:root {
  --paper: #f7f5ef;
  --paper-deep: #eeeae0;
  --white: #fffefa;
  --ink: #242c2b;
  --ink-soft: #465351;
  --muted: #77817e;
  --muted-light: #a2aaa5;
  --line: #dddcd4;
  --line-soft: #e9e7df;
  --teal: #2c716b;
  --teal-soft: #e1efea;
  --coral: #b85c4d;
  --coral-soft: #f4e1db;
  --gold: #aa7a2f;
  --gold-soft: #f5ecd9;
  --serif: "Latin Modern Roman", "Noto Serif CJK SC", "Source Han Serif SC", Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans CJK SC", sans-serif;
  --measure: 760px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
body::selection { color: var(--ink); background: #ecdcae; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible, a:focus-visible, input:focus-visible, summary:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 3px;
}

/* A quiet, document-like header. */
.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  min-height: 62px;
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 12px max(20px, calc((100% - 1160px) / 2));
  border-bottom: 1px solid var(--line);
  background: rgba(247,245,239,.96);
  backdrop-filter: blur(12px);
}
.wordmark { display: inline-flex; align-items: center; gap: 8px; color: var(--ink); font-size: 13px; font-weight: 800; letter-spacing: .2em; white-space: nowrap; }
.wordmark-mark { color: var(--coral); font-size: 21px; letter-spacing: 0; transform: translateY(-1px); }
.wordmark small { padding-left: 10px; border-left: 1px solid var(--line); color: var(--muted); font-size: 9px; font-weight: 600; letter-spacing: .15em; }
.topbar-note { margin-inline: auto; color: var(--muted); font-family: var(--serif); font-size: 12px; }
.topbar-actions { display: flex; align-items: center; gap: 8px; }
.topbar-button {
  min-height: 32px;
  padding: 0 10px;
  border: 1px solid transparent;
  border-radius: 5px;
  color: var(--muted);
  background: transparent;
  font-size: 11px;
}
.topbar-button:hover, .topbar-button[aria-pressed="true"] { color: var(--ink); border-color: var(--line); background: var(--white); }
.button-count { color: var(--teal); font-variant-numeric: tabular-nums; }

.reader-page { width: min(1160px, calc(100% - 40px)); margin: 0 auto; padding: 54px 0 80px; }
.reader-intro { display: flex; justify-content: space-between; gap: 40px; padding-bottom: 34px; border-bottom: 1px solid var(--line); }
.kicker { margin: 0 0 10px; color: var(--teal); font-size: 9px; font-weight: 800; letter-spacing: .18em; line-height: 1.25; text-transform: uppercase; }
h1, h2, h3, h4, p { margin-top: 0; }
h1 { margin-bottom: 11px; font-family: var(--serif); font-size: clamp(35px, 5vw, 54px); font-weight: 500; letter-spacing: -.04em; line-height: 1.05; }
.intro-copy { max-width: 560px; margin: 0; color: var(--ink-soft); font-family: var(--serif); font-size: 15px; line-height: 1.8; }
.document-meta { display: flex; gap: 20px; align-items: flex-end; margin: 0; padding-bottom: 3px; }
.document-meta div { min-width: 45px; }
.document-meta dt { color: var(--muted-light); font-size: 10px; }
.document-meta dd { margin: 2px 0 0; color: var(--ink); font-family: var(--serif); font-size: 25px; line-height: 1; }

