/* ==========================================================================
   亿万28链接 · 星图索引站 · 共享样式表 /assets/site.css
   覆盖：reset / 变量 / 中文排版 / 头部 / 页脚 / 通用组件
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }

html {
  background-color: #05070f;
  color-scheme: dark;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 108px;
}

body, h1, h2, h3, h4, h5, h6, p, ul, ol, dl, dt, dd, figure, blockquote, pre { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { max-width: 100%; height: auto; }
button { font: inherit; color: inherit; background: none; border: 0; }
a { color: inherit; }

:root {
  /* 夜空底色分区 */
  --c-bg: #05070f;
  --c-panel: #0d1428;
  --c-panel-soft: rgba(13, 20, 40, 0.62);
  --c-ink: #f2f5fa;
  --c-ink-soft: #8f9ec4;
  --c-line: #1d2745;

  /* 三色功能强调 */
  --c-cyan: #3fe0cf;
  --c-orange: #ff6a2b;
  --c-purple: #a06bff;

  /* 档位色带 */
  --tier-1: #4fd8c8;
  --tier-2: #4aa8ff;
  --tier-3: #a06bff;
  --tier-4: #ff7a45;

  /* 保修温度阶 */
  --warm-cold: #6fb7ff;
  --warm-mid: #ffc14d;
  --warm-hot: #ff6a2b;

  /* 字体 */
  --font-display: "Archivo Narrow", "Oswald", "Roboto Condensed", "Source Han Sans HC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-base: "Inter", "Helvetica Neue", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", "Roboto Mono", Menlo, Consolas, "Noto Sans Mono", "Microsoft YaHei", monospace;

  /* 节奏 */
  --shell: 1280px;
  --gap: 24px;
  --bar-h: 78px;
  --radius-card: 24px;
  --ease: cubic-bezier(0.22, 0.7, 0.3, 1);
}

/* 星图底纹：斜向网格 + 星云辉光 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(1150px 640px at 84% -10%, rgba(160, 107, 255, 0.16), transparent 62%),
    radial-gradient(900px 520px at 4% 10%, rgba(63, 224, 207, 0.10), transparent 60%),
    radial-gradient(1000px 700px at 52% 116%, rgba(255, 106, 43, 0.08), transparent 64%),
    repeating-linear-gradient(16deg, rgba(143, 158, 196, 0.055) 0 1px, transparent 1px 118px),
    repeating-linear-gradient(-74deg, rgba(143, 158, 196, 0.038) 0 1px, transparent 1px 118px);
}

body {
  min-height: 100vh;
  font-family: var(--font-base);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-ink);
  background-color: transparent;
  overflow-x: hidden;
}

::selection { background: rgba(63, 224, 207, 0.28); color: #ffffff; }

:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ---------------------------------------------------------------
   排版基础
   --------------------------------------------------------------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 300;
  line-height: 1.05;
  letter-spacing: 0.01em;
}
h1 { font-size: clamp(2.75rem, 7vw, 5.5rem); }
h2 { font-size: clamp(1.75rem, 3.4vw, 2.75rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.7rem); }
h4 { font-size: 1.125rem; }

.mono, .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}
.text-cyan { color: var(--c-cyan); }
.text-orange { color: var(--c-orange); }
.text-purple { color: var(--c-purple); }

.label-index, .eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-ink-soft);
}

/* ---------------------------------------------------------------
   容器与网格
   --------------------------------------------------------------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: 24px;
}

.grid-12 { display: grid; grid-template-columns: repeat(12, 1fr); gap: var(--gap); }
.col-main { grid-column: span 8; }
.col-side { grid-column: span 4; }
.col-wide { grid-column: span 12; }
.col-offset-1 { grid-column-start: 2; }

