:root {
  --ink: #17343b;
  --text: #27343a;
  --teal: #0f6b6d;
  --teal-light: #e2f0ee;
  --terracotta: #c95f45;
  --mustard: #e1a72f;
  --blue: #315c7d;
  --paper: #fffdf8;
  --cream: #f3eee3;
  --line: #cbd2ce;
  --muted: #657276;
  --white: #ffffff;
  --bleed-w: 154mm;
  --bleed-h: 216mm;
  --trim-w: 148mm;
  --trim-h: 210mm;
  --zoom: 0.78;
  font-family: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  color: var(--text);
  background: #dfe4e2;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background: #dfe4e2;
}

button,
select {
  font: inherit;
}

.screen-toolbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 58px;
  padding: 10px max(16px, calc((100vw - 1260px) / 2));
  color: var(--paper);
  background: var(--ink);
  border-bottom: 4px solid var(--mustard);
  max-height: 360px;
  overflow: hidden;
  transition: max-height 180ms ease, min-height 180ms ease, padding 180ms ease, border-width 180ms ease, opacity 160ms ease;
}

.toolbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  min-width: 210px;
}

.toolbar-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  color: var(--ink);
  background: var(--mustard);
  border-radius: 50%;
  font-weight: 900;
}

.toolbar-brand strong,
.toolbar-brand small {
  display: block;
}

.toolbar-brand strong {
  font-size: 14px;
}

.toolbar-brand small {
  margin-top: 2px;
  color: #dbe4e1;
  font-size: 11px;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.toolbar-label {
  font-size: 12px;
  color: #dbe4e1;
}

.toolbar-button,
.toolbar-select {
  min-height: 34px;
  padding: 6px 10px;
  color: var(--paper);
  background: transparent;
  border: 1px solid #729095;
  border-radius: 6px;
  cursor: pointer;
}

a.toolbar-button {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.toolbar-button:hover,
.toolbar-button:focus-visible,
.toolbar-select:hover,
.toolbar-select:focus-visible {
  border-color: var(--mustard);
  outline: 2px solid transparent;
}

.toolbar-button.primary {
  color: var(--ink);
  background: var(--mustard);
  border-color: var(--mustard);
  font-weight: 800;
}

.toolbar-hide-button {
  white-space: nowrap;
}

.toolbar-reveal {
  position: fixed;
  top: max(12px, env(safe-area-inset-top));
  right: max(12px, env(safe-area-inset-right));
  z-index: 120;
  min-height: 42px;
  padding: 9px 14px;
  color: var(--paper);
  background: var(--ink);
  border: 1px solid #729095;
  border-radius: 999px;
  box-shadow: 0 8px 20px rgb(23 52 59 / 24%);
  cursor: pointer;
  font-weight: 800;
}

.toolbar-reveal:hover,
.toolbar-reveal:focus-visible {
  border-color: var(--mustard);
  outline: 2px solid transparent;
}

.toolbar-reveal[hidden] {
  display: none;
}

body.toolbar-hidden .screen-toolbar,
body.toolbar-hidden .gallery-toolbar {
  min-height: 0;
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  gap: 0;
  overflow: hidden;
  pointer-events: none;
  visibility: hidden;
  opacity: 0;
  border-bottom-width: 0;
}

.toolbar-select {
  max-width: 190px;
  color-scheme: dark;
}

.book-preview {
  display: grid;
  grid-template-columns: repeat(2, max-content);
  align-items: start;
  justify-content: center;
  gap: 22px;
  padding: 34px 22px 90px;
}

.single-page .book-preview {
  grid-template-columns: max-content;
}

.sheet {
  position: relative;
  width: var(--bleed-w);
  height: var(--bleed-h);
  overflow: hidden;
  color: var(--text);
  background: var(--paper);
  box-shadow: 0 16px 40px rgb(23 52 59 / 20%);
  zoom: var(--zoom);
  break-after: page;
  page-break-after: always;
}

.sheet:last-child {
  break-after: auto;
  page-break-after: auto;
}

.trim-page {
  position: absolute;
  inset: 3mm;
  display: flex;
  flex-direction: column;
  width: var(--trim-w);
  height: var(--trim-h);
  padding-top: 12mm;
  padding-bottom: 14mm;
  overflow: hidden;
  background: var(--paper);
}

.sheet[data-side="recto"] .trim-page {
  padding-left: 15mm;
  padding-right: 12mm;
}

.sheet[data-side="verso"] .trim-page {
  padding-left: 12mm;
  padding-right: 15mm;
}

.sheet.full-bleed,
.sheet.full-bleed .trim-page {
  background: var(--teal);
}

.sheet.full-bleed .trim-page {
  inset: 0;
  width: 100%;
  height: 100%;
  padding: 0;
}

.page-main {
  position: relative;
  z-index: 1;
  display: flex;
  flex: 1 1 auto;
  min-height: 0;
  flex-direction: column;
}

.folio {
  position: absolute;
  z-index: 4;
  bottom: 6.5mm;
  right: 12mm;
  display: flex;
  align-items: center;
  gap: 2.5mm;
  color: var(--muted);
  font-size: 8.5pt;
  font-weight: 700;
}

.folio::before {
  content: "";
  width: 8mm;
  height: 0.45mm;
  background: var(--mustard);
}

.page-kicker,
.eyebrow {
  margin: 0 0 2.5mm;
  color: var(--teal);
  font-size: 8.5pt;
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.section-title {
  margin: 0;
  color: var(--ink);
  font-size: 18pt;
  line-height: 1.25;
  font-weight: 850;
}

.section-deck {
  max-width: 112mm;
  margin: 2mm 0 5mm;
  color: var(--text);
  font-size: 9.5pt;
  line-height: 1.6;
}

.rule {
  width: 22mm;
  height: 1.2mm;
  margin: 3mm 0 5mm;
  background: var(--terracotta);
}

.cover-art {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  opacity: 0.26;
  filter: saturate(0.78) contrast(1.08);
}

.cover-wash {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgb(15 107 109 / 96%) 0 55%, rgb(15 107 109 / 78%) 75%, rgb(15 107 109 / 52%) 100%);
}

.cover-content {
  position: relative;
  z-index: 2;
  display: flex;
  height: 100%;
  flex-direction: column;
  padding: 19mm 16mm 14mm;
  color: var(--paper);
}

.series-label {
  align-self: flex-start;
  padding: 2mm 3.5mm;
  color: var(--ink);
  background: var(--mustard);
  border-radius: 999px;
  font-size: 8pt;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.cover-title {
  max-width: 118mm;
  margin: 13mm 0 4mm;
  font-family: "Noto Serif TC", "Songti TC", "PMingLiU", serif;
  font-size: 32pt;
  line-height: 1.16;
  font-weight: 900;
  letter-spacing: 0.01em;
}

