:root {
  --font-serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "STSong", "Iowan Old Style", serif;
  --font-sans: "Avenir Next", "SF Pro Display", "PingFang SC", "Helvetica Neue", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", "Menlo", monospace;
  --reader-font-size: 18px;
  --reader-line-height: 1.95;
  --reader-width: 760px;
  --dock-height: 78px;
  --shadow-soft: 0 12px 30px rgba(56, 44, 23, 0.08);
  --shadow-panel: 0 18px 36px rgba(50, 36, 12, 0.09);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.72), transparent 28%),
    linear-gradient(180deg, rgba(234, 224, 203, 0.36), transparent 22%),
    var(--app-bg);
  color: var(--ink);
}

body.body-modal-open {
  overflow: hidden;
}

body.theme-paper {
  --app-bg: #efe7d6;
  --app-panel: rgba(250, 246, 237, 0.9);
  --app-panel-strong: #fbf7ee;
  --app-panel-muted: rgba(245, 238, 223, 0.72);
  --stroke: rgba(111, 89, 54, 0.18);
  --ink: #2f2416;
  --ink-soft: #695841;
  --accent: #315847;
  --accent-strong: #1e4134;
  --accent-wash: rgba(49, 88, 71, 0.12);
  --quote-bg: rgba(114, 93, 56, 0.07);
  --table-head: rgba(76, 101, 85, 0.11);
}

body.theme-sepia {
  --app-bg: #e5d4b5;
  --app-panel: rgba(247, 238, 218, 0.9);
  --app-panel-strong: #f9f1de;
  --app-panel-muted: rgba(240, 224, 191, 0.74);
  --stroke: rgba(124, 81, 40, 0.2);
  --ink: #392411;
  --ink-soft: #6c4a27;
  --accent: #7b4e1f;
  --accent-strong: #61370d;
  --accent-wash: rgba(123, 78, 31, 0.12);
  --quote-bg: rgba(123, 78, 31, 0.08);
  --table-head: rgba(123, 78, 31, 0.11);
}

body.theme-midnight {
  --app-bg: #11161c;
  --app-panel: rgba(25, 32, 41, 0.92);
  --app-panel-strong: #1a212b;
  --app-panel-muted: rgba(28, 36, 46, 0.86);
  --stroke: rgba(195, 207, 219, 0.15);
  --ink: #e6edf3;
  --ink-soft: #9fafc0;
  --accent: #7dbb9b;
  --accent-strong: #9cd5b7;
  --accent-wash: rgba(125, 187, 155, 0.12);
  --quote-bg: rgba(125, 187, 155, 0.09);
  --table-head: rgba(125, 187, 155, 0.08);
  --shadow-soft: 0 12px 30px rgba(0, 0, 0, 0.28);
  --shadow-panel: 0 18px 36px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

img {
  max-width: 100%;
  display: block;
}

button,
input {
  font: inherit;
}

.hidden {
  display: none !important;
}

.eyebrow {
  margin: 0 0 4px;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.app-shell {
  position: relative;
  min-height: 100vh;
}

.app-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(8, 12, 16, 0.36);
  backdrop-filter: blur(4px);
  z-index: 35;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: calc(env(safe-area-inset-top, 0px) + 14px) 20px 14px;
  background: color-mix(in srgb, var(--app-bg) 72%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--stroke);
}

.topbar__left,
.topbar__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.topbar__titles h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
}

.ghost-button,
.secondary-button,
.primary-button,
.tool-chip,
.dock-button,
.theme-chip,
.icon-button {
  border: 1px solid var(--stroke);
  background: var(--app-panel-muted);
  color: var(--ink);
  border-radius: 999px;
  padding: 10px 14px;
  cursor: pointer;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.ghost-button:hover,
.secondary-button:hover,
.primary-button:hover,
.theme-chip:hover,
.icon-button:hover {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--accent) 34%, var(--stroke));
}

.primary-button {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #f7f6f2;
  border-color: transparent;
}

.secondary-button {
  background: var(--app-panel);
}

.tool-chip,
.dock-button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.icon-button {
  width: 42px;
  height: 42px;
  padding: 0;
  font-size: 24px;
  line-height: 1;
}

