 28px;
}
body.light footer { background: var(--bg2); border-top-color: var(--border); }
.footer-wrap { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-bottom: 1px solid var(--border);
  padding-bottom: 28px;
  margin-bottom: 20px;
}
.footer-col { padding: 0 16px; }
.footer-col:first-child { padding-left: 0; }
.footer-col:last-child { padding-right: 0; }
.footer-col-title {
  font-size: 11px; font-weight: 600;
  letter-spacing: .08em; text-transform: uppercase;
  color: var(--text-xs);
  margin-bottom: 14px; line-height: 1.4;
}
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a {
  font-size: 13px;
  color: var(--text-dim);
  text-decoration: none;
  transition: color .2s;
  line-height: 1.6;
}
.footer-col ul li a:hover { color: var(--white); opacity: 1; }
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 8px;
}
.footer-copy { font-size: 12px; color: var(--text-xs); line-height: 1.8; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 0; align-items: center; }
.footer-legal a {
  font-size: 12px;
  color: var(--text-xs);
  text-decoration: none;
  transition: color .2s;
  padding: 0 10px;
  border-right: 1px solid var(--border);
  line-height: 1;
}
.footer-legal a:last-child { border-right: none; }
.footer-legal a:hover { color: var(--white); opacity: 1; }
.footer-logo { display: none; }

/* ── Reading ── */
.progress-bar {
  position: fixed;
  top: var(--nav-h);
  left: 0; right: 0;
  height: 1px;
  background: transparent;
  z-index: 89;
}
.progress-fill {
  height: 100%;
  background: rgba(255,255,255,0.3);
  width: 0%;
  transition: width .1s;
}
.reading-body {
  max-width: 620px; margin: 0 auto;
  padding: calc(var(--nav-h) + 60px + 32px) 24px 120px;
}
.reading-chapter-title {
  font-size: clamp(28px, 5vw, 44px);
  color: var(--white);
  margin-bottom: 10px;
  letter-spacing: -0.03em;
  text-align: center;
  font-weight: 700;
}
.reading-meta {
  font-size: 12px;
  color: var(--text-xs);
  margin-bottom: 56px;
  text-align: center;
  letter-spacing: 0.04em;
}
.reading-content {
  font-size: 18px;
  line-height: 2.4;
  color: rgba(240,240,240,0.72);
  letter-spacing: 0.015em;
  text-align: center;
}
.reading-content p {
  margin-bottom: 1.8em;
  text-align: center;
}
.reading-nav {
  display: flex; gap: 10px;
  justify-content: center;
  padding: 48px 0;
  flex-wrap: wrap;
}

/* ── Chapter Transition ── */
body.page-transition {
  animation: pageOut .35s ease forwards;
}
@keyframes pageOut {
  from { opacity: 1; }
  to   { opacity: 0; }
}
.page-enter {
  animation: pageIn .5s ease forwards;
}
@keyframes pageIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ── Responsive ── */
@media (max-width: 768px) {
  :root { --nav-h: 52px; }
  .nav-menu { display: none; }
  .nav-menu.open {
    display: flex !important;
    position: fixed !important;
    top: 0 !important; left: 0 !important;
    right: 0 !important; bottom: 0 !important;
    width: 100vw !important; height: 100vh !important;
    z-index: 9999 !important;
    transform: none !important;
    background: rgba(0,0,0,0.97) !important;
    backdrop-filter: blur(40px) !important;
    -webkit-backdrop-filter: blur(40px) !important;
  }
  .nav-hamburger { display: flex; }
  .nav-wrap { justify-content: space-between; padding: 0 18px; }
  .nav-logo { position: static; }
  .nav-theme-wrap { position: static; }
  .nav-right-mobile { display: flex; align-items: center; gap: 4px; flex-shrink: 0; }
  .section { padding: 72px 0; }
  .hero { padding: 110px 20px 72px; }
  .reading-body { padding: calc(var(--nav-h) + 52px + 24px) 20px 100px; }
  .page-hero { padding: calc(var(--nav-h) + 48px) 20px 48px; }
  .footer-grid { grid-template-columns: 1fr; gap: 0; }
  .footer-col {
    padding: 0;
    border-bottom: 1px solid var(--border);
  }
  .footer-col-title {
    display: flex; justify-content: space-between; align-items: center;
    padding: 16px 0; margin-bottom: 0; cursor: pointer;
    font-size: 13px; text-transform: none; letter-spacing: 0;
    color: var(--text-dim);
  }
  .footer-col-title::after { content: "+"; font-size: 16px; font-weight: 300; opacity: 0.5; }
  .footer-col.open .footer-col-title::after { content: "−"; }
  .footer-col ul { display: none; padding-bottom: 16px; }
  .footer-col.open ul { display: block; }
  .footer-col ul li a { font-size: 14px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 12px; }
  .footer-legal { gap: 0; }
  .footer-legal a { padding: 2px 10px 2px 0; border-right: none; display: inline-block; }
}
@media (min-width: 769px) {
  .nav-right-mobile { display: contents; }
}