.side-sticky { position: sticky; top: calc(var(--bar-h) + 24px); }

.section { padding-block: 96px; }
.section--tight { padding-block: 56px; }

.section-head { display: grid; gap: 18px; max-width: 62ch; margin-bottom: 48px; }
.section-head__index {
  font-family: var(--font-mono);
  font-size: clamp(3.5rem, 9vw, 7rem);
  font-weight: 500;
  line-height: 0.9;
  color: transparent;
  -webkit-text-stroke: 1px var(--c-line);
  letter-spacing: -0.03em;
}
.section-head__title { font-family: var(--font-display); font-weight: 200; font-size: clamp(1.8rem, 3.6vw, 2.9rem); line-height: 1.05; }
.section-head__note { font-size: 15px; color: var(--c-ink-soft); max-width: 58ch; }

.prose { max-width: 68ch; font-size: 17px; line-height: 1.75; color: var(--c-ink); }
.prose p + p, .prose p + ul, .prose ul + p { margin-top: 1.05em; }
.prose h2 { margin-top: 1.8em; font-size: clamp(1.5rem, 2.6vw, 2rem); }
.prose h3 { margin-top: 1.5em; font-size: 1.25rem; }
.prose strong { color: var(--c-cyan); font-weight: 500; }
.prose a { color: var(--c-cyan); text-decoration: underline; text-underline-offset: 3px; }
.prose ul { margin-top: 1em; display: grid; gap: 0.5em; }
.prose li { position: relative; padding-left: 22px; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.78em;
  width: 10px; height: 1px;
  background: var(--c-cyan);
}

/* 13° 斜向引导线 */
.slant-rule {
  position: relative;
  height: 128px;
  margin-block: 72px;
  overflow: hidden;
}
.slant-rule::before {
  content: "";
  position: absolute;
  left: -4%;
  top: 50%;
  width: 108%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(63, 224, 207, 0.42) 22%, rgba(29, 39, 69, 0.95) 78%, transparent);
  transform: rotate(-13deg);
}

/* ---------------------------------------------------------------
   按钮
   --------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 14px;
  letter-spacing: 0.04em;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease), box-shadow 0.18s var(--ease), transform 0.18s var(--ease);
}
.btn:active { transform: scale(0.985); }
.btn--primary { background: var(--c-cyan); border-color: var(--c-cyan); color: #04121a; }
.btn--primary:hover { box-shadow: 0 0 26px -6px rgba(63, 224, 207, 0.6); }
.btn--ghost { background: transparent; border-color: var(--c-line); color: var(--c-ink); }
.btn--ghost:hover { border-color: var(--c-cyan); color: var(--c-cyan); box-shadow: 0 0 0 1px rgba(63, 224, 207, 0.22), 0 0 20px -8px rgba(63, 224, 207, 0.55); }
.btn--quiet { padding: 8px 2px; color: var(--c-cyan); border: 0; }
.btn--quiet:hover { color: var(--c-ink); }

/* ---------------------------------------------------------------
   芯片 / 标签
   --------------------------------------------------------------- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  background: var(--c-panel-soft);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--c-ink-soft);
}
.chip--accent { color: var(--c-cyan); border-color: rgba(63, 224, 207, 0.38); background: rgba(63, 224, 207, 0.08); }
.chip--alert { color: var(--c-orange); border-color: rgba(255, 106, 43, 0.38); background: rgba(255, 106, 43, 0.08); }
.chip--version { color: var(--c-purple); border-color: rgba(160, 107, 255, 0.38); background: rgba(160, 107, 255, 0.08); }

/* ---------------------------------------------------------------
   卡片 / 数字模块
   --------------------------------------------------------------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}
.card {
  position: relative;
  padding: 26px 24px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-card);
  background: linear-gradient(158deg, rgba(13, 20, 40, 0.94), rgba(13, 20, 40, 0.52));
  transition: border-color 0.22s var(--ease), box-shadow 0.22s var(--ease), transform 0.22s var(--ease);
}
.card:hover {
  border-color: var(--c-cyan);
  box-shadow: 0 0 0 1px rgba(63, 224, 207, 0.18), 0 22px 48px -30px rgba(63, 224, 207, 0.7);
  transform: translateY(-3px);
}
.card--float { transform: translateY(-8px); }
.card--float:hover { transform: translateY(-11px); }
.card--band::before {
  content: "";
  position: absolute;
  left: 0; top: 24px; bottom: 24px;
  width: 2px;
  border-radius: 2px;
  background: var(--band-color, var(--c-cyan));
}
.card__label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--c-ink-soft);
}
.card__value {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  line-height: 1;
  color: var(--c-ink);
}
.card__note { margin-top: 12px; font-size: 13.5px; line-height: 1.65; color: var(--c-ink-soft); }

