/* ============================================================
   乐动体育平台 CN — 共享样式 /assets/site.css
   竞技暗房 · 数据仪表盘 · 侧边轨道导航
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root {
  --ink-950: #101414;
  --ink-900: #0B1F1A;
  --panel: #123B35;
  --line: #1E5A4A;
  --lime: #C6FF4A;
  --amber: #FFB347;
  --rose: #FF3D7F;
  --text: #E8F0EA;
  --muted: #8FA69B;
  --paper: #F5F7F2;

  --bg: var(--ink-900);
  --border: rgba(30, 90, 74, 0.78);
  --border-soft: rgba(30, 90, 74, 0.42);

  --rail-w: 248px;
  --bar-h: 60px;
  --gutter: clamp(1rem, 3.4vw, 3rem);
  --maxw: 1240px;

  --font-display: "Archivo Narrow", "Arial Narrow", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "Microsoft YaHei", sans-serif;

  --step--1: clamp(0.75rem, 0.72rem + 0.12vw, 0.8125rem);
  --step-0: clamp(0.9375rem, 0.9rem + 0.18vw, 1rem);
  --step-1: clamp(1.0625rem, 1rem + 0.3vw, 1.25rem);
  --step-2: clamp(1.375rem, 1.15rem + 0.9vw, 1.875rem);
  --step-3: clamp(1.875rem, 1.35rem + 2.2vw, 3rem);
  --step-4: clamp(2.5rem, 1.5rem + 4vw, 4.5rem);
  --step-5: clamp(3.25rem, 1.6rem + 6.5vw, 7rem);

  --shadow-plate: 0 1px 0 rgba(232, 240, 234, 0.04), 0 18px 40px -28px rgba(0, 0, 0, 0.92);
}

/* ---------- 2. 基础重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--bar-h) + 20px);
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--step-0);
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.012em;
  padding-left: var(--rail-w);
  padding-right: var(--gutter);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* 背景：棋牌格纹 + 顶部光晕，只做氛围不抢内容 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(180deg, rgba(18, 59, 53, 0.55) 0%, transparent 38%),
    linear-gradient(90deg, rgba(30, 90, 74, 0.16) 1px, transparent 1px),
    linear-gradient(180deg, rgba(30, 90, 74, 0.16) 1px, transparent 1px);
  background-size: 100% 100%, 72px 72px, 72px 72px;
  opacity: 0.7;
}

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

h1, h2, h3, h4 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--paper);
  overflow-wrap: break-word;
}

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--lime); text-decoration: none; }
a:hover { color: var(--amber); }

ul, ol { margin: 0; padding: 0; }

button { font: inherit; color: inherit; }

figure { margin: 0; }

::selection { background: var(--lime); color: #07130E; }

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

main { display: block; position: relative; z-index: 1; }

/* ---------- 3. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 0.6rem 1rem;
  background: var(--lime);
  color: #07130E;
  font-family: var(--font-mono);
  font-size: var(--step--1);
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  border-radius: 2px;
  transform: translateY(-200%);
  transition: transform 0.2s ease;
}
.skip-link:focus-visible { transform: translateY(0); color: #07130E; }

/* ---------- 4. 侧边轨道页头 ---------- */
.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 80;
  display: flex;
  width: var(--rail-w);
  background: var(--ink-950);
  border-right: 1px solid var(--border);
}

.rail::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  right: -1px;
  width: 1px;
  background: linear-gradient(180deg, var(--lime) 0%, transparent 42%, transparent 62%, var(--rose) 100%);
  opacity: 0.42;
  pointer-events: none;
}

.rail__inner {
  display: flex;
  flex-direction: column;
  width: 100%;
  gap: 1.5rem;
  padding: clamp(1.25rem, 3vh, 2rem) clamp(1rem, 2.2vw, 1.5rem);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}
.rail__inner::-webkit-scrollbar { width: 6px; }
.rail__inner::-webkit-scrollbar-thumb { background: var(--line); border-radius: 3px; }

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: inherit;
  text-decoration: none;
}
.brand:hover { color: inherit; }
.brand__mark {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  color: var(--lime);
}
.brand__mark svg { width: 100%; height: 100%; }
.brand__text { min-width: 0; }
.brand__name {
  display: block;
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1.2;
  color: var(--paper);
}
.brand__tag {
  display: block;
  margin-top: 0.28rem;
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  line-height: 1.4;
  color: var(--muted);
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.55rem;
  padding: 0.5rem 0.7rem;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.nav-toggle:hover { color: var(--lime); border-color: var(--line); }
.nav-toggle__bars {
  display: block;
  width: 16px;
  height: 2px;
  border-radius: 1px;
  background: currentColor;
  box-shadow: 0 -5px 0 currentColor, 0 5px 0 currentColor;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