.reading-tools { display: flex; align-items: center; flex-wrap: wrap; gap: 15px; padding: 18px 0 20px; border-bottom: 1px solid var(--line); }
.search-box, .dialog-search { display: flex; align-items: center; gap: 9px; min-height: 37px; padding: 0 10px; border: 1px solid var(--line); border-radius: 5px; background: var(--white); color: var(--muted); }
.search-box { flex: 1 1 310px; max-width: 475px; }
.search-box:focus-within, .dialog-search:focus-within { border-color: var(--teal); box-shadow: 0 0 0 3px rgba(44,113,107,.10); }
.search-symbol { color: var(--muted-light); font-size: 19px; line-height: 1; }
.search-box input, .dialog-search input { min-width: 0; flex: 1; border: 0; outline: 0; color: var(--ink); background: transparent; font-size: 12px; }
.search-box input::placeholder, .dialog-search input::placeholder { color: var(--muted-light); }
kbd { padding: 1px 5px; border: 1px solid var(--line); border-radius: 3px; color: var(--muted-light); background: var(--paper); font-family: var(--sans); font-size: 10px; }
.reading-legend { display: flex; flex-wrap: wrap; gap: 12px; color: var(--muted); font-size: 11px; }
.reading-legend span { display: inline-flex; align-items: center; gap: 5px; }
.legend-sample { font-family: var(--serif); font-size: 12px; }
.legend-term { color: var(--teal); text-decoration: underline; text-decoration-color: #8dbbb1; text-decoration-thickness: 2px; text-underline-offset: 3px; }
.legend-error { color: var(--coral); text-decoration: underline dotted var(--coral); text-underline-offset: 3px; }
.search-count { margin-left: auto; color: var(--muted); font-size: 10px; font-variant-numeric: tabular-nums; white-space: nowrap; }

.reader-columns { display: grid; grid-template-columns: minmax(0, var(--measure)) minmax(250px, 300px); gap: 58px; align-items: start; }
.lecture-document { min-width: 0; padding-top: 20px; }
.doc-section { scroll-margin-top: 86px; padding: 23px 0 31px; border-bottom: 1px solid var(--line); }
.doc-section:last-child { border-bottom: 0; }
.section-heading { display: grid; grid-template-columns: 30px minmax(0, 1fr); gap: 13px; align-items: start; margin-bottom: 17px; }
.section-number { color: var(--coral); font-size: 11px; font-variant-numeric: tabular-nums; padding-top: 5px; }
.section-title-fr { margin: 0 0 3px; color: var(--ink); font-family: var(--serif); font-size: 21px; font-weight: 500; line-height: 1.38; }
.section-title-zh { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.5; }
.section-note { margin: 0 0 18px 43px; border-left: 2px solid var(--gold); }
.section-note summary { padding-left: 10px; color: var(--gold); font-size: 10px; cursor: pointer; list-style: none; }
.section-note summary::-webkit-details-marker { display: none; }
.section-note summary::before { content: "+"; display: inline-block; width: 16px; color: var(--gold); font-size: 14px; }
.section-note[open] summary::before { content: "−"; }
.section-note p { max-width: 650px; margin: 8px 0 0; padding: 0 10px; color: var(--ink-soft); font-family: var(--serif); font-size: 13px; line-height: 1.7; }
.paragraph-block + .paragraph-block { margin-top: 16px; }
.paragraph-meta { display: flex; justify-content: space-between; margin: 0 0 3px 43px; color: var(--muted-light); font-size: 9px; letter-spacing: .07em; text-transform: uppercase; }
.sentence-line { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 9px; padding: 10px 7px 11px; margin: 0 -7px; border-radius: 4px; scroll-margin-top: 83px; }
.sentence-line:hover { background: rgba(255,254,250,.82); }
.sentence-line.is-selected { background: var(--teal-soft); box-shadow: inset 2px 0 0 var(--teal); }
.sentence-line.pulse { animation: sentence-pulse 1.05s ease; }
@keyframes sentence-pulse { 0%, 100% { background: transparent; } 35% { background: var(--gold-soft); } }
.sentence-gutter { padding-top: 5px; color: var(--muted-light); font-size: 9px; font-variant-numeric: tabular-nums; line-height: 1.25; text-align: right; }
.sentence-gutter .page-number { display: block; margin-top: 4px; color: #b9bfba; font-size: 8px; }
.sentence-copy { min-width: 0; }
.sentence-fr, .sentence-zh { margin: 0; overflow-wrap: anywhere; white-space: pre-wrap; }
.sentence-fr { color: var(--ink); font-family: var(--serif); font-size: 16px; line-height: 1.75; }
.sentence-zh { margin-top: 4px; color: var(--ink-soft); font-size: 13px; line-height: 1.7; }
body.hide-translations .sentence-zh { display: none; }
.annotation-mark { padding: 0 1px; border: 0; border-radius: 2px; background: transparent; font: inherit; cursor: pointer; }
.annotation-term { color: var(--teal); text-decoration: underline; text-decoration-color: #8dbbb1; text-decoration-thickness: 2px; text-underline-offset: 3px; }
.annotation-term:hover, .annotation-term:focus-visible { background: var(--teal-soft); }
.annotation-error { color: var(--coral); text-decoration: underline dotted var(--coral); text-underline-offset: 3px; }
.annotation-error:hover, .annotation-error:focus-visible { background: var(--coral-soft); }