/* 价格四级色带 */
.band-price { display: flex; height: 6px; border-radius: 999px; overflow: hidden; }
.band-price__seg { flex: 1 1 25%; }
.band-price__seg--1 { background: var(--tier-1); }
.band-price__seg--2 { background: var(--tier-2); }
.band-price__seg--3 { background: var(--tier-3); }
.band-price__seg--4 { background: var(--tier-4); }

/* 保修温度阶 */
.temp-scale { display: flex; gap: 6px; align-items: center; }
.temp-scale__step { flex: 1; height: 6px; border-radius: 3px; }
.temp-scale__step--cold { background: var(--warm-cold); }
.temp-scale__step--warm { background: var(--warm-mid); }
.temp-scale__step--hot { background: var(--warm-hot); }

/* 仪表读数条 */
.stat-row {
  display: flex;
  flex-wrap: wrap;
  gap: 26px 44px;
  padding: 22px 0;
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
}
.stat { display: grid; gap: 6px; }
.stat__value { font-family: var(--font-mono); font-size: 30px; line-height: 1; color: var(--c-ink); }
.stat__unit { margin-left: 4px; font-family: var(--font-base); font-size: 13px; color: var(--c-ink-soft); }
.stat__label { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; color: var(--c-ink-soft); }

/* ---------------------------------------------------------------
   图片容器基础规则（页面阶段直接放 <img>）
   --------------------------------------------------------------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--c-line);
  border-radius: 26px;
  background: linear-gradient(150deg, #0a0f1e, #0d1428 55%, #070a14);
}
.media-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.85) brightness(0.78) contrast(1.05);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(115deg, rgba(63, 224, 207, 0.16), transparent 55%),
    linear-gradient(180deg, rgba(5, 7, 15, 0) 42%, rgba(5, 7, 15, 0.74));
}
.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--map { aspect-ratio: 21 / 9; }
.media-frame__caption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-ink-soft);
}

/* ---------------------------------------------------------------
   折叠面板
   --------------------------------------------------------------- */
.fold {
  border: 1px solid var(--c-line);
  border-radius: 20px;
  background: var(--c-panel-soft);
  overflow: hidden;
}
.fold + .fold { margin-top: 14px; }
.fold__summary {
  position: relative;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  padding: 20px 22px;
  font-size: 16.5px;
  color: var(--c-ink);
  cursor: pointer;
  list-style: none;
}
.fold__summary::-webkit-details-marker { display: none; }
.fold__summary::before {
  content: "";
  position: absolute;
  left: 0; top: 14px; bottom: 14px;
  width: 2px;
  border-radius: 2px;
  background: var(--c-cyan);
  opacity: 0;
  transition: opacity 0.2s var(--ease);
}
.fold[open] .fold__summary::before { opacity: 1; }
.fold[open] .fold__summary { color: var(--c-cyan); }
.fold__index { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em; color: var(--c-ink-soft); }
.fold__body { padding: 0 22px 22px; font-size: 15px; line-height: 1.75; color: var(--c-ink-soft); }

/* ---------------------------------------------------------------
   面包屑
   --------------------------------------------------------------- */
.breadcrumbs { padding-top: 24px; }
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
}
.breadcrumbs__item { display: inline-flex; align-items: center; gap: 10px; color: var(--c-ink-soft); }
.breadcrumbs__item + .breadcrumbs__item::before { content: "／"; color: var(--c-line); }
.breadcrumbs__link { color: var(--c-ink-soft); text-decoration: none; transition: color 0.18s var(--ease); }
.breadcrumbs__link:hover { color: var(--c-cyan); }
.breadcrumbs__current { color: var(--c-ink); }