.app-layout {
  display: grid;
  grid-template-columns: minmax(300px, 360px) minmax(0, 1fr);
  gap: 24px;
  padding: 20px;
  align-items: start;
}

.book-rail {
  position: sticky;
  top: 92px;
  display: grid;
  gap: 18px;
}

.cover-card,
.rail-panel,
.chapter-shell,
.drawer,
.search-overlay__panel {
  background: var(--app-panel);
  border: 1px solid var(--stroke);
  box-shadow: var(--shadow-panel);
}

.cover-card,
.rail-panel,
.chapter-shell {
  border-radius: 28px;
}

.cover-card {
  overflow: hidden;
}

.cover-card__art {
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.55), transparent 55%),
    linear-gradient(135deg, color-mix(in srgb, var(--accent) 16%, transparent), transparent),
    var(--app-panel-strong);
  padding: 26px;
  border-bottom: 1px solid var(--stroke);
}

.cover-card__art img {
  width: 100%;
  border-radius: 20px;
  box-shadow: var(--shadow-soft);
}

.cover-card__body {
  padding: 22px;
}

.cover-card__body h2 {
  margin: 0 0 8px;
  font-size: 24px;
  line-height: 1.25;
}

.cover-card__subtitle,
.cover-card__description,
.setting-value,
.chapter-subtitle,
.chapter-stats,
.version-row,
.search-meta {
  color: var(--ink-soft);
}

.cover-card__actions {
  display: flex;
  gap: 10px;
  margin-top: 18px;
}

.version-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 13px;
}

.rail-panel {
  padding: 18px;
}

.rail-panel__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.rail-panel__header h3 {
  margin: 0;
}

.overall-progress,
.reading-progress {
  height: 6px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  overflow: hidden;
}

.overall-progress span,
.reading-progress span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 44%, #ffffff));
  border-radius: inherit;
}

.rail-toc,
.drawer__body {
  display: grid;
  gap: 12px;
}

.toc-section {
  display: grid;
  gap: 10px;
}

.toc-section__title {
  margin: 6px 0 0;
  color: var(--ink-soft);
  font-size: 13px;
  letter-spacing: 0.06em;
}

.toc-item {
  width: 100%;
  display: grid;
  gap: 8px;
  text-align: left;
  padding: 12px 14px;
  border-radius: 18px;
  border: 1px solid var(--stroke);
  background: var(--app-panel-strong);
  color: var(--ink);
}

.toc-item.is-active {
  border-color: color-mix(in srgb, var(--accent) 36%, var(--stroke));
  background: color-mix(in srgb, var(--accent-wash) 78%, var(--app-panel-strong));
}

.toc-item__title {
  font-weight: 700;
}

.toc-item__meta {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-size: 12px;
  color: var(--ink-soft);
}

.reader-column {
  min-width: 0;
}

.chapter-shell {
  margin: 0 auto 40px;
  max-width: calc(var(--reader-width) + 96px);
  padding: 30px 28px 28px;
}

.chapter-meta__top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.section-pill {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--accent-wash);
  color: var(--accent-strong);
  font-size: 12px;
  font-weight: 700;
}

.chapter-order {
  color: var(--ink-soft);
  font-size: 13px;
}

.chapter-meta h2 {
  margin: 14px 0 8px;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.12;
}

.chapter-subtitle {
  margin: 0 0 10px;
  font-size: 18px;
}

.chapter-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  font-size: 13px;
}

.chapter-tool-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.tool-chip {
  padding: 9px 14px;
  background: var(--app-panel-strong);
}

.tool-chip.is-active,
.dock-button.is-active {
  background: var(--accent);
  color: #f8f4ea;
  border-color: transparent;
}

.reading-progress {
  margin: 22px 0 30px;
}

.chapter-content {
  max-width: var(--reader-width);
  margin: 0 auto;
  font-family: var(--font-serif);
  font-size: var(--reader-font-size);
  line-height: var(--reader-line-height);
  letter-spacing: 0.01em;
}

.chapter-content h2,
.chapter-content h3,
.chapter-content h4 {
  font-family: var(--font-sans);
  line-height: 1.3;
  margin: 2.1em 0 0.8em;
}