.cover-subtitle {
  max-width: 103mm;
  margin: 0;
  color: #f7f1e5;
  font-size: 13pt;
  line-height: 1.6;
  font-weight: 650;
}

.cover-stats {
  display: flex;
  gap: 4mm;
  margin-top: 9mm;
}

.cover-stat {
  padding: 3mm 4mm;
  border: 0.35mm solid rgb(255 253 248 / 66%);
  border-radius: 3mm;
}

.cover-stat strong {
  display: block;
  color: var(--mustard);
  font-size: 16pt;
}

.cover-stat span {
  display: block;
  margin-top: 0.5mm;
  font-size: 8pt;
}

.cover-footer {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 8mm;
  margin-top: auto;
}

.cover-footer p {
  max-width: 80mm;
  margin: 0;
  font-size: 9.5pt;
  line-height: 1.55;
}

.cover-badge {
  display: grid;
  place-items: center;
  width: 24mm;
  height: 24mm;
  color: var(--ink);
  background: var(--paper);
  border-radius: 50%;
  font-size: 11pt;
  font-weight: 900;
}

.inside-cover {
  display: grid;
  height: 100%;
  place-items: center;
  color: var(--paper);
  background: var(--teal);
  text-align: center;
}

.inside-cover blockquote {
  max-width: 96mm;
  margin: 0;
  font-family: "Noto Serif TC", "Songti TC", serif;
  font-size: 20pt;
  line-height: 1.55;
  font-weight: 750;
}

.inside-cover small {
  display: block;
  margin-top: 7mm;
  color: #dbe9e6;
  font-family: "Noto Sans TC", sans-serif;
  font-size: 9pt;
  letter-spacing: 0.08em;
}

.title-page {
  justify-content: center;
}

.title-page .book-title {
  max-width: 112mm;
  margin: 0;
  color: var(--ink);
  font-family: "Noto Serif TC", "Songti TC", serif;
  font-size: 27pt;
  line-height: 1.28;
  font-weight: 900;
}

.title-page .book-subtitle {
  max-width: 105mm;
  margin: 5mm 0 0;
  color: var(--teal);
  font-size: 12.5pt;
  line-height: 1.65;
  font-weight: 650;
}

.title-meta {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 3mm;
  margin-top: 18mm;
}

.title-meta div {
  padding: 4mm;
  background: var(--cream);
  border-top: 1mm solid var(--mustard);
  border-radius: 0 0 3mm 3mm;
}

.title-meta strong,
.title-meta span {
  display: block;
}

.title-meta strong {
  color: var(--ink);
  font-size: 12pt;
}

.title-meta span {
  margin-top: 1.5mm;
  font-size: 8.5pt;
}

.copyright-box {
  margin-top: auto;
  padding: 5mm;
  background: var(--cream);
  border: 0.35mm solid var(--line);
  border-radius: 3mm;
  font-size: 8.5pt;
  line-height: 1.75;
}

.copyright-box p {
  margin: 0 0 2mm;
}

.copyright-box p:last-child {
  margin-bottom: 0;
}

.toc-list {
  display: grid;
  gap: 3mm;
  margin-top: 6mm;
}

.toc-item {
  display: grid;
  grid-template-columns: 11mm 1fr auto;
  align-items: baseline;
  gap: 3mm;
  padding: 3mm 0;
  border-bottom: 0.35mm solid var(--line);
}

.toc-number {
  color: var(--terracotta);
  font-size: 11pt;
  font-weight: 900;
}

.toc-copy strong {
  display: block;
  color: var(--ink);
  font-size: 11pt;
  line-height: 1.35;
}

.toc-copy small {
  display: block;
  margin-top: 1mm;
  color: var(--muted);
  font-size: 7.8pt;
  line-height: 1.4;
}

.toc-page {
  color: var(--teal);
  font-size: 9.5pt;
  font-weight: 800;
}

.panel-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4mm;
  margin-top: 5mm;
}

.panel {
  padding: 4.5mm;
  background: var(--cream);
  border-top: 1mm solid var(--teal);
  border-radius: 0 0 3mm 3mm;
}

.panel.accent {
  border-top-color: var(--terracotta);
}

.panel.mustard {
  border-top-color: var(--mustard);
}

.panel.blue {
  border-top-color: var(--blue);
}

.panel h3 {
  margin: 0 0 2mm;
  color: var(--ink);
  font-size: 11pt;
  line-height: 1.35;
}

.panel p,
.panel li {
  margin: 0;
  font-size: 8.8pt;
  line-height: 1.62;
}

.panel ul,
.panel ol {
  margin: 2mm 0 0;
  padding-left: 4.8mm;
}

.icon-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 3mm 5mm;
  margin-top: 6mm;
}

.icon-row {
  display: grid;
  grid-template-columns: 9mm 1fr;
  gap: 3mm;
  align-items: start;
  padding: 3mm 0;
  border-bottom: 0.35mm solid var(--line);
}

.icon-chip {
  display: grid;
  width: 8mm;
  height: 8mm;
  place-items: center;
  color: var(--paper);
  background: var(--teal);
  border-radius: 50%;
  font-size: 7.5pt;
  font-weight: 900;
}

.icon-row strong,
.icon-row span {
  display: block;
}

.icon-row strong {
  color: var(--ink);
  font-size: 9.5pt;
}

.icon-row span {
  margin-top: 1mm;
  font-size: 8pt;
  line-height: 1.45;
}

.sample-card {
  margin-top: 6mm;
  padding: 5mm;
  background: var(--paper);
  border: 0.45mm solid var(--line);
  border-top: 1.5mm solid var(--teal);
  border-radius: 3mm;
}

.sample-labels {
  display: flex;
  gap: 2mm;
  margin-bottom: 3mm;
}

.chip {
  display: inline-flex;
  align-items: center;
  min-height: 5mm;
  padding: 1mm 2.3mm;
  color: var(--ink);
  background: var(--teal-light);
  border-radius: 999px;
  font-size: 7.5pt;
  line-height: 1;
  font-weight: 800;
}

.chip.register {
  background: #f5dfd8;
}

.chip.region {
  background: #e3e9f1;
}

.sample-card .es {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Inter", "Helvetica Neue", Arial, sans-serif;
  font-size: 17pt;
  line-height: 1.3;
  font-weight: 800;
}

.sample-card .zh {
  margin: 2mm 0 0;
  font-size: 10.5pt;
  line-height: 1.55;
  font-weight: 650;
}

.sample-card .note {
  margin: 3mm 0 0;
  padding-top: 3mm;
  border-top: 0.35mm solid var(--line);
  font-size: 8.5pt;
  line-height: 1.6;
}