/* 导航 */
.nav { margin-top: 0.2rem; }
.nav__list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  list-style: none;
}
.nav__item { min-width: 0; }
.nav__link {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.55rem 0.6rem;
  min-height: 40px;
  color: var(--muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  border-radius: 2px;
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}
.nav__idx {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0;
  color: var(--line);
  transition: color 0.18s ease;
}
.nav__label {
  font-family: var(--font-display);
  letter-spacing: 0.14em;
}
.nav__link:hover {
  color: var(--text);
  background: rgba(30, 90, 74, 0.22);
  border-left-color: var(--line);
}
.nav__link:hover .nav__idx { color: var(--muted); }
.nav__link[aria-current="page"] {
  color: var(--lime);
  background: rgba(198, 255, 74, 0.07);
  border-left-color: var(--lime);
}
.nav__link[aria-current="page"] .nav__idx { color: var(--lime); }

/* 轨道底部信息 */
.rail__meta {
  margin-top: auto;
  padding-top: 1.25rem;
  border-top: 1px dashed var(--border-soft);
  display: flex;
  flex-direction: column;
  gap: 0.28rem;
}
.rail__eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--muted);
}
.rail__tel {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: 0.02em;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}
.rail__hours {
  margin: 0;
  font-size: 0.75rem;
  color: var(--muted);
}
.rail__status {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin: 0.55rem 0 0;
  font-size: 0.6875rem;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.rail__dot {
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 0 3px rgba(198, 255, 74, 0.14);
  animation: railPulse 2.4s ease-in-out infinite;
}
@keyframes railPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

/* 返回顶部 */
.to-top {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  width: 100%;
  margin-top: 0.75rem;
  padding: 0.6rem 0.5rem;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}
.to-top:hover {
  color: var(--lime);
  border-color: var(--lime);
  background: rgba(198, 255, 74, 0.06);
}
.to-top__arrow { font-size: 0.875rem; line-height: 1; }
.to-top__text { letter-spacing: 0.18em; }

/* 阅读进度 */
.scroll-progress {
  position: fixed;
  left: var(--rail-w);
  right: 0;
  bottom: 0;
  height: 2px;
  z-index: 90;
  pointer-events: none;
  background: rgba(30, 90, 74, 0.28);
}
.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--lime) 0%, var(--amber) 68%, var(--rose) 100%);
  transition: width 0.08s linear;
}

/* ---------- 5. 页脚 ---------- */
.foot {
  position: relative;
  z-index: 1;
  margin-top: clamp(3rem, 8vw, 6rem);
  padding: clamp(2.5rem, 6vw, 4.5rem) var(--gutter) 1.5rem;
  background: var(--ink-950);
  border-top: 1px solid var(--border);
}
.foot::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--lime) 0%, var(--amber) 45%, var(--rose) 100%);
  opacity: 0.55;
}

.foot__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3rem);
  max-width: var(--maxw);
  margin-inline: auto;
}

.foot__brand { min-width: 0; }
.foot__name {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-size: var(--step-2);
  font-weight: 500;
  letter-spacing: 0.05em;
  color: var(--paper);
}
.foot__tag {
  margin: 0 0 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--lime);
}
.foot__note {
  max-width: 34ch;
  margin: 0 0 1rem;
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--muted);
}
.foot__icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--line);
}

.foot__col { min-width: 0; }
.foot__head {
  margin: 0 0 0.85rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px dashed var(--border-soft);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}
.foot__list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  list-style: none;
}
.foot__list a {
  display: inline-block;
  padding: 0.1rem 0;
  color: var(--text);
  font-size: 0.875rem;
  letter-spacing: 0.04em;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.foot__list a:hover { color: var(--lime); border-bottom-color: var(--lime); }
.foot__list a[aria-current="page"] { color: var(--lime); }

.foot__line {
  margin: 0 0 0.7rem;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--text);
}
.foot__key {
  display: block;
  margin-bottom: 0.15rem;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--line);
}

.foot__bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  max-width: var(--maxw);
  margin: clamp(2rem, 5vw, 3rem) auto 0;
  padding-top: 1rem;
  border-top: 1px solid var(--border-soft);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.foot__copy, .foot__icpbar { margin: 0; }