.chapter-content h2 {
  font-size: 1.5em;
}

.chapter-content h3 {
  font-size: 1.18em;
}

.chapter-content p,
.chapter-content li {
  color: var(--ink);
}

.chapter-content p {
  margin: 0 0 1.18em;
}

.annotatable-block {
  position: relative;
  transition: background-color 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

.chapter-content.note-mode .annotatable-block {
  cursor: pointer;
}

.chapter-content.note-mode .annotatable-block:hover,
.chapter-content.note-mode .annotatable-block:active {
  background: color-mix(in srgb, var(--accent-wash) 88%, transparent);
  border-radius: 14px;
}

.annotatable-block.has-note {
  background: color-mix(in srgb, var(--accent-wash) 78%, transparent);
  border-radius: 14px;
}

.annotatable-block.has-note::after {
  content: "";
  position: absolute;
  top: 0.55em;
  right: -8px;
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--app-panel-strong) 86%, transparent);
}

.annotatable-block.is-flashed {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 28%, transparent);
}

.term-trigger {
  border: none;
  padding: 0;
  margin: 0;
  background: none;
  color: inherit;
  font: inherit;
  border-bottom: 1.5px dashed color-mix(in srgb, var(--accent) 68%, transparent);
  cursor: pointer;
}

.term-trigger:hover {
  color: var(--accent-strong);
}

.chapter-content strong {
  color: var(--accent-strong);
}

.chapter-content hr {
  border: none;
  border-top: 1px solid var(--stroke);
  margin: 2em 0;
}

.chapter-content blockquote {
  margin: 1.8em 0;
  padding: 1.1em 1.2em;
  background: var(--quote-bg);
  border-left: 4px solid color-mix(in srgb, var(--accent) 55%, transparent);
  border-radius: 0 18px 18px 0;
}

.chapter-content code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  padding: 0.14em 0.34em;
  border-radius: 0.4em;
  background: color-mix(in srgb, var(--accent-wash) 55%, transparent);
}

.chapter-content pre {
  overflow: auto;
  padding: 1em;
  border-radius: 18px;
  background: color-mix(in srgb, var(--app-panel-strong) 85%, transparent);
  border: 1px solid var(--stroke);
}

.chapter-content pre code {
  background: transparent;
  padding: 0;
}

.math-block,
.math-inline {
  overflow-x: auto;
  overflow-y: hidden;
}

.math-block {
  margin: 1.15em 0;
  padding: 0.35em 0.2em;
  text-align: center;
}

.math-inline {
  display: inline-block;
  max-width: 100%;
  vertical-align: middle;
}

.math-rendered .katex {
  font-size: 1.04em;
}

.math-block.math-rendered .katex-display {
  margin: 0;
}

.math-render-failed {
  font-family: var(--font-mono, "SFMono-Regular", ui-monospace, monospace);
  font-size: 0.95em;
  white-space: pre-wrap;
}

.figure-block {
  margin: 1.8em 0 0.7em;
}

.reader-image {
  width: 100%;
  border-radius: 18px;
  border: 1px solid var(--stroke);
  box-shadow: var(--shadow-soft);
  cursor: zoom-in;
}

.figure-caption {
  margin-top: 0;
  font-size: 0.9em;
  text-align: center;
  color: var(--ink-soft);
}

.table-wrap {
  overflow-x: auto;
  margin: 1.8em 0;
  border: 1px solid var(--stroke);
  border-radius: 18px;
  background: var(--app-panel-strong);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 680px;
}

.data-table th,
.data-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--stroke);
  vertical-align: top;
}

.data-table th {
  position: sticky;
  top: 0;
  background: var(--table-head);
  font-family: var(--font-sans);
  text-align: left;
}

.chapter-nav {
  max-width: var(--reader-width);
  margin: 34px auto 6px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.drawer {
  position: fixed;
  top: 0;
  bottom: 0;
  width: min(88vw, 380px);
  z-index: 40;
  overflow: auto;
  padding: max(env(safe-area-inset-top, 0px), 12px) 14px 18px;
  transform: translateX(-110%);
  transition: transform 220ms ease;
}

.drawer--toc {
  left: 0;
  border-right: 1px solid var(--stroke);
}

.drawer--settings {
  right: 0;
  transform: translateX(110%);
  border-left: 1px solid var(--stroke);
}