.register-table {
  display: grid;
  grid-template-columns: 30mm 1fr;
  margin-top: 6mm;
  border: 0.35mm solid var(--line);
  border-radius: 3mm;
  overflow: hidden;
}

.register-table > div {
  padding: 3.5mm;
  border-bottom: 0.35mm solid var(--line);
}

.register-table > div:nth-last-child(-n + 2) {
  border-bottom: 0;
}

.register-table > div:nth-child(odd) {
  color: var(--ink);
  background: var(--cream);
  font-size: 9pt;
  font-weight: 800;
}

.register-table > div:nth-child(even) {
  font-size: 8.5pt;
  line-height: 1.55;
}

.region-callout {
  margin-top: 5mm;
  padding: 4.5mm;
  background: var(--teal-light);
  border-left: 1.2mm solid var(--teal);
  border-radius: 0 3mm 3mm 0;
  font-size: 8.7pt;
  line-height: 1.65;
}

.route {
  display: grid;
  gap: 0;
  margin-top: 8mm;
}

.route-step {
  display: grid;
  grid-template-columns: 10mm 1fr;
  gap: 4mm;
  min-height: 24mm;
}

.route-dot {
  position: relative;
  display: grid;
  width: 8mm;
  height: 8mm;
  place-items: center;
  color: var(--paper);
  background: var(--teal);
  border-radius: 50%;
  font-size: 7.5pt;
  font-weight: 900;
}

.route-step:not(:last-child) .route-dot::after {
  content: "";
  position: absolute;
  top: 8mm;
  left: 3.6mm;
  width: 0.7mm;
  height: 16mm;
  background: var(--mustard);
}

.route-copy strong {
  display: block;
  color: var(--ink);
  font-size: 10.5pt;
}

.route-copy span {
  display: block;
  margin-top: 1mm;
  font-size: 8.3pt;
  line-height: 1.5;
}

.chapter-opener .page-main {
  gap: 0;
}

.chapter-heading {
  display: grid;
  grid-template-columns: 14mm 1fr;
  gap: 4mm;
  align-items: start;
  margin-bottom: 4mm;
}

.chapter-number {
  display: grid;
  width: 13mm;
  height: 13mm;
  place-items: center;
  color: var(--paper);
  background: var(--terracotta);
  border-radius: 50%;
  font-size: 13pt;
  font-weight: 900;
}

.chapter-title {
  margin: 0;
  color: var(--ink);
  font-size: 23pt;
  line-height: 1.2;
  font-weight: 900;
}

.chapter-intro {
  margin: 2mm 0 0;
  font-size: 9.5pt;
  line-height: 1.6;
}

.chapter-intro-paragraph {
  margin: 0;
}

.chapter-intro-paragraph + .chapter-intro-paragraph {
  margin-top: 1mm;
}

.hero-frame {
  position: relative;
  min-height: 76mm;
  margin: 0;
  overflow: hidden;
  background: var(--cream);
  border-radius: 4mm 4mm 0 0;
}

.hero-frame img {
  display: block;
  width: 100%;
  height: 76mm;
  object-fit: cover;
}

.hero-caption {
  position: absolute;
  right: 3mm;
  bottom: 3mm;
  padding: 1.5mm 2.5mm;
  color: var(--paper);
  background: var(--ink);
  border-radius: 999px;
  font-size: 7pt;
  font-weight: 750;
}

.placeholder-art {
  display: grid;
  min-height: 76mm;
  place-items: center;
  padding: 8mm;
  color: var(--teal);
  background:
    linear-gradient(135deg, transparent 0 48%, #dbe8e5 48% 52%, transparent 52%),
    var(--cream);
  border: 0.5mm dashed var(--teal);
  border-radius: 4mm;
  text-align: center;
}

.placeholder-art strong,
.placeholder-art span {
  display: block;
}

.placeholder-art strong {
  font-size: 13pt;
}

.placeholder-art span {
  max-width: 78mm;
  margin-top: 2mm;
  color: var(--text);
  font-size: 8.5pt;
  line-height: 1.5;
}

.goals-box {
  padding: 4mm;
  background: var(--teal-light);
  border-left: 1.2mm solid var(--teal);
  border-radius: 0 3mm 3mm 0;
}

.goals-box h2 {
  margin: 0 0 2.5mm;
  color: var(--ink);
  font-size: 11pt;
}

.goals-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 3mm;
  margin: 0;
  padding: 0;
  list-style: none;
}

.goals-list li {
  position: relative;
  padding-left: 5mm;
  font-size: 8.4pt;
  line-height: 1.5;
}

.goals-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--teal);
  font-weight: 900;
}

.scene-usage-box {
  padding: 3.2mm;
  background: var(--teal-light);
  border-left: 1.2mm solid var(--teal);
  border-radius: 0 0 3mm 3mm;
}

.scene-usage-box h2 {
  margin: 0 0 1.8mm;
  color: var(--ink);
  font-size: 10.5pt;
}

.scene-usage-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.2mm;
}

.scene-usage-item {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 2mm;
  align-items: start;
  min-width: 0;
  padding: 1.8mm 2.3mm;
  background: rgba(255, 255, 255, 0.72);
  border-radius: 2.2mm;
}

.scene-usage-phrase {
  margin: 0;
  color: var(--teal);
  font-family: "Aptos", "Inter", "Helvetica Neue", Arial, sans-serif;
  font-size: 8pt;
  line-height: 1.28;
  font-weight: 800;
}

.scene-usage-when {
  margin: 0;
  color: var(--text);
  font-size: 6.8pt;
  line-height: 1.4;
}

.scene-usage-when strong {
  display: block;
  margin-bottom: 0.5mm;
  color: var(--ink);
  font-size: 6.4pt;
  letter-spacing: 0.08em;
}

.survival-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 3.5mm;
  margin-top: 5mm;
}

.survival-card {
  display: grid;
  grid-template-columns: 8mm 1fr;
  gap: 3mm;
  min-height: 31mm;
  padding: 3.5mm;
  background: var(--teal-light);
  border: 0.4mm solid #b8d5d0;
  border-radius: 3mm;
}

.survival-index {
  display: grid;
  width: 7mm;
  height: 7mm;
  place-items: center;
  color: var(--paper);
  background: var(--teal);
  border-radius: 50%;
  font-size: 7.5pt;
  font-weight: 900;
}

.survival-card .es {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Inter", Arial, sans-serif;
  font-size: 12.5pt;
  line-height: 1.32;
  font-weight: 800;
}

.survival-card .zh {
  margin: 1.5mm 0 0;
  font-size: 8.5pt;
  line-height: 1.45;
}

.survival-page .survival-grid {
  grid-template-rows: repeat(4, minmax(0, 1fr));
  flex: 1;
  min-height: 0;
  gap: 2.5mm;
  margin-top: 2mm;
}