/* The annotation rail replaces the old multi-page navigation. */
.annotation-panel { position: sticky; top: 91px; min-height: 330px; padding: 18px 18px 20px; border-left: 1px solid var(--line); background: rgba(247,245,239,.55); }
.annotation-head { display: flex; align-items: center; justify-content: space-between; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.annotation-title { color: var(--ink); font-family: var(--serif); font-size: 17px; }
.close-button { width: 27px; height: 27px; padding: 0; border: 1px solid var(--line); border-radius: 50%; color: var(--muted); background: var(--white); font-size: 19px; line-height: 1; }
.close-button:hover { color: var(--ink); border-color: var(--ink-soft); }
.annotation-empty { padding: 47px 7px 20px; color: var(--muted); text-align: center; }
.annotation-empty-mark { display: block; margin-bottom: 13px; color: var(--teal); font-family: var(--serif); font-size: 30px; }
.annotation-empty p { margin: 0 auto 7px; max-width: 180px; font-family: var(--serif); font-size: 14px; line-height: 1.65; }
.annotation-empty small { color: var(--muted-light); font-size: 10px; }
.annotation-content { padding-top: 17px; }
.annotation-content[hidden], .annotation-empty[hidden] { display: none; }
.annotation-kind { margin: 0 0 8px; color: var(--teal); font-size: 9px; font-weight: 800; letter-spacing: .15em; text-transform: uppercase; }
.annotation-content.error-content .annotation-kind { color: var(--coral); }
.annotation-heading { margin: 0; color: var(--ink); font-family: var(--serif); font-size: 25px; font-weight: 500; line-height: 1.25; overflow-wrap: anywhere; }
.annotation-translation { margin: 5px 0 17px; color: var(--coral); font-size: 14px; font-weight: 700; }
.annotation-section { margin-top: 17px; padding-top: 13px; border-top: 1px solid var(--line); }
.annotation-section h3 { margin: 0 0 7px; color: var(--muted-light); font-size: 9px; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
.annotation-section p { margin: 0; color: var(--ink-soft); font-family: var(--serif); font-size: 13px; line-height: 1.75; }
.annotation-context { padding: 10px 11px; background: var(--white); }
.annotation-compare { display: grid; gap: 7px; }
.annotation-compare > div { padding: 9px 10px; border-radius: 3px; font-family: var(--serif); font-size: 14px; line-height: 1.55; overflow-wrap: anywhere; }
.annotation-compare .original { color: var(--ink-soft); background: var(--paper-deep); }
.annotation-compare .suggestion { color: var(--coral); background: var(--coral-soft); }
.annotation-label { display: block; margin-bottom: 3px; color: var(--muted-light); font-family: var(--sans); font-size: 9px; }
.annotation-source-list { display: grid; gap: 7px; }
.annotation-source-list a { color: var(--teal); font-size: 11px; line-height: 1.45; }
.annotation-source-list a:hover { text-decoration: underline; }
.annotation-source-list small { color: var(--muted); font-size: 10px; }
.annotation-action { margin-top: 15px; padding: 0; border: 0; color: var(--teal); background: transparent; font-size: 11px; }
.annotation-action:hover { text-decoration: underline; }
.annotation-backdrop { display: none; }