/* ---------------------------------------------------------------
   显现动画
   --------------------------------------------------------------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}
html.js [data-reveal].is-visible { opacity: 1; transform: none; }

/* ==========================================================================
   头部 · 紧凑命令栏
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(5, 7, 15, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--c-line);
  color: var(--c-ink);
  transition: border-color 0.24s var(--ease);
}
.site-header[data-scrolled="true"] { --bar-h: 62px; border-color: rgba(63, 224, 207, 0.22); }

.scroll-progress {
  position: fixed;
  top: 0; left: 0;
  z-index: 70;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-purple));
  transform: scaleX(0);
  transform-origin: 0 50%;
}

.skip-link {
  position: absolute;
  left: 24px;
  top: -80px;
  z-index: 90;
  padding: 10px 16px;
  border-radius: 0 0 14px 14px;
  background: var(--c-cyan);
  color: #04121a;
  font-size: 14px;
  text-decoration: none;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 0; }

.command-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  width: 100%;
  max-width: var(--shell);
  min-height: var(--bar-h);
  margin-inline: auto;
  padding: 10px 24px;
  transition: min-height 0.24s var(--ease);
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--c-ink);
}
.brand-mark {
  position: relative;
  flex: none;
  width: 20px; height: 20px;
  border: 1.5px solid var(--c-cyan);
  border-radius: 50%;
  box-shadow: 0 0 0 4px rgba(63, 224, 207, 0.10);
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 5px;
  border-radius: 50%;
  background: var(--c-cyan);
}
.brand-name { font-size: 16px; font-weight: 600; letter-spacing: 0.06em; }
.brand-suffix {
  padding-left: 10px;
  border-left: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-ink-soft);
}

.primary-nav {
  display: flex;
  flex: 1 1 auto;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.primary-nav__list { display: flex; align-items: center; gap: 4px; counter-reset: navidx; }
.primary-nav__item { counter-increment: navidx; }
.primary-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 13px;
  border-radius: 999px;
  font-size: 14px;
  color: var(--c-ink-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.primary-nav__link::before {
  content: counter(navidx, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--c-line);
  transition: color 0.18s var(--ease);
}
.primary-nav__link:hover { color: var(--c-ink); background: rgba(29, 39, 69, 0.55); }
.primary-nav__link:hover::before { color: var(--c-ink-soft); }
.primary-nav__link[aria-current="page"] { color: var(--c-cyan); background: rgba(63, 224, 207, 0.08); }
.primary-nav__link[aria-current="page"]::before { color: var(--c-cyan); }
.primary-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  right: 10px; bottom: 4px;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 10px 1px rgba(63, 224, 207, 0.7);
}

.nav-status { display: flex; align-items: center; gap: 12px; }
.status-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid rgba(255, 106, 43, 0.36);
  border-radius: 999px;
  background: rgba(255, 106, 43, 0.08);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-orange);
  white-space: nowrap;
}
.status-chip__dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--c-orange);
  animation: pulse 3.2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(255, 106, 43, 0.55); }
  50% { box-shadow: 0 0 0 6px rgba(255, 106, 43, 0); }
}
.header-cta { white-space: nowrap; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 9px 14px;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  color: var(--c-ink);
  cursor: pointer;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.nav-toggle:hover { border-color: var(--c-cyan); color: var(--c-cyan); }
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px; height: 10px;
  border-top: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
}
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0; top: 50%;
  width: 12px; height: 1.5px;
  background: currentColor;
  transform: translateY(-50%);
}
.nav-toggle__label { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.14em; }

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer {
  position: relative;
  margin-top: 120px;
  border-top: 1px solid var(--c-line);
  background: linear-gradient(180deg, rgba(13, 20, 40, 0.18), rgba(13, 20, 40, 0.86));
  color: var(--c-ink-soft);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.3fr;
  gap: 40px 48px;
  padding-block: 72px 44px;
}

.footer-brand__name { font-family: var(--font-display); font-size: 22px; font-weight: 400; letter-spacing: 0.08em; color: var(--c-ink); }
.footer-brand__tag {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  color: var(--c-cyan);
}
.footer-brand__line { margin-top: 18px; max-width: 36ch; font-size: 14px; line-height: 1.75; }