.survival-page .survival-card {
  min-height: 0;
  padding: 2.7mm;
}

.survival-page .survival-card .es {
  font-size: 10.8pt;
  line-height: 1.26;
}

.survival-page .survival-card .zh {
  margin-top: 1mm;
  font-size: 7.7pt;
  line-height: 1.35;
}

.sentence-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-template-rows: repeat(2, minmax(0, 1fr));
  gap: 3.5mm;
  flex: 1;
  min-height: 0;
  margin-top: 4mm;
}

.sentence-page .sentence-grid {
  grid-template-rows: repeat(2, minmax(max-content, 1fr));
  align-content: stretch;
  gap: 2.5mm;
  margin-top: 2mm;
}

.survival-page .section-deck,
.sentence-page .section-deck {
  margin-bottom: 2mm;
}

.survival-page .rule,
.sentence-page .rule {
  margin: 1mm 0 2mm;
}

.sentence-card {
  position: relative;
  display: flex;
  min-height: 0;
  flex-direction: column;
  padding: 3.6mm;
  background: var(--paper);
  border: 0.4mm solid var(--line);
  border-top: 1.2mm solid var(--teal);
  border-radius: 3mm;
  break-inside: avoid;
  page-break-inside: avoid;
}

.sentence-card.staff {
  border-top-color: var(--blue);
}

.sentence-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.4mm;
  align-items: center;
  margin-bottom: 2.5mm;
}

.purpose {
  margin-right: auto;
  color: var(--ink);
  font-size: 7.6pt;
  line-height: 1.2;
  font-weight: 850;
}

.speaker-badge {
  padding: 1mm 2mm;
  color: var(--paper);
  background: var(--teal);
  border-radius: 999px;
  font-size: 6.7pt;
  line-height: 1;
  font-weight: 800;
}

.sentence-card.staff .speaker-badge {
  background: var(--blue);
}

.register-badge,
.region-badge {
  padding: 1mm 1.8mm;
  color: var(--ink);
  background: var(--cream);
  border-radius: 999px;
  font-size: 6.6pt;
  line-height: 1;
  font-weight: 750;
}

.region-badge {
  background: #e3e9f1;
}

.sentence-es {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Inter", "Helvetica Neue", Arial, sans-serif;
  font-size: 13.5pt;
  line-height: 1.29;
  font-weight: 800;
  overflow-wrap: anywhere;
}

.sentence-zh {
  margin: 1.7mm 0 0;
  font-size: 9pt;
  line-height: 1.48;
  font-weight: 650;
}

.sentence-usage {
  margin: 2mm 0 0;
  color: #4b585c;
  font-size: 7.5pt;
  line-height: 1.52;
}

.replacement-box {
  margin-top: auto;
  padding-top: 2mm;
  border-top: 0.35mm solid var(--line);
  font-size: 7.2pt;
  line-height: 1.45;
}

.sentence-page .replacement-box {
  margin-top: 2mm;
}

.replacement-box strong {
  color: var(--teal);
}

.region-note {
  margin: 1.5mm 0 0;
  color: var(--blue);
  font-size: 6.9pt;
  line-height: 1.4;
}

.scene-dialogue-page .page-main {
  gap: 0;
}

.scene-dialogue-intro {
  display: grid;
  grid-template-columns: 32mm minmax(0, 1fr);
  gap: 4mm;
  align-items: center;
  margin-bottom: 2mm;
}

.scene-dialogue-intro img {
  display: block;
  width: 32mm;
  height: 24mm;
  object-fit: cover;
  border-radius: 3mm;
}

.scene-dialogue-intro .page-kicker {
  margin-bottom: 1mm;
  font-size: 6.8pt;
}

.scene-dialogue-intro h1 {
  margin: 0;
  color: var(--ink);
  font-size: 16.5pt;
  line-height: 1.22;
}

.scene-dialogue-intro div > p:last-child {
  margin: 1.3mm 0 0;
  color: var(--muted);
  font-size: 6.9pt;
  line-height: 1.4;
}

.scene-dialogue-guide {
  display: flex;
  justify-content: space-between;
  gap: 3mm;
  padding: 1.2mm 2.3mm;
  color: var(--muted);
  background: var(--cream);
  border-radius: 999px;
  font-size: 6.2pt;
  font-weight: 800;
}

.scene-dialogue-guide span:last-child {
  color: var(--teal);
}

.scene-chat {
  display: flex;
  flex: 1 1 auto;
  min-height: 0;
  flex-direction: column;
  gap: 1.15mm;
  margin-top: 1.8mm;
}

.scene-chat-row {
  display: flex;
  width: 100%;
  break-inside: avoid;
  page-break-inside: avoid;
}

.scene-chat-row.right {
  justify-content: flex-end;
}

.scene-chat-row.left {
  justify-content: flex-start;
}

.scene-bubble {
  max-width: 88%;
  padding: 1.7mm 2.6mm 1.8mm;
  background: #e8eef3;
  border-left: 1.1mm solid var(--blue);
  border-radius: 1.5mm 4mm 4mm 4mm;
}

.scene-chat-row.right .scene-bubble {
  border-right: 1.1mm solid var(--teal);
  border-left: 0;
  border-radius: 4mm 1.5mm 4mm 4mm;
}

.scene-chat-row.jiayi .scene-bubble {
  background: var(--teal-light);
  border-right-color: var(--teal);
}

.scene-chat-row.carlos .scene-bubble {
  background: #f8e7e0;
  border-right-color: var(--terracotta);
}

.scene-speaker {
  display: block;
  margin-bottom: 0.45mm;
  color: var(--blue);
  font-size: 6pt;
  font-weight: 900;
  letter-spacing: 0.04em;
}

.scene-chat-row.jiayi .scene-speaker {
  color: var(--teal);
}

.scene-chat-row.carlos .scene-speaker {
  color: var(--terracotta);
}

.scene-dialogue-es {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Inter", Arial, sans-serif;
  font-size: 8.7pt;
  line-height: 1.24;
  font-weight: 780;
}

.scene-dialogue-zh {
  margin: 0.45mm 0 0;
  color: var(--muted);
  font-size: 6.35pt;
  line-height: 1.28;
}

.scene-learning-goal {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 2.5mm;
  align-items: start;
  margin-top: 1.8mm;
  padding: 1.8mm 2.5mm;
  color: var(--ink);
  background: #fff4d8;
  border-left: 1mm solid var(--mustard);
  border-radius: 0 3mm 3mm 0;
  font-size: 6.4pt;
  line-height: 1.4;
}

.scene-learning-goal strong {
  color: #855900;
}

.dialogue-image-row {
  display: grid;
  grid-template-columns: 36mm 1fr;
  gap: 4mm;
  align-items: stretch;
  margin-top: 4mm;
}

