/* ==========================================================
   竞博第一站 · 共享样式表 /assets/site.css
   深夜控制台外壳：竖向导航轨道 + 状态栏 + 分屏内容底座
   ========================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

body, h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { line-height: 1.24; font-weight: 700; }
[hidden] { display: none !important; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  --ink: #05070A;
  --ink-2: #0B0E13;
  --ink-3: #101A2B;
  --silver: #A7B0BD;
  --white: #E6EDF7;
  --cyan: #22D3EE;
  --gold: #F59E0B;
  --azure: #38BDF8;
  --lime: #A3E635;
  --magenta: #E879F9;

  --line: rgba(167, 176, 189, 0.16);
  --line-strong: rgba(167, 176, 189, 0.32);

  --radius-xl: 32px;
  --radius-l: 24px;
  --radius-m: 16px;
  --radius-s: 12px;
  --pill: 999px;

  --rail: 272px;
  --maxw: 1180px;

  --dur-1: 140ms;
  --dur-2: 220ms;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);

  --font-display: 'HarmonyOS Sans SC Condensed', 'Noto Sans SC', system-ui, sans-serif;
  --font-body: 'HarmonyOS Sans SC', 'Noto Sans SC', 'PingFang SC', system-ui, sans-serif;
  --font-serif: 'Source Han Serif SC', 'Songti SC', serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;

  color-scheme: dark;
}

/* ---------- 3. 页面基座 ---------- */
body {
  margin: 0;
  min-height: 100vh;
  color: var(--white);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.78;
  letter-spacing: 0.01em;
  background-color: var(--ink);
  background-image:
    repeating-linear-gradient(115deg, rgba(167, 176, 189, 0.032) 0 1px, transparent 1px 88px),
    radial-gradient(1100px 680px at 82% -12%, rgba(34, 211, 238, 0.11), transparent 62%),
    radial-gradient(880px 560px at -12% 18%, rgba(245, 158, 11, 0.07), transparent 64%);
  -webkit-font-smoothing: antialiased;
}

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(16, 26, 43, 0.88);
}

#main-content { display: block; }

.skip-link {
  position: fixed;
  top: -100px;
  left: 14px;
  z-index: 90;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 18px;
  border-radius: var(--pill);
  background: var(--cyan);
  color: #04121A;
  font-weight: 700;
  letter-spacing: 0.02em;
  transition: top var(--dur-1) var(--ease);
}

.skip-link:focus { top: 14px; }

/* ---------- 4. 四级色调 ---------- */
[data-tone] { --tone: var(--cyan); --tone-soft: rgba(34, 211, 238, 0.14); }
[data-tone="lime"] { --tone: var(--lime); --tone-soft: rgba(163, 230, 53, 0.14); }
[data-tone="gold"] { --tone: var(--gold); --tone-soft: rgba(245, 158, 11, 0.14); }
[data-tone="azure"] { --tone: var(--azure); --tone-soft: rgba(56, 189, 248, 0.14); }
[data-tone="magenta"] { --tone: var(--magenta); --tone-soft: rgba(232, 121, 249, 0.14); }
[data-tone="silver"] { --tone: var(--silver); --tone-soft: rgba(167, 176, 189, 0.14); }

/* ---------- 5. 文本工具 ---------- */
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; letter-spacing: 0.01em; }

.display {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 5rem);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.025em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
  opacity: 0.7;
}

.lede { font-size: 1.05rem; line-height: 1.85; color: #C9D4E4; max-width: 62ch; }

.editorial {
  font-family: var(--font-serif);
  font-size: 1.06rem;
  line-height: 1.95;
  color: #C9D4E4;
  border-left: 2px solid rgba(34, 211, 238, 0.5);
  padding-left: 18px;
}

.prose { max-width: 68ch; color: #C9D4E4; }
.prose p + p { margin-top: 1em; }
.prose h2 { margin: 2.2em 0 0.7em; font-size: 1.45rem; color: var(--white); }
.prose h3 { margin: 1.8em 0 0.6em; font-size: 1.14rem; color: var(--white); }
.prose a { color: var(--cyan); border-bottom: 1px solid rgba(34, 211, 238, 0.4); }
.prose ul, .prose ol { margin: 1em 0; padding-left: 1.2em; list-style: disc; }
.prose li + li { margin-top: 0.4em; }

