/* =========================================================
   纯净赛场 · 共享样式表 /assets/site.css
   技术蓝图网格 + 近单色冰蓝体系 + 荧光绿/暖橙数据高亮
   ========================================================= */

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

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

body { margin: 0; }

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

h1, h2, h3, h4, p, figure, ul, ol, blockquote { margin: 0; }

ul, ol { padding: 0; list-style: none; }

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

a { color: inherit; text-decoration: none; }

hr { height: 1px; margin: 0; border: 0; background: var(--grid); }

/* ---------- 2. 变量 ---------- */
:root {
  --deep: #06121D;
  --grid: #102A3C;
  --ice: #6FD3F2;
  --glacier: #BFE9F8;
  --snow: #F2FAFE;
  --slate: #8FA6B4;
  --slate-dim: #63808F;
  --neon: #4CE0A0;
  --amber: #FF9C4A;
  --mist: #EEF6FB;
  --ink: #0A1A26;
  --edge: #1D4058;

  --rail-w: 96px;
  --maxw: 1280px;
  --gut: 24px;
  --r-xl: 28px;
  --r-lg: 22px;
  --r-md: 16px;
  --r-pill: 999px;

  --mono: 'JetBrains Mono', 'Roboto Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Noto Sans SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.85;
  color: var(--snow);
  background-color: var(--deep);
  background-image:
    radial-gradient(900px 520px at 18% -8%, rgba(111, 211, 242, 0.10), transparent 68%),
    radial-gradient(700px 420px at 92% 12%, rgba(76, 224, 160, 0.06), transparent 70%),
    linear-gradient(to right, rgba(16, 42, 60, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(16, 42, 60, 0.55) 1px, transparent 1px);
  background-size: auto, auto, 88px 88px, 88px 88px;
  background-attachment: scroll;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.15;
}

h1 { font-size: clamp(32px, 5vw, 46px); }
h2 { font-size: clamp(26px, 3.6vw, 38px); }
h3 { font-size: 20px; line-height: 1.4; }

p { line-height: 1.85; }

::selection { background: rgba(111, 211, 242, 0.32); color: var(--snow); }

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

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: -120px;
  left: 14px;
  z-index: 200;
  padding: 10px 20px;
  border-radius: 0 0 var(--r-md) var(--r-md);
  background: var(--ice);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  transition: top 0.2s ease;
}
.skip-link:focus { top: 0; }

/* ---------- 5. 布局 ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gut);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gut);
}

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-12 { grid-column: span 12; }

/* ---------- 6. 分区节奏 ---------- */
.zone {
  position: relative;
  padding: 64px 0;
}
.zone--tight { padding: 40px 0; }

.zone--panel {
  background: linear-gradient(180deg, rgba(16, 42, 60, 0.42), rgba(6, 18, 29, 0) 78%);
}

.zone--mist {
  background: var(--mist);
  color: var(--ink);
}

.zone--mist .sec-title,
.zone--mist h1,
.zone--mist h2,
.zone--mist h3 { color: var(--ink); }

.zone--mist .sec-lead,
.zone--mist .u-slate,
.zone--mist .stat__label,
.zone--mist .stat__unit,
.zone--mist .media__caption,
.zone--mist .crumbs { color: #5B7385; }

.zone--mist .prose { color: #12293A; }
.zone--mist .prose a { color: #0A6C8F; }

.zone--mist .card {
  background: #FFFFFF;
  border-color: rgba(10, 26, 38, 0.12);
  color: var(--ink);
}
.zone--mist .card:hover { border-color: rgba(10, 108, 143, 0.5); }

.zone--mist .chip {
  border-color: rgba(10, 26, 38, 0.16);
  background: rgba(10, 26, 38, 0.03);
  color: #3A5468;
}
.zone--mist .chip:hover { border-color: var(--ink); color: var(--ink); }
.zone--mist .chip[aria-pressed="true"],
.zone--mist .chip--active { background: var(--ink); border-color: var(--ink); color: var(--snow); }