.dialogue-image-row img {
  width: 36mm;
  height: 24mm;
  object-fit: cover;
  border-radius: 3mm;
}

.dialogue-image-row p {
  align-self: center;
  margin: 0;
  font-size: 8.3pt;
  line-height: 1.55;
}

.dialogue-page .section-deck {
  margin-bottom: 2mm;
}

.dialogue-page .rule {
  display: none;
}

.dialogue-page .dialogue-image-row {
  grid-template-columns: 31mm 1fr;
  gap: 3mm;
  margin-top: 2.5mm;
}

.dialogue-page .dialogue-image-row img {
  width: 31mm;
  height: 20mm;
}

.dialogue-page .dialogue-image-row p {
  font-size: 7.8pt;
  line-height: 1.4;
}

.dialogue-page .dialogue-grid {
  gap: 2.5mm;
  margin-top: 2.8mm;
}

.dialogue-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 3mm;
  margin-top: 3.5mm;
}

.dialogue-card {
  padding: 2.5mm;
  background: var(--cream);
  border-radius: 3mm;
  break-inside: avoid;
  page-break-inside: avoid;
}

.dialogue-card:first-child {
  grid-column: 1 / -1;
}

.dialogue-card h3 {
  margin: 0 0 2mm;
  color: var(--ink);
  font-size: 9.5pt;
  line-height: 1.3;
}

.dialogue-line {
  display: grid;
  grid-template-columns: 6mm 1fr;
  gap: 2mm;
  margin-top: 1.15mm;
}

.role-dot {
  display: grid;
  width: 5.5mm;
  height: 5.5mm;
  place-items: center;
  color: var(--paper);
  background: var(--teal);
  border-radius: 50%;
  font-size: 6.2pt;
  font-weight: 900;
}

.dialogue-line.staff .role-dot {
  background: var(--blue);
}

.dialogue-es {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Inter", Arial, sans-serif;
  font-size: 8.15pt;
  line-height: 1.3;
  font-weight: 750;
}

.dialogue-zh {
  margin: 0.35mm 0 0;
  color: var(--muted);
  font-size: 6.4pt;
  line-height: 1.28;
}

.dialogue-note {
  margin: 1.4mm 0 0;
  padding-top: 1.1mm;
  border-top: 0.35mm solid var(--line);
  font-size: 6.1pt;
  line-height: 1.32;
}

.exercise-layout {
  display: grid;
  grid-template-columns: 48mm 1fr;
  gap: 4mm;
  margin-top: 4mm;
}

.exercise-image {
  width: 48mm;
  height: 33mm;
  object-fit: cover;
  border-radius: 3mm;
}

.choice-box {
  padding: 3.2mm;
  background: #fff5da;
  border-left: 1.2mm solid var(--mustard);
  border-radius: 0 3mm 3mm 0;
}

.choice-box h3,
.completion-box h3,
.quick-review h3 {
  margin: 0 0 2mm;
  color: var(--ink);
  font-size: 10pt;
}

.choice-options {
  display: grid;
  gap: 1.5mm;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: choices;
}

.choice-options li {
  counter-increment: choices;
  font-family: "Aptos", "Inter", Arial, sans-serif;
  font-size: 8pt;
  line-height: 1.35;
}

.choice-options li::before {
  content: counter(choices, upper-alpha) ". ";
  color: var(--terracotta);
  font-weight: 900;
}

details.answer {
  margin-top: 2mm;
  font-size: 7pt;
  line-height: 1.45;
}

details.answer summary {
  color: var(--teal);
  cursor: pointer;
  font-weight: 800;
}

.completion-box {
  margin-top: 4mm;
  padding: 3.5mm;
  background: var(--cream);
  border-radius: 3mm;
}

.completion-item {
  margin: 2mm 0 0;
  font-size: 8.3pt;
  line-height: 1.5;
}

.completion-item .es {
  color: var(--ink);
  font-family: "Aptos", "Inter", Arial, sans-serif;
  font-size: 10pt;
  font-weight: 750;
}

.blank {
  display: inline-block;
  min-width: 28mm;
  border-bottom: 0.45mm solid var(--ink);
}

.option-line {
  color: var(--muted);
  font-size: 7.2pt;
}

.quick-review {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3mm;
  margin-top: 4mm;
}

.review-card {
  padding: 2.5mm;
  border: 0.4mm solid var(--line);
  border-radius: 3mm;
}

.review-card p,
.review-card li {
  margin: 0;
  font-size: 7pt;
  line-height: 1.42;
}

.review-card ol,
.review-card ul {
  margin: 0;
  padding-left: 4mm;
}

.review-pair {
  display: grid;
  gap: 1.5mm;
}

.practice-review-page .section-deck {
  margin-bottom: 3mm;
}

.practice-review-page .rule {
  margin-top: 2mm;
  margin-bottom: 3mm;
}

.practice-review-page .exercise-layout {
  margin-top: 2.5mm;
}

.practice-review-page .exercise-image {
  height: 29mm;
}

.practice-review-page .choice-box {
  padding: 2.7mm;
}

.practice-review-page .choice-options {
  gap: 1mm;
}

.practice-review-page .choice-options li {
  font-size: 7.5pt;
  line-height: 1.28;
}

.practice-review-page .completion-box {
  margin-top: 3mm;
  padding: 2.8mm 3.2mm;
}

.practice-review-page .completion-item {
  margin-top: 1.2mm;
  font-size: 7.7pt;
  line-height: 1.38;
}

.practice-review-page .completion-item .es {
  font-size: 9.2pt;
}

.practice-review-page .quick-review {
  gap: 2.4mm;
  margin-top: 3mm;
}

.practice-review-page .review-card {
  padding: 2.2mm;
}

.practice-review-page .review-card h3 {
  margin-bottom: 1.3mm;
  font-size: 8.8pt;
}

.practice-review-page .review-card p,
.practice-review-page .review-card li {
  font-size: 6.15pt;
  line-height: 1.3;
}

.review-alert {
  padding-left: 2.5mm;
  border-left: 0.9mm solid var(--terracotta);
}

.review-tip {
  padding-left: 2.5mm;
  border-left: 0.9mm solid var(--mustard);
}

.emergency-page .section-title {
  color: var(--terracotta);
}

.emergency-banner {
  display: grid;
  grid-template-columns: 14mm 1fr;
  gap: 4mm;
  align-items: center;
  margin-top: 4mm;
  padding: 4mm;
  color: var(--paper);
  background: var(--terracotta);
  border-radius: 3mm;
}