/* ── Logo Images ── */
.nav-logo-img {
  height: 30px; width: 30px;
  border-radius: 50%; object-fit: cover; display: block;
  transition: opacity .2s;
}
.nav-logo-img:hover { opacity: 0.8; }
.footer-logo-img {
  height: 32px; width: 32px;
  border-radius: 50%; object-fit: cover; display: block;
  opacity: 0.5;
}

/* ── 首頁特有元件 ── */
/* 作品卡片 */
.novel-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  min-height: 520px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
@media(max-width:768px){ .novel-card { grid-template-columns: 1fr; } }
.novel-cover {
  background: #000;
  display: flex; align-items: center; justify-content: center;
  min-height: 320px;
  position: relative; overflow: hidden;
}
.novel-cover-inner { text-align: center; z-index: 1; }
.novel-cover-title {
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 700; color: var(--white);
  letter-spacing: -0.04em; line-height: 1.0;
  margin-bottom: 8px;
}
.novel-cover-sub {
  font-size: 13px; color: var(--text-xs);
  letter-spacing: .06em;
}
.novel-info {
  padding: 48px 40px;
  display: flex; flex-direction: column; justify-content: center;
  background: var(--surface);
}
@media(max-width:768px){ .novel-info { padding: 32px 24px; } }
.novel-info-eyebrow {
  font-size: 11px; font-weight: 500; letter-spacing: .12em;
  text-transform: uppercase; color: var(--text-xs);
  margin-bottom: 16px;
}
.novel-info-title {
  font-size: clamp(24px, 3vw, 36px);
  font-weight: 700; color: var(--white);
  letter-spacing: -0.02em; margin-bottom: 16px;
}
.novel-info-desc {
  font-size: 15px; color: var(--text-dim);
  line-height: 1.8; margin-bottom: 32px;
}
.novel-info-meta {
  font-size: 12px; color: var(--text-xs);
  margin-bottom: 28px; letter-spacing: .02em;
}

/* 側欄章節列表 */
.novel-side { display: flex; flex-direction: column; gap: 1px; }
.novel-side-item {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: opacity .2s;
}
.novel-side-item:last-child { border-bottom: none; }
.novel-side-item:hover { opacity: 0.7; }
.novel-side-title { font-size: 13px; font-weight: 500; color: var(--white); margin-bottom: 3px; }
.novel-side-desc { font-size: 12px; color: var(--text-xs); line-height: 1.5; }

/* 統計列 */
.stats-row { display: flex; justify-content: center; gap: 0; }
.stat-item {
  text-align: center; padding: 0 48px;
  border-right: 1px solid var(--border);
}
.stat-item:last-child { border-right: none; }
.stat-num { font-size: clamp(36px, 5vw, 52px); font-weight: 700; color: var(--white); letter-spacing: -0.04em; line-height: 1.0; }
.stat-num span { font-size: .6em; color: var(--text-dim); }
.stat-label { font-size: 12px; color: var(--text-xs); margin-top: 6px; letter-spacing: .04em; }
@media(max-width:768px){
  .stats-row { gap: 0; }
  .stat-item { padding: 0 24px; }
}