/* ---------- 6. 舞台与栅格 ---------- */
.stage {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 32px 18px 76px;
}

.section { margin-bottom: 52px; }
.section:last-child { margin-bottom: 0; }

.section__head {
  display: grid;
  gap: 10px;
  margin-bottom: 22px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.section__title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  letter-spacing: -0.015em;
}

.section__desc { color: var(--silver); font-size: 0.94rem; max-width: 64ch; }

.grid { display: grid; gap: 16px; }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

.split { display: grid; gap: 26px; }

/* ---------- 7. 按钮与胶囊 ---------- */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 12px 20px;
  border-radius: var(--pill);
  border: 1px solid transparent;
  font-size: 0.94rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-align: center;
  transition: transform var(--dur-1) var(--ease), box-shadow var(--dur-2) var(--ease),
    border-color var(--dur-1) var(--ease), background var(--dur-1) var(--ease), color var(--dur-1) var(--ease);
}

.button--solid {
  background: linear-gradient(120deg, var(--cyan), var(--azure));
  color: #04121A;
  box-shadow: 0 14px 30px -18px rgba(34, 211, 238, 0.95);
}

.button--gold {
  background: linear-gradient(120deg, var(--gold), var(--magenta));
  color: #1A0A02;
}

.button--line {
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.035);
  color: var(--white);
}

.button--ghost { color: var(--cyan); border-color: transparent; }

.button:hover { transform: translateY(-2px); }
.button--solid:hover { box-shadow: 0 20px 38px -18px rgba(34, 211, 238, 1); }
.button--line:hover { border-color: var(--cyan); background: rgba(34, 211, 238, 0.1); }
.button--ghost:hover { color: var(--white); background: rgba(255, 255, 255, 0.05); }

.pill-row { display: flex; flex-wrap: wrap; gap: 8px; }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--pill);
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.03);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  color: var(--silver);
  white-space: nowrap;
}

.pill__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 8px currentColor;
}

.pill--lime { color: var(--lime); border-color: rgba(163, 230, 53, 0.38); }
.pill--cyan { color: var(--cyan); border-color: rgba(34, 211, 238, 0.38); }
.pill--azure { color: var(--azure); border-color: rgba(56, 189, 248, 0.38); }
.pill--gold { color: var(--gold); border-color: rgba(245, 158, 11, 0.38); }
.pill--magenta { color: var(--magenta); border-color: rgba(232, 121, 249, 0.38); }

/* ---------- 8. 卡片 ---------- */
.card {
  position: relative;
  display: grid;
  gap: 10px;
  padding: 20px;
  border-radius: var(--radius-l);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(16, 26, 43, 0.92), rgba(11, 14, 19, 0.94));
  overflow: hidden;
  transition: transform var(--dur-2) var(--ease), border-color var(--dur-2) var(--ease),
    box-shadow var(--dur-2) var(--ease), background var(--dur-2) var(--ease);
}

.card::after {
  content: "";
  position: absolute;
  inset: auto -30% -70% auto;
  width: 240px;
  height: 240px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--tone-soft, rgba(34, 211, 238, 0.14)), transparent 68%);
  opacity: 0;
  transition: opacity var(--dur-2) ease-out;
  pointer-events: none;
}

.card:hover {
  transform: translateY(-2px);
  border-color: rgba(34, 211, 238, 0.4);
  box-shadow: 0 22px 46px -30px rgba(34, 211, 238, 0.85);
}

.card[data-tone]:hover { border-color: var(--tone); }
.card:hover::after { opacity: 1; }

.card__title {
  font-family: var(--font-display);
  font-size: 1.12rem;
  letter-spacing: -0.01em;
  color: var(--white);
}

.card__desc { font-size: 0.92rem; color: var(--silver); line-height: 1.7; }

.card__meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--silver);
  text-transform: uppercase;
}

.card__tag {
  justify-self: start;
  padding: 3px 10px;
  border-radius: var(--pill);
  border: 1px solid var(--line-strong);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--tone, var(--cyan));
}

.card__link { justify-self: start; color: var(--cyan); font-size: 0.88rem; font-weight: 700; }