.emergency-mark {
  display: grid;
  width: 12mm;
  height: 12mm;
  place-items: center;
  color: var(--terracotta);
  background: var(--paper);
  border-radius: 50%;
  font-size: 15pt;
  font-weight: 900;
}

.emergency-banner p {
  margin: 0;
  font-size: 8.5pt;
  line-height: 1.5;
}

.quick-phrase-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-template-rows: repeat(4, minmax(0, 1fr));
  flex: 1;
  min-height: 0;
  gap: 3mm;
  margin-top: 5mm;
}

.quick-phrase {
  min-height: 0;
  padding: 2.8mm 3mm;
  background: var(--paper);
  border: 0.4mm solid var(--line);
  border-left: 1.2mm solid var(--terracotta);
  border-radius: 0 3mm 3mm 0;
  break-inside: avoid;
}

.quick-phrase .es {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Inter", Arial, sans-serif;
  font-size: 10.2pt;
  line-height: 1.26;
  font-weight: 800;
}

.quick-phrase .zh {
  margin: 0.8mm 0 0;
  font-size: 7.4pt;
  line-height: 1.32;
}

.quick-phrase .context {
  display: inline-block;
  margin-top: 1mm;
  color: var(--terracotta);
  font-size: 6.2pt;
  font-weight: 800;
}

.print-note {
  margin-top: auto;
  padding: 2.5mm 3mm;
  color: var(--muted);
  background: var(--cream);
  border-radius: 3mm;
  font-size: 6.8pt;
  line-height: 1.38;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.gallery-body {
  min-width: 320px;
  color: var(--text);
  background: #e8eeeb;
}

.gallery-toolbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 64px;
  padding: 10px max(18px, calc((100vw - 1320px) / 2));
  color: var(--paper);
  background: var(--ink);
  border-bottom: 4px solid var(--mustard);
  max-height: 220px;
  overflow: hidden;
  transition: max-height 180ms ease, min-height 180ms ease, padding 180ms ease, border-width 180ms ease, opacity 160ms ease;
}

.gallery-toolbar a {
  padding: 8px 12px;
  color: var(--paper);
  border: 1px solid #729095;
  border-radius: 6px;
  text-decoration: none;
}

.gallery-toolbar .toolbar-hide-button {
  min-height: 34px;
  padding: 6px 10px;
  color: var(--paper);
  background: transparent;
  border: 1px solid #729095;
  border-radius: 6px;
  cursor: pointer;
}

.gallery-toolbar .toolbar-hide-button:hover,
.gallery-toolbar .toolbar-hide-button:focus-visible {
  border-color: var(--mustard);
  outline: 2px solid transparent;
}

.gallery-toolbar strong,
.gallery-toolbar span {
  display: block;
}

.gallery-toolbar strong {
  font-size: 15px;
}

.gallery-toolbar span {
  margin-top: 2px;
  color: #dbe4e1;
  font-size: 11px;
}

.scene-gallery-shell {
  width: min(1320px, calc(100% - 36px));
  margin: 0 auto;
  padding: 42px 0 70px;
}

.gallery-heading {
  max-width: 760px;
  margin-bottom: 28px;
}

.gallery-heading p {
  margin: 0 0 7px;
  color: var(--teal);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.14em;
}

.gallery-heading h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(28px, 4vw, 48px);
  line-height: 1.15;
}

.gallery-heading span {
  display: block;
  margin-top: 12px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.6;
}

.scene-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 24px;
}

.scene-card {
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
}

.scene-card img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: var(--cream);
}

.scene-card-copy {
  padding: 18px 20px 20px;
}

.scene-card-copy > span,
.scene-card-copy > small {
  color: var(--teal);
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.09em;
}

.scene-card-copy h2 {
  margin: 6px 0 8px;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.28;
}

.scene-card-copy p {
  min-height: 4.8em;
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

@media screen and (max-width: 1000px) {
  :root {
    --zoom: 0.82;
  }

  .book-preview {
    grid-template-columns: max-content;
  }

  .screen-toolbar {
    flex-wrap: wrap;
    padding-inline: max(14px, env(safe-area-inset-left)) max(14px, env(safe-area-inset-right));
  }

  .toolbar-brand small {
    display: none;
  }
}

@media screen and (max-width: 620px) {
  :root {
    --zoom: 1;
    background: #dfe4e2;
  }

  html,
  body {
    width: 100%;
    min-width: 0;
    overflow-x: clip;
  }

  body {
    padding-bottom: env(safe-area-inset-bottom);
    font-size: 16px;
  }

  img,
  svg,
  video,
  canvas {
    max-width: 100%;
    height: auto;
  }

  .screen-toolbar {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 8px;
    padding: max(8px, env(safe-area-inset-top)) max(10px, env(safe-area-inset-right)) 10px max(10px, env(safe-area-inset-left));
  }

  .toolbar-brand {
    grid-column: 1 / -1;
    min-width: auto;
    width: 100%;
  }

  .toolbar-brand strong {
    font-size: 15px;
    line-height: 1.3;
  }

  .toolbar-mark {
    width: 40px;
    height: 40px;
    flex: 0 0 40px;
  }

  .screen-toolbar > .toolbar-group:nth-of-type(2) {
    grid-column: 1 / -1;
  }

  .screen-toolbar > .toolbar-group:nth-of-type(2) .toolbar-label {
    display: none;
  }

  .screen-toolbar > .toolbar-group:nth-of-type(3),
  #modeToggle {
    display: none;
  }

  .toolbar-select {
    width: 100%;
    max-width: none;
  }

  .toolbar-button,
  .toolbar-select,
  .gallery-toolbar a,
  details.answer summary {
    min-height: 44px;
  }

  .toolbar-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 10px 12px;
    text-align: center;
  }

  .book-preview {
    display: block;
    width: 100%;
    padding: 16px 10px calc(56px + env(safe-area-inset-bottom));
  }

  .sheet {
    width: 100%;
    height: auto;
    min-height: 0;
    margin: 0 0 16px;
    overflow: visible;
    border-radius: 10px;
    zoom: 1 !important;
    scroll-margin-top: 176px;
  }

  .trim-page,
  .sheet[data-side="recto"] .trim-page,
  .sheet[data-side="verso"] .trim-page {
    position: relative;
    inset: auto;
    width: 100%;
    height: auto;
    min-height: 0;
    padding: 30px 18px 64px;
    overflow: visible;
  }

  .sheet.full-bleed .trim-page {
    width: 100%;
    height: auto;
  }

  .cover .trim-page {
    min-height: max(640px, calc(100dvh - 166px));
  }

  .page-main {
    flex: none;
    min-height: auto;
  }

  .folio {
    bottom: 22px;
    right: 18px;
    font-size: 14px;
  }

  .page-kicker,
  .eyebrow {
    margin-bottom: 10px;
    font-size: 13px;
  }

  .section-title {
    font-size: clamp(28px, 9vw, 36px);
    line-height: 1.22;
  }

