:root {
  --color-bg: #ffffff;
  --color-surface: #ffffff;
  --color-fg: #2a2a2a;
  --color-title: #1a3d7c;
  --color-muted: #6b6b6b;
  --color-accent: #ff4b3e;
  --color-border: #d9d9d9;
  --color-line: #e4e4e4;
  --font-sans: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  --font-display: Palatino, "Palatino Linotype", "Songti SC", "Noto Serif CJK SC", Georgia, serif;
  --radius-pill: 999px;
  --index-h: calc(3.5rem + env(safe-area-inset-top, 0px));
  --track-w: 3rem;
  --rail-w: clamp(16rem, 22vw, 30rem);
  --thumb-size: 1.75rem;
  --count: 12;
  --chrome-gap: 4.75rem;
  --ink: #1c1916;
  --quiet: #5e574e;
  --rule: #e0d6c6;
  --warm: #7a2e24;
  --warm-soft: #f6e7e2;
  --serif: Palatino, "Palatino Linotype", "Iowan Old Style", "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "Noto Serif SC", serif;
}

html[data-client="desktop"] {
  --rail-w: clamp(16rem, 22vw, 30rem);
}

html[data-client="android"] {
  --rail-w: min(11rem, 42vw);
}

* { box-sizing: border-box; }

html {
  background: var(--color-bg);
  color: var(--color-fg);
  color-scheme: light;
  scrollbar-width: none;
}

html::-webkit-scrollbar { display: none; }

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-fg);
}

button, select { font: inherit; }

::selection {
  background: var(--color-accent);
  color: #ffffff;
}

#library { display: none !important; }

.index-bar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: stretch;
  height: var(--index-h);
  padding-top: env(safe-area-inset-top, 0px);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  user-select: none;
}

.brand {
  position: relative;
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 0.35rem;
  width: auto;
  padding: 0 0.75rem 0 1rem;
  border-right: 1px solid var(--color-border);
}

.file-pick { display: flex; align-items: center; }

.select-probe {
  position: absolute;
  visibility: hidden;
  white-space: nowrap;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  pointer-events: none;
}

.file-pick select {
  width: 8rem;
  max-width: none;
  padding: 0.2rem 1.15rem 0.2rem 0;
  border: 0;
  background: transparent
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 8'%3E%3Cpath fill='%231a3d7c' d='M1 1l5 5 5-5'/%3E%3C/svg%3E")
    right center / 0.7rem no-repeat;
  color: var(--color-title);
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  appearance: none;
  cursor: pointer;
}

.lang-switch {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  margin: 0;
  padding: 0.28rem 0.7rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: #ffffff;
  color: var(--color-title);
  font-size: 0.8125rem;
  font-weight: 650;
  line-height: 1.2;
  white-space: nowrap;
  cursor: pointer;
}

.lang-switch-kicker {
  color: var(--color-muted);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

#lang-switch-target { color: var(--color-accent); }

.client-switch {
  display: inline-flex;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}

.client-btn {
  margin: 0;
  border: 0;
  background: transparent;
  color: var(--color-title);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 0.32rem 0.55rem;
  line-height: 1.2;
  cursor: pointer;
}

.client-btn.is-on {
  background: var(--color-title);
  color: #ffffff;
}

.file-pick select:focus-visible,
.lang-switch:focus-visible,
.client-btn:focus-visible,
.chip:focus-visible,
.track:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.chips {
  display: flex;
  flex: 1;
  align-items: stretch;
  gap: 0.25rem;
  min-width: 0;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  padding: 0.4rem 0.6rem;
  scrollbar-width: none;
}

.chips::-webkit-scrollbar { display: none; }

.chip, .rail-item, .track { -webkit-tap-highlight-color: transparent; }

.chip {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 0.4rem;
  padding: 0 0.8rem;
  border: 0;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-title);
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
  cursor: pointer;
}

.chip-num, .rail-num, .num, .page-num { font-variant-numeric: tabular-nums; }

.chip-num, .rail-num, .kicker .num { color: var(--color-accent); }

.chip-num { font-size: 0.75rem; }

.chip-name, .rail-name, .slide-title { color: var(--color-title); }

.chip.is-active { box-shadow: inset 0 -2px 0 var(--color-accent); }

.scroller {
  position: fixed;
  z-index: 1;
  top: var(--index-h);
  right: 0;
  bottom: 0;
  left: 0;
  box-sizing: border-box;
  overflow-x: hidden;
  overflow-y: auto;
  padding-right: var(--track-w);
  overscroll-behavior: contain;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.scroller::-webkit-scrollbar { display: none; }

.chapter {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  width: 100%;
  margin: 0;
  padding: 1.35rem 1.25rem 1rem 1.35rem;
}

.chapter + .chapter { border-top: 1px solid var(--color-line); }

.chapter.is-current { box-shadow: inset 3px 0 0 var(--color-accent); }

.kicker {
  margin: 0;
  color: var(--color-muted);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.slide-title {
  margin: 0.35rem 0 0;
  font-family: var(--font-display);
  font-size: 1.875rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.12;
}