/* 近期更新列表 */
.update-list { display: flex; flex-direction: column; gap: 0; }
.update-item {
  display: flex; align-items: center; gap: 20px;
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none; color: var(--text);
  transition: opacity .2s;
}
.update-item:last-child { border-bottom: none; }
.update-item:hover { opacity: 0.65; }
.update-num {
  font-size: 11px; font-weight: 600; letter-spacing: .06em;
  color: var(--text-xs); flex-shrink: 0; width: 24px;
}
.update-info { flex: 1; }
.update-title { font-size: 15px; font-weight: 500; color: var(--white); margin-bottom: 4px; }
.update-meta { font-size: 12px; color: var(--text-xs); }
.update-arrow { font-size: 18px; color: var(--text-xs); flex-shrink: 0; }

/* 精選作品 */
.featured-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
@media(max-width:768px){ .featured-grid { grid-template-columns: 1fr; } }
.featured-item {
  background: var(--bg);
  padding: 32px 28px;
  cursor: pointer;
  transition: background .25s;
  text-decoration: none;
  display: block;
}
.featured-item:hover { background: var(--surface); opacity: 1; }
.featured-icon { font-size: 28px; margin-bottom: 16px; }
.featured-title { font-size: 16px; font-weight: 600; color: var(--white); margin-bottom: 8px; }
.featured-desc { font-size: 13px; color: var(--text-dim); line-height: 1.7; }

/* ── 書櫃頁面 ── */
.bookshelf-page { padding-top: var(--nav-h); }
.book-hero {
  padding: 80px 24px 64px;
  text-align: center;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.book-hero h1 {
  font-size: clamp(36px, 6vw, 64px);
  color: var(--white); margin-bottom: 10px; font-weight: 700; letter-spacing: -0.02em;
}
.book-hero p { font-size: 16px; color: var(--text-dim); margin: 0; }

.book-card {
  display: grid;
  grid-template-columns: 200px 1fr;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 2px;
  transition: border-color .3s;
}
.book-card:hover { border-color: var(--border2); }
@media(max-width:768px){ .book-card { grid-template-columns: 1fr; } }
.book-cover {
  min-height: 220px;
  background: var(--bg2);
  display: flex; align-items: center; justify-content: center;
}
.book-info { padding: 36px 32px; }
@media(max-width:768px){ .book-info { padding: 24px 20px; } }
.book-badges { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 14px; }
.book-title { font-size: clamp(20px, 3vw, 28px); color: var(--white); margin-bottom: 12px; font-weight: 700; letter-spacing: -0.02em; }
.book-desc { font-size: 14px; color: var(--text-dim); line-height: 1.8; margin-bottom: 16px; }
.book-meta { font-size: 12px; color: var(--text-xs); margin-bottom: 20px; }

.chapter-list { margin-top: 20px; }
.chapter-list-title {
  font-size: 11px; font-weight: 600; letter-spacing: .1em;
  text-transform: uppercase; color: var(--text-xs);
  margin-bottom: 8px; padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}
.chapter-item {
  display: flex; align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none; color: var(--text);
  transition: opacity .2s;
  gap: 0;
}
.chapter-item:last-child { border-bottom: none; }
.chapter-item:hover { opacity: 0.65; }
.ch-num {
  font-size: 11px; font-weight: 600; letter-spacing: .06em;
  color: var(--text-xs); width: 56px; flex-shrink: 0;
}
.ch-title { flex: 1; font-size: 14px; font-weight: 400; color: var(--white); }
.ch-status { font-size: 12px; color: var(--text-xs); flex-shrink: 0; }

/* ── 章節目錄彈出層 ── */
/* TOC overlay — 不需要了，由 panel 本身覆蓋 */
.toc-overlay {
  display: none;
}