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

.drawer__header,
.search-overlay__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 10px 6px 14px;
  border-bottom: 1px solid var(--stroke);
  margin-bottom: 12px;
}

.drawer__title,
.search-overlay__header h2 {
  margin: 0;
}

.settings-panel {
  padding: 4px 6px 18px;
}

.settings-group {
  display: grid;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--stroke);
}

.settings-group h3 {
  margin: 0;
}

.theme-options {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.theme-chip.is-active {
  background: var(--accent);
  color: #f8f4ea;
  border-color: transparent;
}

.search-overlay,
.lightbox,
.panel-overlay {
  position: fixed;
  inset: 0;
  z-index: 45;
  background: rgba(12, 17, 22, 0.52);
  backdrop-filter: blur(10px);
}

.search-overlay {
  display: grid;
  place-items: center;
  padding: 24px;
}

.panel-overlay {
  display: grid;
  place-items: end center;
  padding: 24px;
  overflow-y: auto;
}

.search-overlay__panel {
  width: min(920px, 100%);
  max-height: min(80vh, 900px);
  overflow: auto;
  border-radius: 28px;
  padding: 20px;
}

.panel-sheet {
  position: relative;
  z-index: 1;
  width: min(920px, 100%);
  max-height: min(84vh, 920px);
  overflow: auto;
  border-radius: 28px;
  padding: 20px;
  background: var(--app-panel);
  border: 1px solid var(--stroke);
  box-shadow: var(--shadow-panel);
}

.panel-sheet--compact {
  width: min(640px, 100%);
}

.panel-sheet__header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--stroke);
}

.panel-sheet__header h2 {
  margin: 0;
}

.panel-sheet__header .icon-button {
  position: relative;
  z-index: 2;
}

.panel-sheet__meta {
  margin: 16px 0;
  color: var(--ink-soft);
}

.panel-search-box {
  margin-top: 18px;
}

.notes-list,
.glossary-list,
.reference-card-list {
  display: grid;
  gap: 14px;
}

.note-card,
.glossary-item,
.reference-card,
.term-card,
.note-context {
  border: 1px solid var(--stroke);
  border-radius: 22px;
  background: var(--app-panel-strong);
}

.note-card {
  padding: 16px;
}

.note-card__anchor,
.note-card__text,
.note-card__time {
  margin: 0;
}

.note-card__anchor {
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.7;
}

.note-card__text {
  margin-top: 10px;
  white-space: pre-wrap;
  font-family: var(--font-serif);
  line-height: 1.8;
}

.note-card__time {
  margin-top: 10px;
  font-size: 12px;
  color: var(--ink-soft);
}

.note-card__actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
}

.glossary-item {
  width: 100%;
  text-align: left;
  padding: 15px 16px;
}

.glossary-item.is-current {
  border-color: color-mix(in srgb, var(--accent) 34%, var(--stroke));
  background: color-mix(in srgb, var(--accent-wash) 72%, var(--app-panel-strong));
}

.glossary-item__top,
.glossary-item__meta,
.term-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  justify-content: space-between;
}

.glossary-item__top strong {
  font-size: 16px;
}

.glossary-item__top span,
.glossary-item__meta,
.reference-card__head .eyebrow {
  color: var(--ink-soft);
}

.glossary-item p {
  margin: 10px 0 0;
  line-height: 1.75;
}

.glossary-item__meta {
  margin-top: 10px;
  font-size: 13px;
}

.reference-card {
  overflow: hidden;
}

.reference-card__head {
  padding: 18px 18px 0;
}

.reference-card__head h3 {
  margin: 0;
}

.reference-card__body {
  padding: 10px 18px 18px;
  font-family: var(--font-serif);
  line-height: 1.8;
}

.reference-card__body h2,
.reference-card__body h3,
.reference-card__body h4 {
  margin-top: 1.2em;
}

.term-card {
  margin-top: 18px;
  padding: 18px;
}

.term-pill {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--accent-wash);
  color: var(--accent-strong);
  font-size: 13px;
  font-weight: 700;
}

.term-pill.is-muted {
  background: var(--app-panel-muted);
  color: var(--ink-soft);
}