.folio {
  display: flex;
  justify-content: flex-end;
  margin: 1.25rem 0 0;
  padding-top: 0.75rem;
  color: var(--color-muted);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.page-num { color: var(--color-muted); }

.chapter.is-current .page-num { color: var(--color-accent); }

.rail {
  position: fixed;
  z-index: 40;
  top: calc(var(--index-h) + 4.5rem);
  right: 0;
  display: flex;
  width: var(--track-w);
  height: calc(100vh - var(--index-h) - var(--chrome-gap) - 4.5rem);
  height: calc(100dvh - var(--index-h) - var(--chrome-gap) - 4.5rem);
  user-select: none;
  touch-action: none;
}

.rail.is-open {
  width: var(--rail-w);
  border-left: 1px solid var(--color-border);
  background: var(--color-surface);
}

.rail-list {
  display: none;
  flex: 1;
  flex-direction: column;
  min-width: 0;
  margin: 0;
  padding: 0.35rem 0;
  list-style: none;
  pointer-events: none;
}

.rail.is-open .rail-list { display: flex; }

.rail-list li {
  display: flex;
  flex: 1 1 0;
  min-height: 0;
}

.rail-item {
  display: flex;
  flex: 1;
  align-items: center;
  gap: 0.35rem;
  min-width: 0;
  padding: 0 0.35rem 0 0.6rem;
  color: var(--color-title);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.2;
}

.rail-num { flex: 0 0 1.15rem; }

.rail-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.rail-item.is-active { box-shadow: inset 3px 0 0 var(--color-accent); }

.track {
  position: relative;
  flex: 0 0 var(--track-w);
  margin-left: auto;
  touch-action: none;
  cursor: grab;
  outline: none;
}

.track.is-dragging { cursor: grabbing; }

.track-line {
  position: absolute;
  top: calc(var(--thumb-size) / 2 + (100% - var(--thumb-size)) / var(--count) / 2);
  bottom: calc(var(--thumb-size) / 2 + (100% - var(--thumb-size)) / var(--count) / 2);
  left: 50%;
  width: 2px;
  margin-left: -1px;
  border-radius: var(--radius-pill);
  background: var(--color-border);
  pointer-events: none;
}

.thumb {
  position: absolute;
  left: 50%;
  display: grid;
  width: var(--thumb-size);
  height: var(--thumb-size);
  margin-left: calc(var(--thumb-size) / -2);
  place-items: center;
  pointer-events: auto;
  touch-action: none;
  cursor: grab;
  top: calc((var(--p, 0) * (var(--count) - 1) + 0.5) / var(--count) * (100% - var(--thumb-size)));
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  color: #ffffff;
  box-shadow: 0 2px 8px color-mix(in srgb, black 28%, transparent);
}

.thumb svg {
  width: 1rem;
  height: 1rem;
  pointer-events: none;
  touch-action: none;
}

.quire {
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.65;
}

.quire-zh,
.quire-zh .type-h1,
.quire-zh .type-h2,
.quire-zh .type-paragraph,
.quire-zh .split-lead,
.quire-zh .split-body,
.quire-zh .quote-block p {
  font-family: "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "Noto Serif SC", Palatino, serif;
}

.quire-zh .kicker,
.quire-zh .figcap,
.quire-zh .quote-by,
.quire-zh .folio,
.quire-zh .callout p,
.quire-zh .step-list li::before {
  font-family: var(--font-sans);
  letter-spacing: 0.04em;
  text-transform: none;
}

.type-h1,
.type-h2,
.type-paragraph,
.quote-block p,
.callout p,
.split-lead,
.split-body { white-space: pre-wrap; }

.type-h1 {
  margin: 0.35rem 0 0;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 0.55rem;
  color: var(--ink);
  font-size: 2.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.12;
}

.type-h2 {
  margin: 0.35rem 0 0;
  border-left: 3px solid var(--warm);
  padding-left: 0.75rem;
  color: var(--ink);
  font-size: 1.55rem;
  font-weight: 600;
  line-height: 1.25;
}

.type-paragraph { margin: 0.9rem 0 0; text-indent: 1.5em; }

.chapter > .type-h1,
.chapter > .type-h2,
.chapter > .type-paragraph,
.chapter > .pair,
.chapter > .bullet-list,
.chapter > .step-list,
.chapter > .callout,
.chapter > .quote-block,
.chapter > .bleed,
.chapter > .split { margin-top: 1rem; }

.chapter > .type-paragraph:first-of-type { margin-top: 1rem; }

.stack { display: grid; gap: 0.9rem; }

.bullet-list,
.step-list { margin: 1rem 0 0; padding: 0; list-style: none; }

.bullet-list li {
  position: relative;
  margin: 0.55rem 0;
  padding-left: 1.15rem;
}