/* TOC panel — Apple 官網風格：從頂部向下展開全螢幕 */
.toc-panel {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 100vh;
  z-index: 1101;
  background: rgba(0,0,0,0.97);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  overflow-y: auto;
  overflow-x: hidden;
  transform: translateY(-100%);
  transition: transform .35s cubic-bezier(.4,0,.2,1);
  padding: 0 0 60px;
}
.toc-panel.open {
  transform: translateY(0);
}
@keyframes tocItemIn {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: none; }
}
.toc-panel.open .toc-item {
  animation: tocItemIn .3s cubic-bezier(.4,0,.2,1) both;
}
.toc-panel.open .toc-item:nth-child(1)  { animation-delay: .04s; }
.toc-panel.open .toc-item:nth-child(2)  { animation-delay: .07s; }
.toc-panel.open .toc-item:nth-child(3)  { animation-delay: .10s; }
.toc-panel.open .toc-item:nth-child(4)  { animation-delay: .13s; }
.toc-panel.open .toc-item:nth-child(5)  { animation-delay: .16s; }
.toc-panel.open .toc-item:nth-child(6)  { animation-delay: .19s; }
.toc-panel.open .toc-item:nth-child(7)  { animation-delay: .22s; }
.toc-panel.open .toc-item:nth-child(8)  { animation-delay: .25s; }
.toc-panel.open .toc-item:nth-child(9)  { animation-delay: .28s; }
.toc-panel.open .toc-item:nth-child(10) { animation-delay: .31s; }
.toc-panel.open .toc-item:nth-child(11) { animation-delay: .34s; }
.toc-panel.open .toc-item:nth-child(12) { animation-delay: .37s; }
.toc-panel.open .toc-item:nth-child(13) { animation-delay: .40s; }
.toc-panel.open .toc-item:nth-child(14) { animation-delay: .43s; }
.toc-panel.open .toc-item:nth-child(15) { animation-delay: .46s; }
.toc-panel.open .toc-item:nth-child(16) { animation-delay: .49s; }

.toc-header {
  position: sticky; top: 0; z-index: 2;
  background: rgba(0,0,0,0.95);
  border-bottom: 1px solid rgba(255,255,255,0.07);
  padding: calc(var(--nav-h) + 8px) 32px 16px;
  display: flex; align-items: center; justify-content: space-between;
}
.toc-header-title {
  font-size: 11px; font-weight: 600; letter-spacing: .14em;
  text-transform: uppercase; color: rgba(240,240,240,0.35);
}
.toc-close {
  width: 32px; height: 32px;
  background: rgba(255,255,255,0.08);
  border: none; border-radius: 50%; cursor: pointer;
  color: #f0f0f0; font-size: 14px;
  display: flex; align-items: center; justify-content: center;
  transition: background .2s;
}
.toc-close:hover { background: rgba(255,255,255,0.15); }

/* 右上角固定 X 按鈕 */
.toc-close-fixed {
  position: fixed;
  top: calc((var(--nav-h) - 32px) / 2);
  right: 18px;
  z-index: 1102;
  width: 32px; height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  color: rgba(240,240,240,0.7);
  font-size: 18px;
  display: none;
  align-items: center; justify-content: center;
  transition: color .2s;
}
.toc-close-fixed:hover { color: #fff; }
.toc-close-fixed.visible { display: flex; }

.toc-part-label {
  font-size: 11px; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--accent-gold);
  padding: 28px 32px 10px;
}
.toc-item {
  display: flex; align-items: center;
  padding: 18px 32px;
  text-decoration: none;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  transition: opacity .15s;
  gap: 0;
}
.toc-item:hover { opacity: 0.65; background: none; }
.toc-item.toc-active { opacity: 1; }
.toc-item-num {
  font-size: 12px; font-weight: 500; letter-spacing: .04em;
  color: rgba(240,240,240,0.28); width: 56px; flex-shrink: 0;
}
.toc-item-title {
  flex: 1;
  font-size: clamp(22px, 5vw, 30px);
  color: rgba(240,240,240,0.85);
  font-weight: 600;
  letter-spacing: -0.02em;
}
.toc-item.toc-active .toc-item-title { color: var(--accent-gold); }
.toc-item-arrow {
  font-size: 20px; color: rgba(240,240,240,0.2);
  transition: transform .2s, color .2s;
}
.toc-item:hover .toc-item-arrow { color: rgba(240,240,240,0.5); transform: translateX(4px); }

