/* ══════════════════════════════════════════════════════
   九游赛场 · 共享样式 /assets/site.css
   绿茵夜场 · 堆叠面板 · 侧边轨道 · 精密网格
   ══════════════════════════════════════════════════════ */

/* ── 1. reset ───────────────────────────────────────── */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body, h1, h2, h3, h4, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
img { height: auto; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
main { display: block; }
[hidden] { display: none !important; }

/* ── 2. 变量 ────────────────────────────────────────── */
:root {
  --turf: #0B5D1E;
  --night: #062E10;
  --line: #F4F7F0;
  --stand: #FFF6E8;
  --neon: #7FE03B;
  --silver: #C3CBC4;
  --alert: #FF6A1A;
  --tactical: #7A8C7E;
  --ink: #101513;
  --mist: rgba(127, 224, 59, 0.12);
  --line-soft: rgba(195, 203, 196, 0.26);
  --line-faint: rgba(195, 203, 196, 0.14);

  --rail-w: 72px;
  --topbar-h: 64px;
  --width: 1200px;
  --gutter: clamp(18px, 4vw, 56px);
  --radius: 0px;

  --font-head: "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC",
    "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: var(--font-head);
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas,
    "Liberation Mono", "Courier New", monospace;

  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --scroll-progress: 0;
}

/* ── 3. 基础排版 ────────────────────────────────────── */
body {
  margin: 0;
  padding-left: var(--rail-w);
  background: var(--ink);
  color: var(--line);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  word-break: break-word;
  overflow-x: hidden;
}

html.is-nav-open,
html.is-nav-open body { overflow: hidden; }

:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 3px;
}

.display,
.h2,
.h3 { font-family: var(--font-head); text-align: left; }

.display {
  font-size: clamp(38px, 7vw, 88px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -0.02em;
  margin: 0 0 0.4em;
}

.h2 {
  font-size: clamp(26px, 3.6vw, 44px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.01em;
  margin: 0 0 0.5em;
}

.h3 {
  font-size: clamp(19px, 2vw, 24px);
  font-weight: 700;
  line-height: 1.32;
  margin: 0 0 0.6em;
}

.lead {
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.8;
  max-width: 34em;
  opacity: 0.92;
}

.prose { max-width: 38em; }
.prose p { margin: 0 0 1.1em; }
.prose p:last-child { margin-bottom: 0; }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  display: inline-block;
  transform: skewX(-3deg);
  transform-origin: left center;
  letter-spacing: -0.02em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--neon);
  margin: 0 0 16px;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}

.eyebrow--dark { color: var(--turf); }

/* ── 4. 跳转链接 ────────────────────────────────────── */
.skip-link {
  position: fixed;
  top: 0;
  left: var(--rail-w);
  z-index: 200;
  padding: 10px 20px;
  background: var(--neon);
  color: var(--night);
  font-size: 14px;
  font-weight: 800;
  transform: translateY(-130%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus { transform: translateY(0); }

/* ── 5. 侧边轨道 / 页头 ─────────────────────────────── */
.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--rail-w);
  z-index: 60;
  display: flex;
  flex-direction: column;
  background: linear-gradient(180deg, var(--night) 0%, #0B5D1E 100%);
  color: var(--silver);
  border-right: 1px solid var(--line-soft);
  overflow: hidden;
}

.rail::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background-image: repeating-linear-gradient(
    180deg,
    rgba(195, 203, 196, 0.34) 0 1px,
    transparent 1px 14px
  );
  pointer-events: none;
}

.rail__scrim {
  display: none;
}

.rail__progress {
  position: absolute;
  top: 0;
  right: 0;
  width: 2px;
  height: 100%;
  background: var(--neon);
  opacity: 0.85;
  transform-origin: top center;
  transform: scaleY(var(--scroll-progress));
  pointer-events: none;
  z-index: 6;
}

.rail__topbar {
  position: relative;
  z-index: 8;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  flex: 0 0 auto;
  border-bottom: 1px solid var(--line-faint);
}

.rail__lockup {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 16px 6px 14px;
  color: var(--line);
}

.rail__mark {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  background: var(--neon);
  color: var(--night);
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 14px;
  line-height: 1;
}

.rail__word {
  writing-mode: vertical-rl;
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 0.2em;
  line-height: 1;
  color: var(--line);
}

.rail__toggle { display: none; }

.rail__drawer {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

.rail__drawer::-webkit-scrollbar { width: 3px; }
.rail__drawer::-webkit-scrollbar-thumb { background: var(--tactical); }