.bullet-list li::before {
  content: "";
  position: absolute;
  top: 0.62em;
  left: 0;
  width: 0.38rem;
  height: 0.38rem;
  background: var(--warm);
}

.step-list { counter-reset: step; border-bottom: 1px solid var(--rule); }

.step-list li {
  counter-increment: step;
  display: grid;
  grid-template-columns: 2.75rem minmax(0, 1fr);
  gap: 0.75rem;
  align-items: baseline;
  padding: 0.8rem 0;
  border-top: 1px solid var(--rule);
}

.step-list li::before {
  content: counter(step, decimal-leading-zero);
  color: var(--warm);
  font-family: var(--serif);
  font-size: 1.35rem;
  line-height: 1;
}

.pair {
  display: grid;
  align-items: start;
  gap: 1.15rem;
  margin-top: 1rem;
}

.pair figure, .bleed { margin: 0; }

.shot { display: block; width: 100%; object-fit: cover; background: #f3efe6; }

.shot-pair { height: 16rem; }

.shot-bleed { height: 18rem; }

.figcap, .quote-by {
  color: var(--quiet);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  line-height: 1.45;
}

.figcap { margin: 0.6rem 0 0; }

.bleed { margin-right: -1.25rem; margin-left: -1.35rem; }

.bleed .figcap { padding: 0.7rem 1.25rem 0 1.35rem; }

.callout {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.85rem;
  align-items: start;
  margin-top: 1rem;
  padding: 1rem;
  background: var(--warm-soft);
}

.callout p {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.02rem;
  line-height: 1.5;
}

.callout-mark {
  display: grid;
  width: 2.25rem;
  height: 2.25rem;
  place-items: center;
  border: 1.5px solid var(--warm);
  border-radius: 999px;
  color: var(--warm);
  font-family: var(--serif);
  font-size: 1.35rem;
  line-height: 1;
}

.quote-block { margin: 1rem 0 0; }

.quote-block::before {
  content: "“";
  display: block;
  height: 1.4rem;
  color: var(--warm);
  font-family: var(--serif);
  font-size: 4rem;
  line-height: 0.8;
}

.quire-zh .quote-block::before {
  content: "「";
  height: auto;
  font-size: 1.7rem;
  line-height: 1;
}

.quote-block p {
  margin: 0;
  font-size: 1.5rem;
  font-style: italic;
  line-height: 1.35;
}

.quire-zh .quote-block p { font-style: normal; }

.quire-fr .quote-block::before {
  content: "«";
  height: auto;
  font-size: 2.4rem;
  line-height: 1;
}

.quire-hi,
.quire-hi .type-h1,
.quire-hi .type-h2,
.quire-hi .type-paragraph,
.quire-hi .split-lead,
.quire-hi .split-body,
.quire-hi .quote-block p {
  font-family: "Nirmala UI", "Noto Serif Devanagari", "Mangal", Palatino, serif;
}

.quire-th,
.quire-th .type-h1,
.quire-th .type-h2,
.quire-th .type-paragraph,
.quire-th .split-lead,
.quire-th .split-body,
.quire-th .quote-block p {
  font-family: "Leelawadee UI", "Noto Serif Thai", "Thonburi", Tahoma, serif;
}

.quire-hi .kicker,
.quire-hi .figcap,
.quire-hi .quote-by,
.quire-hi .folio,
.quire-hi .callout p,
.quire-th .kicker,
.quire-th .figcap,
.quire-th .quote-by,
.quire-th .folio,
.quire-th .callout p,
.quire-fr .kicker,
.quire-fr .quote-by {
  letter-spacing: 0.04em;
  text-transform: none;
}

.load-note {
  position: fixed;
  z-index: 50;
  right: 1.25rem;
  bottom: 1.25rem;
  left: 1.25rem;
  max-width: 36rem;
  margin: 0 auto;
  padding: 0.9rem 1rem;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-fg);
  line-height: 1.45;
}

.quote-by {
  margin: 0.9rem 0 0;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.split {
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
}

.split-lead, .split-body { margin: 0; }

.split-lead {
  padding: 1rem 1.05rem;
  background: var(--warm-soft);
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.35;
}

@media (min-width: 40rem) {
  .chapter { padding: 1.75rem 2.5rem 1.25rem 2rem; }
  .slide-title { font-size: 2.25rem; }
  .type-h1 { font-size: 2.6rem; }
  .quire { font-size: 1.2rem; }
  .pair { grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr); }
  .shot-bleed { height: 22rem; }
  .bleed { margin-right: -2.5rem; margin-left: -2rem; }
  .bleed .figcap { padding-right: 2.5rem; padding-left: 2rem; }
  .split { grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: 1.4rem; }
  .rail-item { padding-left: 0.85rem; font-size: 0.875rem; }
  .rail-num { flex-basis: 1.4rem; }
}

@media (hover: hover) {
  .chip:hover,
  .lang-switch:hover { background: #f3f3f3; }
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}