.zone--mist .stat__num { color: var(--ink); }
.zone--mist .media { border-color: rgba(10, 26, 38, 0.14); }
.zone--mist .zone-label { border-color: rgba(10, 26, 38, 0.2); background: rgba(10, 26, 38, 0.03); color: #2A4457; }
.zone--mist .zone-label__no { background: rgba(10, 26, 38, 0.08); color: var(--ink); }
.zone--mist .btn--ghost { border-color: rgba(10, 26, 38, 0.22); color: var(--ink); background: transparent; }
.zone--mist .btn--ghost:hover { border-color: var(--ink); color: var(--ink); }
.zone--mist hr { background: rgba(10, 26, 38, 0.12); }

/* ---------- 7. 展签 / 章节头 ---------- */
.zone-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 5px 14px 5px 6px;
  border: 1px solid var(--edge);
  border-radius: var(--r-pill);
  background: rgba(111, 211, 242, 0.05);
  color: var(--glacier);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
}

.zone-label__no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 24px;
  height: 22px;
  padding: 0 6px;
  border-radius: var(--r-pill);
  background: rgba(111, 211, 242, 0.16);
  color: var(--ice);
  font-size: 10.5px;
  letter-spacing: 0.06em;
}

.sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 28px;
  margin-bottom: 26px;
}

.sec-title {
  font-size: clamp(28px, 4vw, 40px);
  letter-spacing: -0.01em;
  color: var(--snow);
}

.sec-title .num {
  margin-right: 0.45em;
  font-family: var(--mono);
  font-size: 0.5em;
  color: var(--ice);
  letter-spacing: 0.06em;
  vertical-align: 0.28em;
}

.sec-lead {
  max-width: 42em;
  margin-top: 12px;
  color: var(--slate);
  font-size: 16px;
}

/* ---------- 8. 正文 ---------- */
.prose {
  max-width: 38em;
  color: var(--snow);
  font-size: 17px;
  line-height: 1.85;
}

.prose h3 { margin: 30px 0 10px; }
.prose p + p { margin-top: 14px; }

.prose a {
  color: var(--ice);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.prose ul, .prose ol { display: grid; gap: 9px; margin-top: 14px; }

.prose li { position: relative; padding-left: 20px; }

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: var(--ice);
  opacity: 0.8;
}

/* ---------- 9. 卡片 / 胶囊 / 按钮 ---------- */
.card {
  padding: 22px;
  border: 1px solid var(--edge);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, rgba(16, 42, 60, 0.55), rgba(6, 18, 29, 0.4));
  transition: border-color 0.22s ease, transform 0.22s ease, background 0.22s ease;
}
.card:hover {
  border-color: rgba(111, 211, 242, 0.55);
  transform: translateY(-2px);
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border: 1px solid var(--edge);
  border-radius: var(--r-pill);
  background: rgba(111, 211, 242, 0.05);
  color: var(--glacier);
  font-size: 13.5px;
  line-height: 1.4;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}
.chip:hover { border-color: var(--ice); color: var(--snow); }
.chip[aria-pressed="true"],
.chip--active {
  background: var(--ice);
  border-color: var(--ice);
  color: var(--ink);
  font-weight: 700;
}
.chip--neon { border-color: rgba(76, 224, 160, 0.45); background: rgba(76, 224, 160, 0.1); color: var(--neon); }
.chip--amber { border-color: rgba(255, 156, 74, 0.45); background: rgba(255, 156, 74, 0.1); color: var(--amber); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.01em;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}
.btn--solid { background: var(--ice); color: var(--ink); }
.btn--solid:hover { background: #93E3F8; transform: translateY(-1px); }
.btn--ghost { border-color: var(--edge); background: rgba(111, 211, 242, 0.05); color: var(--snow); }
.btn--ghost:hover { border-color: var(--ice); color: var(--ice); }
.btn--neon { border-color: rgba(76, 224, 160, 0.45); background: rgba(76, 224, 160, 0.12); color: var(--neon); }
.btn--neon:hover { background: rgba(76, 224, 160, 0.2); }
.btn--sm { padding: 8px 16px; font-size: 13px; }