/* ── 日間閱讀模式修復 ──
   閱讀頁曾使用固定的深色文字／背景值，切換 light class 後未隨主題變數反轉。 */
body.light .reading-content {
  color: rgba(26,26,26,0.78);
}
body.light .reading-content p {
  color: inherit;
}
body.light .reading-toolbar {
  background: rgba(248,248,246,0.92);
  border-bottom-color: rgba(0,0,0,0.10);
  box-shadow: 0 8px 22px rgba(0,0,0,0.035);
}
body.light .toolbar-btn.primary:hover {
  background: rgba(0,0,0,0.08);
}
body.light .progress-fill {
  background: rgba(26,26,26,0.38);
}
body.light .music-bar {
  background: rgba(248,248,246,0.94);
  border-top-color: rgba(0,0,0,0.10);
}
body.light .mb-progress-fill {
  background: rgba(26,26,26,0.48);
}
body.light .mb-btn.play:hover {
  background: rgba(0,0,0,0.10);
}
body.light .toc-panel,
body.light .toc-header {
  background: rgba(248,248,246,0.98);
  border-color: rgba(0,0,0,0.09);
}
body.light .toc-header-title,
body.light .toc-item-num {
  color: rgba(26,26,26,0.42);
}
body.light .toc-item {
  border-bottom-color: rgba(0,0,0,0.07);
}
body.light .toc-item-title {
  color: rgba(26,26,26,0.88);
}
body.light .toc-item-arrow {
  color: rgba(26,26,26,0.26);
}
body.light .toc-close {
  background: rgba(0,0,0,0.07);
  color: rgba(26,26,26,0.80);
}
body.light .toc-close-fixed {
  color: rgba(26,26,26,0.74);
}
body.light .toc-part-label {
  color: #917433;
}
body.light.part3-reading .reading-body::before {
  background: radial-gradient(ellipse at center top,rgba(90,160,226,.08),transparent 70%);
}
body.light .part3-source-status {
  background: rgba(90,160,226,.065);
  border-color: rgba(60,128,196,.26);
  color: rgba(20,45,70,.80);
}
body.light .part3-source-detail {
  color: rgba(20,45,70,.58);
}
body.light .part3-source-status.is-warning {
  background: rgba(224,84,80,.075);
  border-color: rgba(190,64,60,.30);
}
body.light .part3-source-status.is-warning .part3-source-name,
body.light .part3-source-status.is-warning .part3-countdown {
  color: #a73e3b;
}
body.light .part3-source-status.is-warning .part3-source-detail {
  color: rgba(108,42,39,.62);
}

/* ── 導覽列日夜切換控制 ── */
.nav-theme-toggle {
  width:32px; height:32px;
  display:inline-flex; align-items:center; justify-content:center;
  border:1px solid var(--border); border-radius:50%;
  background:var(--surface); color:var(--text-dim);
  cursor:pointer; font-size:15px; line-height:1;
  -webkit-tap-highlight-color:transparent;
  transition:background .2s,color .2s,border-color .2s,transform .2s;
}
.nav-theme-toggle:hover,
.nav-theme-toggle:active { background:var(--surface2); color:var(--white); transform:scale(.95); }
body.light .nav-theme-toggle {
  background:rgba(0,0,0,.045);
  border-color:rgba(0,0,0,.12);
  color:rgba(20,20,20,.78);
}
body.light .nav-theme-toggle:hover,
body.light .nav-theme-toggle:active { background:rgba(0,0,0,.09); color:#000; }
body.light .nav-hamburger span { background:rgba(26,26,26,.76); }

/* 手機版的 !important 深色覆寫需由日間模式再覆蓋一次。 */
@media(max-width:768px){
  body.light .nav-menu.open {
    background:rgba(248,248,246,.985) !important;
    backdrop-filter:blur(40px) !important;
    -webkit-backdrop-filter:blur(40px) !important;
  }
  body.light .nav-menu.open li { border-bottom-color:rgba(0,0,0,.07); }
  body.light .nav-menu.open li a { color:rgba(20,20,20,.88); }
  body.light .nav-menu.open li a::after { color:rgba(20,20,20,.25); }
  body.light .nav-menu.open li a:hover,
  body.light .nav-menu.open li a:active { color:#000; }
}

/* 日間模式下的主要操作維持深色底與白字，避免主按鈕文字消失。 */
body.light .btn-primary {
  background:#171717;
  border-color:#171717;
  color:#fff;
}
body.light .btn-primary:hover,
body.light .btn-primary:active {
  background:#323232;
  border-color:#323232;
  color:#fff;
}