  .section-deck {
    max-width: none;
    margin: 10px 0 18px;
    font-size: 17px;
    line-height: 1.7;
  }

  .rule {
    width: 72px;
    height: 4px;
    margin: 14px 0 20px;
  }

  .cover-content {
    min-height: max(640px, calc(100dvh - 166px));
    padding: 46px 22px 32px;
  }

  .series-label {
    padding: 8px 12px;
    font-size: 13px;
  }

  .cover-title {
    max-width: 100%;
    margin: 44px 0 16px;
    font-size: clamp(40px, 13vw, 54px);
  }

  .cover-subtitle {
    max-width: 100%;
    font-size: 19px;
    line-height: 1.65;
  }

  .cover-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
    margin-top: 28px;
  }

  .cover-stat {
    min-width: 0;
    padding: 10px 7px;
    text-align: center;
  }

  .cover-stat strong {
    font-size: 22px;
  }

  .cover-stat span {
    font-size: 13px;
    line-height: 1.3;
  }

  .cover-footer {
    gap: 16px;
  }

  .cover-footer p {
    max-width: none;
    font-size: 16px;
    line-height: 1.65;
  }

  .cover-badge {
    width: 70px;
    height: 70px;
    flex: 0 0 70px;
    font-size: 16px;
  }

  .inside-cover {
    min-height: max(480px, 70dvh);
    padding: 48px 22px;
  }

  .inside-cover blockquote {
    max-width: 100%;
    font-size: 28px;
  }

  .inside-cover small {
    margin-top: 24px;
    font-size: 15px;
  }

  .title-page {
    min-height: 70dvh;
    justify-content: center;
  }

  .title-page .book-title {
    max-width: 100%;
    font-size: clamp(34px, 11vw, 46px);
  }

  .title-page .book-subtitle {
    max-width: 100%;
    margin-top: 18px;
    font-size: 18px;
  }

  .title-meta,
  .panel-grid,
  .icon-list,
  .goals-list,
  .scene-usage-list,
  .survival-grid,
  .sentence-grid,
  .dialogue-grid,
  .exercise-layout,
  .quick-review,
  .quick-phrase-list {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: none;
  }

  .title-meta {
    gap: 12px;
    margin-top: 36px;
  }

  .title-meta div,
  .panel,
  .sample-card,
  .copyright-box,
  .goals-box,
  .scene-usage-box,
  .choice-box,
  .completion-box,
  .review-card,
  .quick-phrase {
    padding: 18px;
    border-radius: 8px;
  }

  .title-meta strong,
  .panel h3,
  .sample-card .zh,
  .goals-box h2,
  .scene-usage-box h2,
  .choice-box h3,
  .completion-box h3,
  .quick-review h3 {
    font-size: 19px;
  }

  .title-meta span,
  .copyright-box,
  .toc-copy small,
  .panel p,
  .panel li,
  .icon-row span,
  .sample-card .note,
  .register-table > div,
  .region-callout,
  .route-copy span,
  .chapter-intro,
  .goals-list li,
  .scene-usage-when,
  .survival-card .zh,
  .sentence-zh,
  .sentence-usage,
  .replacement-box,
  .region-note,
  .dialogue-image-row p,
  .dialogue-es,
  .dialogue-zh,
  .dialogue-note,
  .choice-options li,
  details.answer,
  .completion-item,
  .option-line,
  .review-card p,
  .review-card li,
  .practice-review-page .choice-options li,
  .practice-review-page .completion-item,
  .practice-review-page .review-card p,
  .practice-review-page .review-card li,
  .emergency-banner p,
  .quick-phrase .zh,
  .print-note {
    font-size: 16px;
    line-height: 1.68;
  }

  .toc-list,
  .panel-grid,
  .icon-list,
  .survival-grid,
  .sentence-grid,
  .dialogue-grid,
  .quick-phrase-list {
    gap: 14px;
    margin-top: 22px;
  }

  .survival-page .section-deck,
  .sentence-page .section-deck {
    margin-bottom: 8px;
  }

  .survival-page .rule,
  .sentence-page .rule {
    margin: 8px 0 12px;
  }

  .survival-page .survival-grid,
  .sentence-page .sentence-grid {
    margin-top: 0;
  }

  .sentence-page .sentence-grid {
    grid-template-rows: none;
  }

  .sentence-page .replacement-box {
    margin-top: 12px;
  }

  .toc-item {
    grid-template-columns: 34px minmax(0, 1fr) auto;
    gap: 10px;
    padding: 14px 0;
  }

  .toc-number,
  .toc-page {
    font-size: 16px;
  }

  .toc-copy strong {
    font-size: 18px;
  }

  .icon-row {
    grid-template-columns: 38px minmax(0, 1fr);
    gap: 12px;
    padding: 14px 0;
  }

  .icon-chip,
  .route-dot,
  .survival-index,
  .role-dot {
    width: 32px;
    height: 32px;
    font-size: 13px;
  }

  .icon-row strong,
  .route-copy strong {
    font-size: 18px;
  }

  .chip,
  .speaker-badge,
  .register-badge,
  .region-badge,
  .purpose {
    min-height: 28px;
    padding: 6px 9px;
    font-size: 13px;
    line-height: 1.2;
  }

  .sample-card .es,
  .sentence-es {
    font-size: 22px;
    line-height: 1.42;
  }

  .register-table {
    grid-template-columns: minmax(0, 1fr);
    margin-top: 22px;
    border-radius: 8px;
  }

  .register-table > div {
    padding: 14px;
  }

  .register-table > div:nth-child(odd) {
    border-bottom: 0;
    font-size: 16px;
  }

  .register-table > div:nth-child(even) {
    border-bottom: 1px solid var(--line);
  }

  .route {
    gap: 18px;
    margin-top: 28px;
  }

  .route-step {
    grid-template-columns: 36px minmax(0, 1fr);
    gap: 14px;
    min-height: 0;
  }

  .route-step:not(:last-child) .route-dot::after {
    display: none;
  }

  .chapter-heading {
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 14px;
  }

  .chapter-number {
    width: 50px;
    height: 50px;
    font-size: 20px;
  }

  .chapter-title {
    font-size: clamp(30px, 9vw, 38px);
  }

  .hero-frame,
  .hero-frame img {
    width: 100%;
    height: auto;
    min-height: 0;
    aspect-ratio: 4 / 3;
  }

  .hero-frame img {
    object-fit: cover;
  }

  .chapter-opener .hero-frame {
    border-radius: 8px 8px 0 0;
  }

  .chapter-opener .scene-usage-box {
    border-radius: 0 0 8px 8px;
  }

  .hero-caption {
    right: 10px;
    bottom: 10px;
    max-width: calc(100% - 20px);
    padding: 7px 10px;
    font-size: 13px;
  }