.rail__nav {
  flex: 0 0 auto;
  padding: 10px 0 8px;
}

.rail__item + .rail__item { margin-top: 2px; }

.rail__link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 9px 4px;
  color: var(--silver);
  font-size: 12px;
  letter-spacing: 0.04em;
  line-height: 1.3;
  border-left: 2px solid transparent;
  transition: background 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease);
}

.rail__link:hover {
  background: var(--mist);
  color: var(--line);
}

.rail__link[aria-current="page"] {
  background: rgba(127, 224, 59, 0.1);
  border-left-color: var(--neon);
  color: var(--neon);
}

.rail__idx {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.12em;
  color: var(--tactical);
}

.rail__link[aria-current="page"] .rail__idx { color: var(--neon); }

.rail__label { display: block; }

.rail__chapters {
  flex: 0 0 auto;
  padding: 10px 5px 12px;
  border-top: 1px dashed var(--line-faint);
}

.rail__chapters-title {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.16em;
  color: var(--tactical);
  text-align: center;
}

.rail__chapter {
  display: block;
  width: 100%;
  padding: 6px 2px;
  text-align: center;
  color: var(--tactical);
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
}

.rail__chapter:hover { color: var(--neon); background: var(--mist); }

.rail__chapter[aria-current="true"] {
  color: var(--neon);
  background: var(--mist);
}

.rail__chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.1em;
  opacity: 0.8;
}

.rail__chapter-label {
  display: block;
  font-size: 11px;
  line-height: 1.35;
  letter-spacing: 0.02em;
}

.rail__foot {
  margin-top: auto;
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 14px 6px 18px;
  border-top: 1px solid var(--line-faint);
}

.rail__slogan {
  writing-mode: vertical-rl;
  margin: 0;
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--tactical);
  line-height: 1;
}

.rail__cta {
  writing-mode: vertical-rl;
  display: inline-block;
  padding: 14px 7px;
  background: var(--neon);
  color: var(--night);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  line-height: 1;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.rail__cta:hover { background: var(--stand); color: var(--turf); }

.rail__to-top {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-soft);
  color: var(--silver);
  font-size: 14px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.24s var(--ease), visibility 0.24s var(--ease),
    background 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease);
}

.rail__to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
}

.rail__to-top:hover {
  background: var(--neon);
  border-color: var(--neon);
  color: var(--night);
}

.rail__lang {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.14em;
  color: var(--tactical);
}

@media (max-height: 860px) {
  .rail__slogan { display: none; }
}

/* ── 6. 面板 / 容器 / 网格 ──────────────────────────── */
.container {
  width: 100%;
  max-width: var(--width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.panel {
  position: relative;
  padding: clamp(36px, 5.4vw, 84px) 0;
  background: var(--line);
  color: var(--ink);
  border-top: 1px solid rgba(16, 21, 19, 0.14);
}

.panel--turf {
  background: var(--turf);
  color: var(--line);
  border-top-color: var(--line-soft);
}

.panel--night {
  background: var(--night);
  color: var(--line);
  border-top-color: var(--line-faint);
}

.panel--stand {
  background: var(--stand);
  color: var(--ink);
  border-top-color: rgba(16, 21, 19, 0.14);
}

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.tick-rule {
  height: 8px;
  color: inherit;
  background-image: repeating-linear-gradient(
    90deg,
    currentColor 0 1px,
    transparent 1px 14px
  );
  opacity: 0.35;
}

/* ── 7. 按钮与标签 ──────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
  border: 1px solid transparent;
  border-radius: var(--radius);
  background: var(--neon);
  color: var(--night);
  transition: background 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease), transform 0.18s var(--ease);
}

.btn:hover { background: var(--stand); color: var(--turf); transform: translateX(3px); }

.btn--ghost {
  background: transparent;
  color: var(--line);
  border-color: var(--line-soft);
}

.btn--ghost:hover {
  background: var(--mist);
  color: var(--neon);
  border-color: var(--neon);
}

.btn--dark {
  background: var(--night);
  color: var(--line);
}

.btn--dark:hover { background: var(--turf); color: var(--stand); }

.btn--alert {
  background: var(--alert);
  color: var(--ink);
}

.btn--alert:hover { background: var(--stand); color: var(--alert); }

.btn--block {
  display: flex;
  width: 100%;
  justify-content: space-between;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.5;
  border: 1px solid var(--line-soft);
  color: var(--silver);
  border-radius: var(--radius);
}