.footer-index__title {
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--c-ink);
}
.footer-index__list { display: grid; gap: 10px; }
.footer-index__item { display: flex; }
.footer-index__link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 14.5px;
  color: var(--c-ink-soft);
  text-decoration: none;
  transition: color 0.18s var(--ease), gap 0.18s var(--ease);
}
.footer-index__link::before {
  content: "";
  flex: none;
  width: 14px; height: 1px;
  background: currentColor;
  opacity: 0.55;
}
.footer-index__link:hover { color: var(--c-cyan); gap: 14px; }

.footer-meta__list { display: grid; gap: 14px; }
.footer-meta__row { display: grid; grid-template-columns: 68px 1fr; gap: 12px; }
.footer-meta__label {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-ink-soft);
}
.footer-meta__value { font-size: 14px; line-height: 1.6; color: var(--c-ink); word-break: break-word; }
.footer-note {
  margin-top: 22px;
  padding-left: 14px;
  border-left: 2px solid rgba(255, 106, 43, 0.5);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-ink-soft);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 22px 34px;
  border-top: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}
.footer-region { color: var(--c-cyan); }
.footer-copyright { color: var(--c-ink-soft); }

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1080px) {
  .col-main { grid-column: span 7; }
  .col-side { grid-column: span 5; }
  .primary-nav__link { padding: 9px 10px; font-size: 13.5px; }
  .status-chip { display: none; }
}

@media (max-width: 980px) {
  :root { --bar-h: 68px; }

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

  .primary-nav {
    position: fixed;
    top: var(--bar-h);
    right: 0;
    bottom: 0;
    left: auto;
    z-index: 65;
    width: min(88vw, 340px);
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 26px;
    padding: 26px 22px 48px;
    background: var(--c-panel);
    border-left: 1px solid var(--c-line);
    overflow-y: auto;
    transform: translateX(102%);
    transition: transform 0.28s var(--ease);
  }
  .primary-nav[data-open="true"] { transform: translateX(0); }

  .primary-nav__list { flex-direction: column; align-items: stretch; gap: 2px; }
  .primary-nav__link {
    justify-content: flex-start;
    padding: 15px 12px;
    border-radius: 14px;
    border-bottom: 1px solid rgba(29, 39, 69, 0.75);
    font-size: 17px;
  }
  .primary-nav__link[aria-current="page"]::after { right: auto; left: 6px; top: 50%; bottom: auto; transform: translateY(-50%); }
  .primary-nav__link[aria-current="page"] { padding-left: 22px; }

  .nav-status { flex-direction: column; align-items: stretch; gap: 14px; }
  .nav-status .status-chip { display: inline-flex; justify-content: center; }
  .nav-status .btn { width: 100%; padding-block: 13px; }

  html.nav-open { overflow: hidden; }

  .grid-12 { grid-template-columns: 1fr; gap: 20px; }
  .col-main, .col-side, .col-wide, .col-offset-1 { grid-column: span 1 / -1; }
  .side-sticky { position: static; }

  .section { padding-block: 68px; }
  .section--tight { padding-block: 44px; }

  .footer-grid { grid-template-columns: 1fr 1fr; padding-block: 56px 36px; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  .shell { padding-inline: 18px; }
  .command-bar { padding: 8px 18px; gap: 12px; }
  .brand-suffix { display: none; }
  .brand-name { font-size: 15px; }
  .skip-link { left: 18px; }

  .footer-grid { grid-template-columns: 1fr; gap: 34px; }
  .footer-meta__row { grid-template-columns: 60px 1fr; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .slant-rule { height: 88px; margin-block: 48px; }
  .stat-row { gap: 20px 28px; }
}

/* ==========================================================================
   动效降级
   ========================================================================== */
@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;
  }
  html.js [data-reveal] { opacity: 1; transform: none; }
  .card--float { transform: none; }
  .card--float:hover { transform: none; }
  .btn:active { transform: none; }
}