/* ---------- 6. 布局工具 ---------- */
.wrap {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
}

.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1rem, 2.4vw, 1.75rem);
  align-items: start;
}

.prose {
  max-width: 62ch;
  color: var(--text);
}
.prose > * + * { margin-top: 1.05em; }
.prose h2 {
  font-size: var(--step-2);
  letter-spacing: 0.03em;
  margin-top: 1.8em;
}
.prose h3 {
  font-size: var(--step-1);
  letter-spacing: 0.04em;
  margin-top: 1.5em;
  color: var(--lime);
}
.prose ul, .prose ol {
  padding-left: 1.15em;
  list-style-position: outside;
}
.prose li { margin-bottom: 0.45em; }
.prose strong { color: var(--paper); font-weight: 600; }

/* ---------- 7. 版块与标题 ---------- */
.section { position: relative; }
.section__eyebrow {
  display: block;
  margin-bottom: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--amber);
}
.section__title {
  margin: 0 0 0.8rem;
  font-size: var(--step-3);
  font-weight: 400;
  letter-spacing: 0.015em;
  line-height: 1.06;
  color: var(--paper);
  max-width: 24ch;
}
.lede {
  max-width: 46ch;
  font-size: var(--step-1);
  line-height: 1.65;
  color: var(--text);
}

/* 面包屑 */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.4rem;
  margin: 0 0 1.5rem;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.crumbs a { color: var(--muted); }
.crumbs a:hover { color: var(--lime); }
.crumbs li + li::before {
  content: "/";
  margin-right: 0.45rem;
  color: var(--line);
}
.crumbs [aria-current="page"] { color: var(--lime); }

/* ---------- 8. 数据面板 ---------- */
.panel {
  position: relative;
  min-width: 0;
  padding: clamp(1rem, 2.2vw, 1.5rem);
  background: linear-gradient(180deg, rgba(18, 59, 53, 0.72) 0%, rgba(11, 31, 26, 0.94) 100%);
  border: 1px solid var(--border);
  border-radius: 3px;
  box-shadow: var(--shadow-plate);
}
.panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 22px;
  height: 22px;
  border-top: 2px solid var(--lime);
  border-left: 2px solid var(--lime);
  border-top-left-radius: 3px;
  opacity: 0.65;
  pointer-events: none;
}
.panel__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px dashed var(--border-soft);
}
.panel__title {
  margin: 0;
  font-size: var(--step-1);
  font-weight: 500;
  letter-spacing: 0.05em;
  color: var(--paper);
}
.panel__meta {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  min-width: 0;
}
.stat__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--step-3);
  line-height: 1;
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}
.stat__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}
.stat--lime .stat__value { color: var(--lime); }
.stat--rose .stat__value { color: var(--rose); }

/* ---------- 9. 标签 / 按钮 / 纸张 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35em;
  padding: 0.28em 0.62em;
  background: rgba(11, 31, 26, 0.65);
  border: 1px solid var(--border);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}
.tag--lime { color: var(--lime); border-color: rgba(198, 255, 74, 0.5); }
.tag--amber { color: var(--amber); border-color: rgba(255, 179, 71, 0.5); }
.tag--rose { color: var(--rose); border-color: rgba(255, 61, 127, 0.5); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 1.35rem;
  background: var(--lime);
  border: 1px solid var(--lime);
  border-radius: 2px;
  color: #07130E;
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}
.btn:hover {
  background: transparent;
  color: var(--lime);
  transform: translateY(-1px);
}
.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn--ghost:hover {
  color: var(--lime);
  border-color: var(--lime);
  background: rgba(198, 255, 74, 0.06);
}

.plate {
  position: relative;
  isolation: isolate;
  padding: clamp(1rem, 2.5vw, 1.5rem);
  background: var(--paper);
  color: #0B1F1A;
  border-radius: 2px;
  box-shadow: var(--shadow-plate);
}
.plate::before {
  content: "";
  position: absolute;
  inset: 10px -10px -10px 10px;
  border: 1px solid var(--border);
  border-radius: 2px;
  z-index: -1;
}
.plate h2, .plate h3, .plate h4 { color: #0B1F1A; }
.plate a { color: #1E5A4A; }
.plate a:hover { color: #B3205A; }
.plate .tag {
  background: rgba(11, 31, 26, 0.06);
  color: #1E5A4A;
  border-color: rgba(30, 90, 74, 0.4);
}

