:root {
  --paper: #f5f1e8;
  --paper-deep: #ebe4d6;
  --surface: rgba(255, 253, 248, 0.86);
  --surface-solid: #fffdf8;
  --ink: #28231d;
  --muted: #81786b;
  --line: rgba(65, 53, 38, 0.14);
  --accent: #9a6a2f;
  --accent-strong: #7b4e1e;
  --reader-font-size: 18px;
  --reader-line-height: 2.05;
  --shadow: 0 18px 50px rgba(72, 52, 29, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--paper);
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  min-height: 100%;
  margin: 0;
  background:
    radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.75), transparent 32rem),
    var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  transition: background-color 180ms ease, color 180ms ease;
}

body[data-theme="dark"] {
  --paper: #1b1b1a;
  --paper-deep: #252421;
  --surface: rgba(38, 37, 33, 0.92);
  --surface-solid: #262521;
  --ink: #e9e2d5;
  --muted: #a69c8e;
  --line: rgba(235, 224, 204, 0.15);
  --accent: #d2a264;
  --accent-strong: #e2b676;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.2);
  background:
    radial-gradient(circle at 12% 0%, rgba(76, 66, 47, 0.16), transparent 32rem),
    var(--paper);
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
  font: inherit;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent);
  outline-offset: 3px;
}

[hidden] {
  display: none !important;
}

.reader-app {
  min-height: 100vh;
}

.topbar {
  position: sticky;
  z-index: 5;
  top: 0;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  min-height: 64px;
  padding: max(10px, env(safe-area-inset-top)) clamp(16px, 4vw, 32px) 10px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  color: inherit;
  text-decoration: none;
}

.brand strong {
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.brand-kicker,
.eyebrow {
  margin: 0;
  color: var(--accent);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.icon-button,
.text-button,
.small-button,
.close-button {
  border: 0;
  background: transparent;
  cursor: pointer;
}

.icon-button {
  justify-self: start;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 40px;
  padding: 7px 9px;
  color: var(--muted);
  font-size: 13px;
}

.icon-button:last-child {
  justify-self: end;
}

.menu-lines {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 16px;
}

.menu-lines i {
  display: block;
  width: 16px;
  height: 1px;
  background: currentColor;
}

main {
  width: min(100%, 900px);
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 36px) 64px;
}

.library-view {
  padding-top: clamp(36px, 8vw, 76px);
}

.library-intro {
  padding: clamp(26px, 6vw, 56px) clamp(22px, 6vw, 60px) clamp(28px, 6vw, 52px);
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.library-intro h1 {
  margin: 12px 0 12px;
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-size: clamp(32px, 7vw, 54px);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.library-summary {
  max-width: 30em;
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.primary-button {
  min-height: 44px;
  margin-top: 24px;
  padding: 0 20px;
  border: 1px solid var(--accent-strong);
  border-radius: 999px;
  background: var(--accent-strong);
  color: #fffaf1;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
}

.primary-button:active,
.nav-button:active,
.chapter-card:active {
  transform: translateY(1px);
}

.chapter-section {
  padding: clamp(34px, 8vw, 64px) 0 0;
}

.section-heading,
.drawer-header,
.reader-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.section-heading {
  padding: 0 4px 14px;
  border-bottom: 1px solid var(--line);
}

.section-heading h2,
.drawer-header h2 {
  margin: 6px 0 0;
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-size: 22px;
  letter-spacing: 0.06em;
}

.chapter-count {
  color: var(--muted);
  font-size: 13px;
}

.chapter-list {
  display: grid;
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-top: 0;
  border-radius: 0 0 14px 14px;
  background: var(--line);
}

.chapter-card {
  display: grid;
  grid-template-columns: 48px 1fr auto;
  align-items: center;
  gap: 16px;
  min-height: 76px;
  padding: 13px 16px;
  border: 0;
  background: var(--surface-solid);
  color: inherit;
  text-align: left;
  cursor: pointer;
  transition: background-color 160ms ease, padding-left 160ms ease;
}

.chapter-card:hover {
  padding-left: 20px;
  background: color-mix(in srgb, var(--surface-solid) 80%, var(--accent) 20%);
}

.chapter-number {
  color: var(--accent);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 12px;
  letter-spacing: 0.12em;
}

.chapter-name {
  overflow: hidden;
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-size: 16px;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chapter-meta {
  color: var(--muted);
  font-size: 12px;
  white-space: nowrap;
}

.state-card,
.reading-state {
  padding: 26px 18px;
  color: var(--muted);
  font-size: 14px;
  text-align: center;
}