/* A compact term index, not a second application view. */
.terms-dialog { width: min(620px, calc(100% - 28px)); max-height: min(720px, calc(100vh - 36px)); padding: 24px; border: 1px solid var(--line); border-radius: 7px; color: var(--ink); background: var(--paper); box-shadow: 0 20px 60px rgba(35,45,42,.2); }
.terms-dialog::backdrop { background: rgba(27,38,36,.35); }
.dialog-head { display: flex; align-items: start; justify-content: space-between; gap: 20px; margin-bottom: 17px; }
.dialog-head h2 { margin: 0; font-family: var(--serif); font-size: 29px; font-weight: 500; }
.dialog-search { margin-bottom: 15px; }
.term-index-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 16px; max-height: 495px; overflow: auto; }
.term-index-item { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: baseline; gap: 8px; padding: 9px 0; border-bottom: 1px solid var(--line-soft); text-align: left; }
.term-index-item:hover .term-index-fr { color: var(--teal); }
.term-index-fr { color: var(--ink); font-family: var(--serif); font-size: 14px; }
.term-index-zh { color: var(--coral); font-size: 11px; }
.term-index-category { grid-column: 1 / -1; color: var(--muted-light); font-size: 9px; }
.term-index-empty { grid-column: 1 / -1; padding: 30px 0; color: var(--muted); text-align: center; font-family: var(--serif); }

.toast { position: fixed; left: 50%; bottom: 22px; z-index: 60; max-width: calc(100% - 30px); padding: 8px 12px; border: 1px solid var(--line); border-radius: 4px; color: var(--ink); background: var(--white); box-shadow: 0 8px 24px rgba(36,44,43,.13); font-size: 11px; opacity: 0; pointer-events: none; transform: translate(-50%, 10px); transition: opacity .18s, transform .18s; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 900px) {
  .reader-columns { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .annotation-panel { position: fixed; left: 14px; right: 14px; bottom: 14px; z-index: 50; max-height: min(75vh, 610px); min-height: 0; overflow: auto; border: 1px solid var(--line); border-radius: 7px; background: var(--paper); box-shadow: 0 18px 55px rgba(28,39,37,.24); opacity: 0; pointer-events: none; transform: translateY(calc(100% + 24px)); transition: opacity .2s, transform .2s; }
  .annotation-panel.is-open { opacity: 1; pointer-events: auto; transform: translateY(0); }
  .annotation-backdrop:not([hidden]) { display: block; position: fixed; inset: 0; z-index: 40; background: rgba(29,38,36,.22); }
  .annotation-empty { padding: 22px 7px 16px; }
}

@media (max-width: 640px) {
  .topbar { gap: 12px; padding-inline: 14px; }
  .wordmark small, .topbar-note { display: none; }
  .topbar-actions { margin-left: auto; }
  .topbar-button { padding-inline: 7px; }
  .reader-page { width: min(100% - 28px, 760px); padding-top: 31px; }
  .reader-intro { display: block; padding-bottom: 25px; }
  h1 { font-size: 39px; }
  .intro-copy { font-size: 14px; }
  .document-meta { gap: 18px; margin-top: 23px; }
  .reading-tools { align-items: stretch; gap: 10px; padding-top: 13px; }
  .search-box { flex-basis: 100%; max-width: none; }
  .reading-legend { flex: 1; align-self: center; gap: 9px; }
  .search-count { align-self: center; }
  .lecture-document { padding-top: 9px; }
  .doc-section { padding-top: 19px; }
  .section-title-fr { font-size: 19px; }
  .section-note { margin-left: 43px; }
  .paragraph-meta { margin-left: 43px; }
  .sentence-line { grid-template-columns: 27px minmax(0, 1fr); gap: 7px; padding-block: 9px; }
  .sentence-fr { font-size: 15px; line-height: 1.7; }
  .sentence-zh { font-size: 13px; line-height: 1.65; }
  .term-index-list { grid-template-columns: 1fr; }
  .terms-dialog { padding: 19px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .001ms !important; }
}