/* ---------- 10. 数据指标 ---------- */
.stat { display: flex; flex-direction: column; gap: 6px; }

.stat__num {
  font-family: var(--mono);
  font-size: 64px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--snow);
  transition: color 0.22s ease, transform 0.22s ease;
}
.stat__num--card { font-size: 32px; }
.stat__num--inline { font-size: 16px; }

.stat__unit {
  margin-left: 0.15em;
  font-size: 0.4em;
  font-weight: 400;
  letter-spacing: 0;
  color: var(--slate);
}

.stat__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--slate);
}

.stat:hover .stat__num { color: var(--neon); transform: scale(1.04); }
.stat--ice .stat__num { color: var(--ice); }
.stat--ice:hover .stat__num { color: var(--glacier); }
.stat--neon .stat__num { color: var(--neon); }
.stat--amber .stat__num { color: var(--amber); }

/* ---------- 11. 图片容器基础规则 ---------- */
.media {
  position: relative;
  width: 100%;
  border: 1px solid var(--edge);
  border-radius: var(--r-xl);
  overflow: hidden;
  isolation: isolate;
  background:
    radial-gradient(120% 120% at 14% 8%, rgba(111, 211, 242, 0.22), transparent 62%),
    linear-gradient(160deg, #0B2033, #06121D 66%);
}

.media::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(191, 233, 248, 0.10) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(191, 233, 248, 0.10) 1px, transparent 1px);
  background-size: 36px 36px;
}

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

.media--16x9 { aspect-ratio: 16 / 9; }
.media--3x2 { aspect-ratio: 3 / 2; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--portrait { aspect-ratio: 4 / 5; }
.media--fill { min-height: 220px; }

.media__caption {
  display: block;
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--slate-dim);
}

/* ---------- 12. 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--slate);
}
.crumbs li { display: flex; align-items: center; gap: 8px; }
.crumbs li + li::before { content: "/"; color: var(--edge); }
.crumbs a:hover { color: var(--ice); }
.crumbs [aria-current="page"] { color: var(--glacier); }

/* ---------- 13. 工具类 ---------- */
.u-mono { font-family: var(--mono); letter-spacing: 0.04em; }
.u-ice { color: var(--ice); }
.u-neon { color: var(--neon); }
.u-amber { color: var(--amber); }
.u-slate { color: var(--slate); }

/* =========================================================
   14. 头部：移动端顶部条形 → 桌面端左侧轨道
   ========================================================= */
.rail-header {
  position: sticky;
  top: 0;
  z-index: 80;
  display: flex;
  align-items: center;
  gap: 12px;
  height: 62px;
  padding: 0 16px;
  border-bottom: 1px solid var(--edge);
  background: rgba(6, 18, 29, 0.94);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.rail-header__bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 90;
  height: 2px;
  background: rgba(29, 64, 88, 0.6);
  pointer-events: none;
}

.rail-header__progress {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--ice), var(--neon) 70%, var(--amber));
  transition: transform 0.12s linear;
}

.rail-header__brand {
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  min-width: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand__mark {
  position: relative;
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  border: 1px solid var(--ice);
  border-radius: 10px;
  background:
    radial-gradient(circle at 32% 26%, rgba(111, 211, 242, 0.4), rgba(76, 224, 160, 0.12) 62%, transparent 74%);
  box-shadow: 0 0 0 4px rgba(111, 211, 242, 0.06);
}
.brand__mark::before {
  content: "";
  position: absolute;
  inset: 7px;
  border: 1px solid var(--glacier);
  border-radius: 50%;
}
.brand__mark::after {
  content: "";
  position: absolute;
  top: 4px;
  bottom: 4px;
  left: 50%;
  width: 1px;
  background: var(--glacier);
  transform: translateX(-0.5px);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  line-height: 1.2;
  min-width: 0;
}