.tag--neon {
  border-color: var(--neon);
  background: var(--mist);
  color: var(--neon);
}

.tag--alert {
  border-color: var(--alert);
  color: var(--alert);
}

/* ── 8. 面包屑 ──────────────────────────────────────── */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--tactical);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--silver);
  opacity: 0.6;
}

.breadcrumb a {
  color: var(--tactical);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.breadcrumb a:hover {
  color: var(--neon);
  border-bottom-color: currentColor;
}

/* ── 9. 图片容器基础（页面阶段放置占位） ───────────── */
.media-frame {
  position: relative;
  overflow: hidden;
  background: var(--night);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(127, 224, 59, 0.16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(127, 224, 59, 0.16) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: 0.55;
}

.media-frame img,
.media-frame picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--3x4 { aspect-ratio: 3 / 4; }

.media-frame__caption {
  padding: 10px 12px;
  background: var(--night);
  border-top: 1px solid var(--line-faint);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--tactical);
}

/* ── 10. 页脚 ───────────────────────────────────────── */
.ground {
  position: relative;
  background: var(--night);
  color: var(--silver);
  border-top: 1px solid var(--line-soft);
  padding-bottom: 26px;
}

.ground__ruler {
  height: 10px;
  border-bottom: 1px solid var(--line-faint);
  background-image: repeating-linear-gradient(
    90deg,
    rgba(127, 224, 59, 0.5) 0 1px,
    transparent 1px 26px
  );
  opacity: 0.7;
}

.ground__inner {
  max-width: var(--width);
  margin: 0 auto;
  padding: clamp(34px, 5vw, 66px) var(--gutter) 0;
  display: grid;
  grid-template-columns: minmax(190px, 1fr) minmax(0, 2.1fr) minmax(230px, 1.2fr);
  gap: clamp(24px, 4vw, 52px);
}

.ground__lockup {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 12px;
  font-size: 21px;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--line);
}

.ground__mark {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  background: var(--neon);
  color: var(--night);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 800;
  line-height: 1;
}

.ground__coord {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--tactical);
}

.ground__nav {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 22px;
}

.ground__col-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--neon);
}

.ground__list li + li { margin-top: 9px; }

.ground__link {
  display: inline-flex;
  align-items: center;
  font-size: 14px;
  color: var(--silver);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.ground__link::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 1px;
  margin-right: 9px;
  background: var(--tactical);
  transition: width 0.2s var(--ease), background 0.2s var(--ease);
}

.ground__link:hover {
  color: var(--neon);
  border-bottom-color: var(--neon);
}

.ground__link:hover::before {
  width: 15px;
  background: var(--neon);
}

.ground__contact { font-size: 13px; }

.ground__line {
  display: grid;
  gap: 3px;
  padding: 9px 0;
  border-bottom: 1px dashed var(--line-faint);
}

.ground__line:last-child { border-bottom: 0; }

.ground__label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  color: var(--tactical);
}

.ground__value {
  color: var(--line);
  font-size: 13px;
  line-height: 1.7;
}

.ground__value--mono {
  font-family: var(--font-mono);
  letter-spacing: 0.03em;
  word-break: break-all;
}

.ground__legal {
  max-width: var(--width);
  margin: clamp(28px, 4vw, 46px) auto 0;
  padding: 16px var(--gutter) 0;
  border-top: 1px solid var(--line-faint);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--tactical);
}

/* ── 11. 通用工具与动效协议 ─────────────────────────── */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

#main-content { scroll-margin-top: 24px; }

[data-chapter] { scroll-margin-top: 24px; }

.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.32s var(--ease), transform 0.32s var(--ease);
  will-change: opacity, transform;
}

.has-js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ── 12. 响应式 ─────────────────────────────────────── */
@media (max-width: 1023px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .ground__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }

  .ground__contact { grid-column: 1 / -1; }
  .ground__nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 899px) {
  body { padding-left: 0; padding-top: var(--topbar-h); }

  .skip-link { left: 0; }

  #main-content { scroll-margin-top: calc(var(--topbar-h) + 16px); }
  [data-chapter] { scroll-margin-top: calc(var(--topbar-h) + 20px); }