/* ---------- 9. 图片容器 ---------- */
.media {
  position: relative;
  border-radius: var(--radius-l);
  border: 1px solid var(--line);
  overflow: hidden;
  background:
    radial-gradient(120% 90% at 20% 0%, rgba(34, 211, 238, 0.16), transparent 60%),
    linear-gradient(150deg, var(--ink-3), var(--ink));
  aspect-ratio: 16 / 10;
}

.media__img { width: 100%; height: 100%; object-fit: cover; }

.media__caption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 14px 16px;
  font-size: 0.78rem;
  color: var(--silver);
  background: linear-gradient(transparent, rgba(5, 7, 10, 0.92));
}

.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--cut { clip-path: polygon(0 0, 100% 0, 100% 82%, 86% 100%, 0 100%); border-radius: var(--radius-l); }

/* ---------- 10. 仪表 ---------- */
.meter { display: flex; align-items: center; gap: 12px; }

.meter__track {
  flex: 1;
  height: 8px;
  border-radius: var(--pill);
  background: rgba(167, 176, 189, 0.16);
  overflow: hidden;
}

.meter__fill {
  display: block;
  height: 100%;
  width: var(--value, 60%);
  border-radius: var(--pill);
  background: linear-gradient(90deg, var(--cyan), var(--azure));
}

.ring {
  --deg: 240deg;
  width: 104px;
  aspect-ratio: 1;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: conic-gradient(var(--cyan) var(--deg), rgba(167, 176, 189, 0.16) 0);
}

.ring__inner {
  width: 76%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--ink-2);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--white);
}

/* ---------- 11. 时间线与折叠面板 ---------- */
.timeline {
  padding-left: 22px;
  border-left: 1px dashed rgba(167, 176, 189, 0.3);
}

.timeline__item { position: relative; padding: 0 0 24px 10px; }
.timeline__item:last-child { padding-bottom: 0; }

.timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 3px;
  transform: rotate(45deg);
  background: var(--ink);
  border: 2px solid var(--cyan);
}

.fold {
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background: rgba(16, 26, 43, 0.5);
  overflow: hidden;
}

.fold + .fold { margin-top: 10px; }

.fold__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  min-height: 48px;
  padding: 14px 18px;
  cursor: pointer;
  font-weight: 700;
  color: var(--white);
  list-style: none;
}

.fold__summary::-webkit-details-marker { display: none; }

.fold__summary::after {
  content: "＋";
  font-family: var(--font-mono);
  color: var(--cyan);
  flex: none;
}

.fold[open] .fold__summary::after { content: "－"; }

.fold__body { padding: 0 18px 18px; color: #C9D4E4; line-height: 1.85; font-size: 0.94rem; }

/* ---------- 12. 筛选标签 ---------- */
.filters { display: flex; flex-wrap: wrap; gap: 8px; }

.filter {
  min-height: 40px;
  padding: 8px 16px;
  border-radius: var(--pill);
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.035);
  color: var(--silver);
  font-size: 0.84rem;
  transition: color var(--dur-1) var(--ease), border-color var(--dur-1) var(--ease),
    background var(--dur-1) var(--ease);
}

.filter:hover { color: var(--white); border-color: var(--cyan); }

.filter[aria-pressed="true"] {
  color: #04121A;
  background: linear-gradient(120deg, var(--cyan), var(--azure));
  border-color: transparent;
  font-weight: 700;
}

/* ---------- 13. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  font-size: 0.78rem;
  color: var(--silver);
}

.breadcrumbs a { border-bottom: 1px solid transparent; transition: color var(--dur-1) var(--ease); }
.breadcrumbs a:hover { color: var(--cyan); border-color: currentColor; }
.breadcrumbs__sep { opacity: 0.5; }
.breadcrumbs [aria-current="page"] { color: var(--white); }

/* ---------- 14. 头部外壳 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  display: grid;
  gap: 10px;
  padding: 10px 16px 12px;
  background: linear-gradient(180deg, rgba(11, 14, 19, 0.96), rgba(5, 7, 10, 0.92));
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(167, 176, 189, 0.14);
  overflow: hidden;
}

.scroll-meter__fill {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--magenta));
  transform-origin: 0 50%;
  transform: scaleX(var(--p, 0));
}

.statusbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 12px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--silver);
}

.statusbar__seg { display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; }
.statusbar__live { color: var(--lime); }
.statusbar__mono { font-variant-numeric: tabular-nums; }

.statusbar__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 10px rgba(163, 230, 53, 0.8);
}

.site-header__identity {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  border-radius: var(--radius-m);
}

.brand__mark {
  position: relative;
  flex: none;
  width: 34px;
  height: 34px;
  border-radius: 11px;
  background: linear-gradient(135deg, var(--cyan), var(--azure) 46%, var(--magenta));
  box-shadow: inset 0 0 0 1px rgba(230, 237, 247, 0.2), 0 10px 24px -12px rgba(34, 211, 238, 0.95);
}

.brand__mark::after {
  content: "";
  position: absolute;
  inset: 9px;
  background: var(--ink);
  clip-path: polygon(0 0, 100% 0, 100% 62%, 62% 100%, 0 100%);
}

.brand__text { display: flex; flex-direction: column; line-height: 1.16; }

.brand__name {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.brand__tag { font-size: 0.7rem; letter-spacing: 0.06em; color: var(--silver); }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  min-width: 44px;
  padding: 8px 14px;
  border-radius: var(--pill);
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.04);
  color: var(--white);
  font-size: 0.85rem;
  transition: border-color var(--dur-1) var(--ease), background var(--dur-1) var(--ease);
}

.nav-toggle:hover { border-color: var(--cyan); background: rgba(34, 211, 238, 0.1); }
.nav-toggle__text { letter-spacing: 0.06em; }

.nav-toggle__bars { position: relative; flex: none; width: 16px; height: 12px; }

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur-2) var(--ease), top var(--dur-2) var(--ease);
}

.nav-toggle__bars::before { top: 2px; }
.nav-toggle__bars::after { top: 8px; }

.site-header[data-open] .nav-toggle__bars::before { top: 5px; transform: rotate(45deg); }
.site-header[data-open] .nav-toggle__bars::after { top: 5px; transform: rotate(-45deg); }

.site-header__note { display: none; }
.site-header__meta { display: none; }

.site-nav { display: none; }

.site-header[data-open] .site-nav {
  display: block;
  padding-top: 4px;
  border-top: 1px dashed var(--line);
  animation: navIn var(--dur-2) var(--ease) both;
}

@keyframes navIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: none; }
}

.site-nav__list { display: grid; gap: 4px; }

.site-nav__link {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 48px;
  padding: 10px 14px;
  border-radius: var(--radius-m);
  border: 1px solid transparent;
  color: var(--silver);
  font-size: 0.95rem;
  transition: color var(--dur-1) var(--ease), background var(--dur-1) var(--ease),
    border-color var(--dur-1) var(--ease);
}

.site-nav__link::before {
  content: "";
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  transform: rotate(45deg);
  background: var(--tone, var(--cyan));
  opacity: 0.55;
  transition: opacity var(--dur-1) var(--ease), box-shadow var(--dur-2) ease-out;
}

.site-nav__link:hover {
  color: var(--white);
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--line);
}

.site-nav__link:hover::before { opacity: 1; box-shadow: 0 0 14px var(--tone, var(--cyan)); }

.site-nav__link[aria-current="page"] {
  color: var(--white);
  font-weight: 700;
  background: var(--tone-soft, rgba(34, 211, 238, 0.14));
  border-color: var(--tone, var(--cyan));
}

.site-nav__link[aria-current="page"]::before { opacity: 1; box-shadow: 0 0 14px var(--tone, var(--cyan)); }

.site-header__actions { display: none; flex-direction: column; gap: 8px; }
.site-header[data-open] .site-header__actions { display: flex; }

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 40px;
  padding: 40px 18px 28px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, var(--ink-2), var(--ink));
}

.site-footer__inner {
  max-width: var(--maxw);
  margin-inline: auto;
  display: grid;
  gap: 30px;
}

.site-footer__brand { display: grid; gap: 12px; justify-items: start; }
.brand--footer .brand__name { font-size: 1.12rem; }

.site-footer__line {
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.85;
  color: #C9D4E4;
  max-width: 30ch;
}

.footer-nav { display: grid; gap: 26px; }

.footer-nav__title {
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-nav__list { display: grid; gap: 2px; }