.brand__line {
  font-size: 15px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--snow);
}

.brand__sub {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.16em;
  color: var(--slate-dim);
  white-space: nowrap;
}

/* 抽屉开关 */
.nav-toggle {
  position: relative;
  z-index: 88;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--edge);
  border-radius: var(--r-pill);
  background: rgba(111, 211, 242, 0.06);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--glacier);
  transition: border-color 0.2s ease, color 0.2s ease;
}
.nav-toggle:hover { border-color: var(--ice); color: var(--ice); }

.nav-toggle__bars {
  position: relative;
  width: 16px;
  height: 10px;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: currentColor;
  transition: transform 0.24s ease;
}
.nav-toggle__bars::before { top: 1px; }
.nav-toggle__bars::after { bottom: 1px; }

.nav-toggle[data-open="true"] .nav-toggle__bars::before { transform: translateY(3.5px) rotate(45deg); }
.nav-toggle[data-open="true"] .nav-toggle__bars::after { transform: translateY(-3.5px) rotate(-45deg); }
.nav-toggle[data-open="true"] { border-color: var(--ice); color: var(--ice); }

/* 抽屉遮罩 */
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 82;
  background: rgba(3, 9, 15, 0.62);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.28s ease;
}
.nav-scrim[data-open="true"] { opacity: 1; pointer-events: auto; }

/* 导航（移动端抽屉） */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 86;
  width: min(84vw, 320px);
  padding: 78px 18px 26px;
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--edge);
  background: linear-gradient(180deg, #08192A, #06121D 62%);
  overflow-y: auto;
  transform: translateX(-102%);
  visibility: hidden;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.3s ease;
}
.site-nav[data-open="true"] { transform: translateX(0); visibility: visible; }

.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.site-nav__link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 13px 14px;
  border-radius: var(--r-md);
  color: var(--glacier);
  font-size: 15px;
  transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}
.site-nav__link:hover { background: rgba(111, 211, 242, 0.1); color: var(--snow); }
.site-nav__link[aria-current="page"] {
  background: rgba(111, 211, 242, 0.14);
  color: var(--ice);
  box-shadow: inset 2px 0 0 var(--ice);
}

.site-nav__idx {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--slate-dim);
}
.site-nav__link[aria-current="page"] .site-nav__idx { color: var(--ice); }

.site-nav__label { line-height: 1.3; }

.site-nav__foot {
  display: grid;
  gap: 10px;
  margin-top: 26px;
  padding-top: 18px;
  border-top: 1px solid var(--grid);
}

.site-nav__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 18px;
  border-radius: var(--r-pill);
  background: var(--ice);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
}
.site-nav__cta:hover { background: #93E3F8; }

.site-nav__meta {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--slate-dim);
  word-break: break-all;
}

.rail-header__foot { display: none; }

/* ---------- 桌面端：左侧轨道 ---------- */
@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }

  .rail-header {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--rail-w);
    height: auto;
    flex-direction: column;
    align-items: center;
    gap: 0;
    padding: 22px 0 18px;
    border-right: 1px solid var(--edge);
    border-bottom: 0;
    background: linear-gradient(180deg, rgba(7, 23, 38, 0.98), rgba(6, 18, 29, 0.99));
  }

  .rail-header__brand {
    flex: 0 0 auto;
    width: 100%;
    justify-content: center;
    padding: 0 6px 18px;
    border-bottom: 1px solid var(--grid);
  }