  .scene-usage-list {
    gap: 12px;
  }

  .scene-usage-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
    padding: 16px;
    border-radius: 8px;
  }

  .scene-usage-phrase {
    font-size: 18px;
    line-height: 1.42;
  }

  .scene-usage-when strong {
    margin-bottom: 4px;
    font-size: 13px;
  }

  .scene-dialogue-intro {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
  }

  .scene-dialogue-intro img {
    width: 100%;
    height: auto;
    aspect-ratio: 4 / 3;
  }

  .scene-dialogue-intro .page-kicker {
    font-size: 13px;
  }

  .scene-dialogue-intro h1 {
    font-size: 28px;
  }

  .scene-dialogue-intro div > p:last-child,
  .scene-dialogue-guide,
  .scene-dialogue-zh,
  .scene-learning-goal {
    font-size: 16px;
    line-height: 1.6;
  }

  .scene-chat {
    gap: 12px;
    margin-top: 16px;
  }

  .scene-bubble {
    max-width: 94%;
    padding: 16px;
    border-radius: 8px;
  }

  .scene-speaker {
    margin-bottom: 5px;
    font-size: 13px;
  }

  .scene-dialogue-es {
    font-size: 19px;
    line-height: 1.45;
  }

  .scene-learning-goal {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
    margin-top: 16px;
    padding: 16px;
  }

  .survival-page .survival-grid {
    display: grid;
    flex: none;
    gap: 14px;
  }

  .survival-card,
  .survival-page .survival-card {
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 12px;
    min-height: 0;
    padding: 16px;
  }

  .survival-card .es,
  .survival-page .survival-card .es {
    font-size: 20px;
    line-height: 1.42;
  }

  .sentence-grid {
    display: grid;
    flex: none;
  }

  .sentence-card {
    min-height: 0;
    padding: 18px;
  }

  .sentence-meta {
    gap: 7px;
    margin-bottom: 14px;
  }

  .replacement-box {
    margin-top: 16px;
    padding-top: 14px;
  }

  .dialogue-image-row,
  .dialogue-page .dialogue-image-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
    margin-top: 16px;
  }

  .dialogue-image-row img,
  .dialogue-page .dialogue-image-row img {
    width: 100%;
    height: auto;
    aspect-ratio: 4 / 3;
  }

  .dialogue-card,
  .dialogue-card:first-child {
    grid-column: auto;
    padding: 16px;
  }

  .dialogue-card h3 {
    font-size: 19px;
  }

  .dialogue-line {
    grid-template-columns: 32px minmax(0, 1fr);
    gap: 10px;
    margin-top: 12px;
  }

  .dialogue-es {
    color: var(--ink);
    font-size: 18px;
    line-height: 1.5;
  }

  .dialogue-zh {
    margin-top: 4px;
  }

  .exercise-image,
  .practice-review-page .exercise-image {
    width: 100%;
    height: auto;
    aspect-ratio: 4 / 3;
  }

  .choice-options,
  .review-pair {
    gap: 12px;
  }

  .choice-options li,
  .practice-review-page .choice-options li {
    padding: 4px 0;
  }

  details.answer summary {
    display: flex;
    align-items: center;
  }

  .completion-item .es,
  .practice-review-page .completion-item .es {
    font-size: 19px;
    line-height: 1.55;
  }

  .quick-review {
    gap: 14px;
  }

  .emergency-banner {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 14px;
    padding: 16px;
  }

  .emergency-mark {
    width: 42px;
    height: 42px;
    font-size: 24px;
  }

  .quick-phrase .es {
    font-size: 20px;
    line-height: 1.45;
  }

  .quick-phrase .context {
    margin-top: 8px;
    font-size: 14px;
  }

  .print-note {
    margin-top: 18px;
    padding: 16px;
  }

  .gallery-toolbar {
    gap: 12px;
    min-height: 0;
    padding: max(10px, env(safe-area-inset-top)) max(12px, env(safe-area-inset-right)) 10px max(12px, env(safe-area-inset-left));
  }

  .gallery-toolbar a {
    display: inline-flex;
    align-items: center;
    flex: 0 0 auto;
    padding: 9px 11px;
  }

  .gallery-toolbar strong {
    font-size: 14px;
  }

  .gallery-toolbar span {
    display: none;
  }

  .scene-gallery-shell {
    width: calc(100% - 24px);
    padding: 28px 0 calc(56px + env(safe-area-inset-bottom));
  }

  .gallery-heading h1 {
    font-size: 32px;
  }

  .gallery-heading span,
  .scene-card-copy p {
    min-height: 0;
    font-size: 16px;
    line-height: 1.65;
  }

  .scene-gallery {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .scene-card-copy h2 {
    font-size: 22px;
  }

  .not-found {
    padding: 40px 20px calc(40px + env(safe-area-inset-bottom));
  }
}

.not-found {
  display: grid;
  min-height: 100dvh;
  place-content: center;
  justify-items: start;
  padding: 48px;
  color: var(--text);
  background: var(--cream);
}

.not-found > span {
  color: var(--terracotta);
  font-size: 18px;
  font-weight: 900;
  letter-spacing: 0.14em;
}

.not-found h1 {
  margin: 10px 0;
  color: var(--ink);
  font-size: clamp(34px, 7vw, 64px);
}

.not-found p {
  max-width: 560px;
  margin: 0 0 24px;
  font-size: 17px;
  line-height: 1.7;
}

.not-found a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  padding: 10px 16px;
  color: var(--paper);
  background: var(--teal);
  border-radius: 8px;
  font-weight: 800;
  text-decoration: none;
}

@page {
  size: 154mm 216mm;
  margin: 0;
  bleed: 3mm;
  marks: crop;
}

@media print {
  :root {
    --zoom: 1;
    background: white;
  }

  html,
  body {
    margin: 0;
    padding: 0;
    background: white;
  }

  .screen-toolbar,
  .gallery-toolbar,
  .toolbar-reveal {
    display: none !important;
  }

  .book-preview {
    display: block;
    padding: 0;
  }

  .sheet {
    width: 154mm;
    height: 216mm;
    margin: 0;
    box-shadow: none;
    zoom: 1;
    break-after: page;
    page-break-after: always;
  }

  .sheet:last-child {
    break-after: auto;
    page-break-after: auto;
  }

  details.answer:not([open]) > *:not(summary) {
    display: block;
  }

  details.answer summary {
    display: none;
  }

  .sentence-card,
  .dialogue-card,
  .quick-phrase,
  .panel,
  .review-card {
    break-inside: avoid;
    page-break-inside: avoid;
  }
}