.reader-view {
  padding: 12px 0 48px;
}

.reader-toolbar {
  min-height: 52px;
  border-bottom: 1px solid var(--line);
}

.text-button {
  padding: 10px 0;
  color: var(--accent-strong);
  cursor: pointer;
  font-size: 14px;
}

.chapter-progress {
  color: var(--muted);
  font-size: 12px;
}

.font-controls {
  display: flex;
  gap: 3px;
}

.small-button {
  min-width: 35px;
  min-height: 35px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  cursor: pointer;
  font-size: 12px;
}

.chapter-article {
  min-height: 45vh;
  padding: clamp(28px, 7vw, 72px) 0 56px;
}

.chapter-content {
  max-width: 760px;
  margin: 0 auto;
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", serif;
  font-size: var(--reader-font-size);
  line-height: var(--reader-line-height);
  letter-spacing: 0.025em;
}

.chapter-content > h1 {
  margin: 0 0 40px;
  color: var(--ink);
  font-size: clamp(28px, 6vw, 40px);
  line-height: 1.35;
  letter-spacing: 0.08em;
}

.chapter-content > h2,
.chapter-content > h3 {
  margin: 2.2em 0 0.8em;
  font-size: 1.25em;
  line-height: 1.5;
}

.chapter-content p {
  margin: 0 0 1.05em;
  text-align: left;
  text-wrap: pretty;
}

.chapter-content blockquote {
  margin: 1.4em 0;
  padding: 0.3em 0 0.3em 1em;
  border-left: 3px solid var(--accent);
  color: color-mix(in srgb, var(--ink) 78%, var(--muted));
}

.chapter-content blockquote p {
  margin-bottom: 0.55em;
}

.chapter-content blockquote p:last-child {
  margin-bottom: 0;
}

.chapter-content hr {
  margin: 2.4em auto;
  border: 0;
  border-top: 1px solid var(--line);
}

.chapter-content ul,
.chapter-content ol {
  margin: 1em 0;
  padding-left: 1.5em;
}

.chapter-content li {
  margin: 0.35em 0;
}

.chapter-navigation {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 8px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.nav-button {
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface-solid);
  color: var(--ink);
  cursor: pointer;
  font-size: 13px;
}

.nav-button-center {
  color: var(--accent-strong);
}

.nav-button:disabled {
  cursor: not-allowed;
  opacity: 0.38;
}

.reader-footer {
  padding: 26px 16px max(28px, env(safe-area-inset-bottom));
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-align: center;
}

.drawer-backdrop {
  position: fixed;
  z-index: 9;
  inset: 0;
  background: rgba(22, 18, 12, 0.34);
}

.chapter-drawer {
  position: fixed;
  z-index: 10;
  top: 0;
  bottom: 0;
  left: 0;
  display: flex;
  flex-direction: column;
  width: min(88vw, 390px);
  padding: max(22px, env(safe-area-inset-top)) 18px max(18px, env(safe-area-inset-bottom));
  border-right: 1px solid var(--line);
  background: var(--surface-solid);
  box-shadow: 18px 0 60px rgba(31, 24, 15, 0.16);
  transform: translateX(-105%);
  transition: transform 220ms ease;
}

.chapter-drawer.is-open {
  transform: translateX(0);
}

.drawer-header {
  flex: 0 0 auto;
  padding: 4px 4px 18px;
  border-bottom: 1px solid var(--line);
}

.close-button {
  width: 40px;
  height: 40px;
  color: var(--muted);
  cursor: pointer;
  font-size: 26px;
  line-height: 1;
}

.drawer-list {
  overflow-y: auto;
  padding: 8px 0;
}

.drawer-chapter {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 10px;
  width: 100%;
  padding: 13px 10px;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  color: inherit;
  cursor: pointer;
  text-align: left;
}

.drawer-chapter.is-current {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
}

.drawer-chapter-number {
  color: var(--accent);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 12px;
}

.drawer-chapter-name {
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-size: 14px;
  line-height: 1.5;
}

@media (min-width: 680px) {
  .topbar {
    min-height: 72px;
  }

  .chapter-card {
    min-height: 84px;
    padding-inline: 22px;
  }

  .chapter-content p {
    text-align: justify;
    text-justify: inter-ideograph;
  }
}

@media (max-width: 430px) {
  .button-label {
    display: none;
  }

  .chapter-card {
    grid-template-columns: 36px 1fr;
    gap: 10px;
  }

  .chapter-meta {
    grid-column: 2;
    margin-top: -8px;
  }

  .chapter-content > h1 {
    margin-bottom: 30px;
  }

  .chapter-navigation {
    gap: 5px;
  }

  .nav-button {
    padding-inline: 8px;
    font-size: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}