  .rail {
    top: 0;
    left: 0;
    right: 0;
    bottom: auto;
    width: auto;
    height: var(--topbar-h);
    flex-direction: row;
    align-items: center;
    background: var(--night);
    border-right: 0;
    border-bottom: 1px solid var(--line-soft);
    overflow: visible;
  }

  .rail::before { display: none; }

  .rail__progress {
    top: auto;
    right: 0;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 2px;
    transform-origin: left center;
    transform: scaleX(var(--scroll-progress));
  }

  .rail__scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 65;
    background: rgba(6, 46, 16, 0.74);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.28s var(--ease);
  }

  .rail[data-open="true"] .rail__scrim {
    opacity: 1;
    pointer-events: auto;
  }

  .rail__topbar {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    width: 100%;
    height: var(--topbar-h);
    padding: 0 16px;
    border-bottom: 0;
    z-index: 80;
  }

  .rail__lockup {
    flex-direction: row;
    align-items: center;
    width: auto;
    padding: 0;
    gap: 9px;
  }

  .rail__mark { width: 26px; height: 26px; font-size: 13px; }

  .rail__word {
    writing-mode: horizontal-tb;
    font-size: 16px;
    letter-spacing: 0.08em;
  }

  .rail__toggle {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    padding: 8px 12px;
    border: 1px solid var(--line-soft);
    background: rgba(127, 224, 59, 0.08);
    color: var(--line);
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.1em;
    transition: background 0.2s var(--ease), color 0.2s var(--ease),
      border-color 0.2s var(--ease);
  }

  .rail__toggle-bars {
    position: relative;
    display: block;
    width: 16px;
    height: 10px;
  }

  .rail__toggle-bars::before,
  .rail__toggle-bars::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--neon);
  }

  .rail__toggle-bars::before {
    top: 0;
    box-shadow: 0 4px 0 var(--neon);
  }

  .rail__toggle-bars::after { bottom: 0; }

  .rail[data-open="true"] .rail__toggle {
    background: var(--neon);
    border-color: var(--neon);
    color: var(--night);
  }

  .rail[data-open="true"] .rail__toggle-bars::before,
  .rail[data-open="true"] .rail__toggle-bars::after {
    background: var(--night);
    box-shadow: none;
  }

  .rail__drawer {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    top: auto;
    z-index: 70;
    max-height: min(80vh, 580px);
    padding: 18px 16px 22px;
    background: var(--night);
    border-top: 2px solid var(--neon);
    transform: translateY(103%);
    transition: transform 0.32s var(--ease);
  }

  .rail[data-open="true"] .rail__drawer { transform: translateY(0); }

  .rail__nav { padding: 0 0 14px; }

  .rail__list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .rail__item + .rail__item { margin-top: 0; }

  .rail__link {
    flex-direction: row;
    align-items: center;
    gap: 10px;
    padding: 12px 12px;
    font-size: 14px;
    border-left: 0;
    border-bottom: 1px solid var(--line-faint);
    background: rgba(244, 247, 240, 0.03);
  }

  .rail__link[aria-current="page"] {
    border-left: 0;
    border-bottom-color: var(--neon);
  }

  .rail__idx { font-size: 10px; }

  .rail__chapters {
    padding: 12px 0 14px;
    border-top: 1px dashed var(--line-faint);
  }

  .rail__chapters-title { text-align: left; }

  .rail__chapter-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .rail__chapter {
    width: auto;
    display: inline-flex;
    align-items: baseline;
    gap: 7px;
    padding: 7px 11px;
    border: 1px solid var(--line-faint);
    text-align: left;
  }

  .rail__chapter-num { display: inline; }
  .rail__chapter-label { display: inline; font-size: 12px; }

  .rail__foot {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    padding: 14px 0 0;
  }

  .rail__slogan {
    writing-mode: horizontal-tb;
    font-size: 11px;
    letter-spacing: 0.16em;
    color: var(--tactical);
  }

  .rail__cta {
    writing-mode: horizontal-tb;
    flex: 1 1 auto;
    text-align: center;
    padding: 12px 18px;
  }

  .rail__to-top {
    width: 42px;
    height: 42px;
    font-size: 16px;
  }

  .rail__lang { display: none; }
}

@media (max-width: 719px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }

  .ground__inner { grid-template-columns: minmax(0, 1fr); }
  .ground__nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .ground__contact { grid-column: auto; }
  .ground__legal { flex-direction: column; }
}

/* ── 13. 减动效 ─────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .has-js [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .btn:hover { transform: none; }
  .rail__drawer { transition: none; }
}