.footer-nav__link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 6px 0;
  color: var(--silver);
  font-size: 0.92rem;
  transition: color var(--dur-1) var(--ease), transform var(--dur-1) var(--ease);
}

.footer-nav__link:hover { color: var(--white); transform: translateX(3px); }

.footer-nav__list--plain {
  gap: 6px;
  color: var(--silver);
  font-size: 0.88rem;
  line-height: 1.85;
}

.footer-nav__list--plain li { max-width: 40ch; }
.footer-nav__list--plain .mono { color: #C9D4E4; word-break: break-all; }

.site-footer__base {
  max-width: var(--maxw);
  margin: 30px auto 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 6px;
  font-size: 0.76rem;
  color: var(--silver);
}

.site-footer__legal { font-family: var(--font-mono); letter-spacing: 0.02em; }
.site-footer__note { color: var(--silver); }

/* ---------- 16. 显现动效 ---------- */
[data-reveal] {
  transition: opacity 340ms ease-out, transform 340ms var(--ease);
}

.js-ready [data-reveal] { opacity: 0; transform: translateY(14px); }
.js-ready [data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 17. 平板与桌面 ---------- */
@media (min-width: 700px) {
  .stage { padding: 40px 28px 96px; }
  .site-header { padding: 12px 24px 14px; }
  .site-footer { padding: 48px 28px 30px; }
}

@media (min-width: 900px) {
  .footer-nav { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 32px; }

  .site-footer__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.7fr);
    gap: 48px;
    align-items: start;
  }

  .site-footer__base {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
  }
}

@media (min-width: 1024px) {
  .split { grid-template-columns: minmax(0, 0.86fr) minmax(0, 1.14fr); gap: 40px; align-items: start; }
  .split--reverse { grid-template-columns: minmax(0, 1.14fr) minmax(0, 0.86fr); }
  .split--reverse > :first-child { order: 2; }
}

@media (min-width: 1080px) {
  html { scroll-padding-top: 24px; }

  body { padding-left: var(--rail); }

  .site-header {
    position: fixed;
    inset: 0 auto 0 0;
    width: var(--rail);
    height: 100vh;
    height: 100dvh;
    display: flex;
    flex-direction: column;
    gap: 18px;
    padding: 22px 18px 20px;
    background: linear-gradient(180deg, #0B0E13 0%, #05070A 56%, #0B0E13 100%);
    border-bottom: 0;
    border-right: 1px solid var(--line);
    backdrop-filter: none;
    overflow-y: auto;
    overscroll-behavior: contain;
  }

  .scroll-meter { top: 0; right: 0; bottom: auto; left: auto; width: 3px; height: 100%; }

  .scroll-meter__fill {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, var(--cyan), var(--magenta));
    transform-origin: 50% 0;
    transform: scaleY(var(--p, 0));
  }

  .statusbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 5px;
    padding-bottom: 16px;
    border-bottom: 1px dashed var(--line);
  }

  .site-header__identity { flex-direction: column; align-items: flex-start; gap: 12px; }
  .nav-toggle { display: none; }

  .site-header__note {
    display: block;
    font-size: 0.82rem;
    line-height: 1.75;
    color: var(--silver);
  }

  .site-header__meta {
    display: block;
    margin-top: auto;
    padding-top: 16px;
    border-top: 1px dashed var(--line);
    font-size: 0.72rem;
    letter-spacing: 0.04em;
    color: var(--silver);
  }

  .site-nav { display: block; }
  .site-header[data-open] .site-nav { padding-top: 0; border-top: 0; animation: none; }

  .site-nav__list { gap: 2px; }
  .site-nav__link { min-height: 44px; padding: 8px 12px; }

  .site-header__actions { display: flex; flex-direction: column; gap: 8px; }
  .site-header__actions .button { min-height: 44px; padding: 10px 16px; font-size: 0.88rem; }

  .stage { padding: 52px 40px 110px; }
  .site-footer { margin-top: 60px; padding: 60px 40px 34px; }
}

/* ---------- 18. 无障碍与降级 ---------- */
@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-ready [data-reveal] { opacity: 1; transform: none; }
  .card:hover, .button:hover, .footer-nav__link:hover { transform: none; }
}