/* ---------- 10. 响应式图片容器 ---------- */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  background: linear-gradient(135deg, #123B35 0%, #0B1F1A 100%);
  border: 1px solid var(--border);
  border-radius: 2px;
}
.img-frame > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  box-shadow: inset 0 0 0 1px rgba(198, 255, 74, 0.07);
  pointer-events: none;
}
.img-frame--16x9 { aspect-ratio: 16 / 9; }
.img-frame--4x3 { aspect-ratio: 4 / 3; }
.img-frame--3x2 { aspect-ratio: 3 / 2; }
.img-frame--1x1 { aspect-ratio: 1 / 1; }
.img-frame--tall { aspect-ratio: 3 / 4; }

.img-frame__ph {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--line);
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  background-image:
    linear-gradient(45deg, rgba(30, 90, 74, 0.2) 25%, transparent 25%, transparent 75%, rgba(30, 90, 74, 0.2) 75%),
    linear-gradient(45deg, rgba(30, 90, 74, 0.2) 25%, transparent 25%, transparent 75%, rgba(30, 90, 74, 0.2) 75%);
  background-size: 28px 28px;
  background-position: 0 0, 14px 14px;
}
.img-frame__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 0.55rem 0.75rem;
  background: linear-gradient(0deg, rgba(11, 31, 26, 0.94) 0%, transparent 100%);
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ---------- 11. 动效协议 ---------- */
[data-reveal] { opacity: 1; transform: none; }
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
}
.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
  transition: opacity 0.5s ease, transform 0.5s ease;
}

[data-toc-link] { transition: color 0.2s ease; }
[data-toc-link][aria-current] { color: var(--lime); }

/* ---------- 12. 断点 ---------- */
@media (min-width: 700px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1024px) {
  html { scroll-padding-top: 24px; }
  .foot__grid { grid-template-columns: 1.5fr 1fr 1fr 1.4fr; }
}

@media (min-width: 1080px) {
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 1023px) {
  body {
    padding-left: 0;
    padding-right: 0;
    padding-top: var(--bar-h);
  }

  .rail {
    top: 0;
    right: 0;
    bottom: auto;
    left: 0;
    width: auto;
    height: var(--bar-h);
    align-items: center;
    padding-inline: var(--gutter);
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }
  .rail::after { display: none; }

  .rail__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    height: 100%;
    padding: 0;
    overflow: visible;
  }

  .brand { gap: 0.6rem; }
  .brand__mark { width: 28px; height: 28px; }
  .brand__name { font-size: 0.875rem; }
  .brand__tag { display: none; }

  .nav-toggle { display: inline-flex; }

  .nav {
    position: fixed;
    top: var(--bar-h);
    left: 0;
    right: 0;
    z-index: 78;
    margin: 0;
    max-height: calc(100vh - var(--bar-h));
    overflow-y: auto;
    padding: 1rem var(--gutter) 1.6rem;
    background: var(--ink-950);
    border-bottom: 1px solid var(--border);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s ease;
  }
  .nav__list { gap: 0.25rem; }
  .nav__link {
    padding: 0.9rem 0.75rem;
    min-height: 48px;
    font-size: 1rem;
  }
  .nav__idx { font-size: 0.6875rem; }

  .rail[data-open] .nav {
    opacity: 1;
    visibility: visible;
    transform: none;
  }
  .rail[data-open] .nav-toggle {
    color: var(--lime);
    border-color: var(--lime);
  }
  .rail[data-open] .nav-toggle__bars {
    transform: scaleX(0.6);
    box-shadow: 0 -5px 0 currentColor, 0 5px 0 currentColor;
  }

  .rail__meta { display: none; }

  .to-top {
    position: fixed;
    right: 14px;
    bottom: 18px;
    z-index: 75;
    width: auto;
    margin: 0;
    padding: 0.7rem 0.8rem;
    background: var(--ink-950);
    box-shadow: 0 12px 26px -14px rgba(0, 0, 0, 0.95);
  }
  .to-top__text { display: none; }
  .to-top__arrow { font-size: 1rem; }

  .scroll-progress { left: 0; }

  .foot { margin-top: clamp(2.5rem, 10vw, 4rem); }
}

@media (max-width: 699px) {
  .crumbs { font-size: 0.625rem; }
  .section__title { max-width: none; }
}

/* ---------- 13. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .js [data-reveal] {
    opacity: 1;
    transform: none;
  }
  .scroll-progress__bar { transition: none; }
}