.term-card__definition {
  margin: 14px 0 0;
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: 1.86;
}

.note-context {
  margin-top: 18px;
  padding: 14px 16px;
  color: var(--ink-soft);
  font-family: var(--font-serif);
  line-height: 1.8;
}

.editor-field {
  display: grid;
  gap: 8px;
  margin-top: 16px;
}

.editor-field textarea {
  width: 100%;
  resize: vertical;
  min-height: 180px;
  padding: 14px 16px;
  border: 1px solid var(--stroke);
  border-radius: 18px;
  background: var(--app-panel-strong);
  color: var(--ink);
  font-family: var(--font-serif);
  line-height: 1.75;
}

.composer-actions {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 16px;
}

.search-box {
  display: grid;
  gap: 8px;
}

.search-box input {
  border: 1px solid var(--stroke);
  border-radius: 18px;
  padding: 14px 16px;
  background: var(--app-panel-strong);
  color: var(--ink);
}

.search-results {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.search-result {
  border: 1px solid var(--stroke);
  border-radius: 20px;
  padding: 14px 16px;
  background: var(--app-panel-strong);
  text-align: left;
}

.search-result h3 {
  margin: 0 0 6px;
}

.search-result p {
  margin: 0;
  color: var(--ink-soft);
}

.search-result mark {
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  color: inherit;
}

.lightbox {
  display: grid;
  place-items: center;
  gap: 16px;
  padding: 24px;
}

.lightbox img {
  max-width: min(1100px, 100%);
  max-height: calc(100vh - 120px);
  border-radius: 24px;
  box-shadow: 0 28px 48px rgba(0, 0, 0, 0.35);
}

.lightbox__caption {
  max-width: 72ch;
  color: #f3efe5;
  text-align: center;
  margin: 0;
}

.lightbox__close {
  position: absolute;
  top: calc(env(safe-area-inset-top, 0px) + 18px);
  right: 18px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(env(safe-area-inset-bottom, 0px) + var(--dock-height) + 10px);
  transform: translateX(-50%);
  z-index: 50;
  max-width: min(88vw, 520px);
  padding: 12px 16px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 86%, #101418);
  color: #f7f7f3;
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.22);
}

.reader-dock {
  position: fixed;
  left: max(10px, calc(env(safe-area-inset-left, 0px) + 10px));
  right: max(10px, calc(env(safe-area-inset-right, 0px) + 10px));
  bottom: calc(env(safe-area-inset-bottom, 0px) + 10px);
  z-index: 60;
  display: none;
  gap: 10px;
  width: auto;
  padding: 10px;
  border: 1px solid var(--stroke);
  border-radius: 999px;
  background: color-mix(in srgb, var(--app-panel) 92%, transparent);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow-panel);
}

body.body-modal-open .reader-dock {
  opacity: 0;
  pointer-events: none;
}

.dock-button {
  flex: 1 1 0;
  justify-content: center;
  padding: 11px 10px;
  background: var(--app-panel-strong);
}

@media (max-width: 959px) {
  .app-layout {
    grid-template-columns: 1fr;
    padding: 16px 14px 28px;
  }

  .book-rail {
    display: none;
  }

  .topbar {
    padding-inline: 14px;
  }

  .topbar__titles h1 {
    font-size: 16px;
  }

  .topbar__actions {
    gap: 6px;
  }

  .ghost-button {
    padding: 8px 10px;
    font-size: 13px;
  }

  .chapter-shell {
    padding: 22px 16px calc(var(--dock-height) + 18px);
    border-radius: 22px;
  }

  .chapter-content {
    font-size: calc(var(--reader-font-size) - 1px);
  }

  .chapter-nav {
    flex-direction: column;
  }

  .chapter-tool-row {
    flex-wrap: nowrap;
    overflow-x: auto;
    margin-top: 16px;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
  }

  .reader-dock {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .panel-overlay,
  .search-overlay {
    padding: 12px;
  }

  .panel-sheet,
  .search-overlay__panel {
    border-radius: 24px;
    max-height: min(88vh, 920px);
  }

  .note-card__actions,
  .composer-actions {
    flex-direction: column;
  }
}