  .rail-header .brand {
    flex-direction: column;
    align-items: center;
    gap: 9px;
    text-align: center;
  }
  .rail-header .brand__mark { width: 34px; height: 34px; border-radius: 12px; }
  .rail-header .brand__mark::before { inset: 9px; }
  .rail-header .brand__mark::after { top: 5px; bottom: 5px; }
  .rail-header .brand__text { align-items: center; }
  .rail-header .brand__line { font-size: 14px; }
  .rail-header .brand__sub { font-size: 9px; letter-spacing: 0.14em; }

  .nav-toggle { display: none; }
  .nav-scrim { display: none; }

  .site-nav {
    position: static;
    width: 100%;
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    padding: 14px 0;
    border: 0;
    background: none;
    overflow: visible;
    transform: none;
    visibility: visible;
    transition: none;
  }

  .rail-header .site-nav__list {
    display: flex;
    flex-direction: column;
    gap: 0;
    margin: auto 0;
  }

  .rail-header .site-nav__link {
    flex-direction: column;
    align-items: center;
    gap: 5px;
    width: 100%;
    padding: 13px 6px;
    border-radius: 0;
    border-right: 2px solid transparent;
    color: var(--slate);
    font-size: 13px;
    line-height: 1.3;
  }
  .rail-header .site-nav__link:hover {
    background: rgba(111, 211, 242, 0.06);
    color: var(--snow);
  }
  .rail-header .site-nav__link[aria-current="page"] {
    background: linear-gradient(90deg, rgba(111, 211, 242, 0.14), rgba(111, 211, 242, 0));
    box-shadow: none;
    border-right-color: var(--ice);
    color: var(--ice);
  }
  .rail-header .site-nav__idx { font-size: 10px; letter-spacing: 0.08em; }
  .rail-header .site-nav__link[aria-current="page"] .site-nav__idx { color: var(--ice); }

  .rail-header .site-nav__foot { display: none; }

  .rail-header__foot {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding-top: 16px;
    border-top: 1px solid var(--grid);
  }
}

.rail-chip {
  padding: 4px 9px;
  border: 1px solid var(--edge);
  border-radius: var(--r-pill);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--slate);
  white-space: nowrap;
}
.rail-chip--live {
  border-color: rgba(76, 224, 160, 0.45);
  background: rgba(76, 224, 160, 0.08);
  color: var(--neon);
}

/* 平板微调 */
@media (min-width: 640px) and (max-width: 1023.98px) {
  .rail-header { height: 68px; padding: 0 22px; }
  .site-nav { width: min(62vw, 340px); }
}

/* =========================================================
   15. 页脚
   ========================================================= */
.site-footer {
  position: relative;
  margin-top: 0;
  padding: 56px 0 0;
  border-top: 1px solid var(--edge);
  background:
    radial-gradient(900px 320px at 12% 0%, rgba(111, 211, 242, 0.10), transparent 70%),
    linear-gradient(180deg, #071726, #06121D 58%);
}

.site-footer__inner {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gut);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.site-footer__brand {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.brand--footer {
  flex-direction: row;
  align-items: center;
  gap: 12px;
  text-align: left;
}
.brand--footer .brand__text { align-items: flex-start; }
.brand--footer .brand__line { font-size: 16px; }

.site-footer__tagline {
  max-width: 30em;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--slate);
}

.site-footer__title {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.18em;
  color: var(--ice);
}

.site-footer__links {
  display: grid;
  gap: 10px;
  font-size: 14.5px;
}

.site-footer__links a {
  position: relative;
  display: inline-block;
  padding-left: 15px;
  color: #C9DBE5;
  transition: color 0.2s ease;
}
.site-footer__links a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 6px;
  height: 1px;
  background: var(--edge);
  transition: width 0.2s ease, background 0.2s ease;
}
.site-footer__links a:hover { color: var(--ice); }
.site-footer__links a:hover::before { width: 10px; background: var(--ice); }

.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 28px;
  margin-top: 44px;
  padding: 20px 0 26px;
  border-top: 1px solid var(--grid);
}

.site-footer__contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 26px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--slate);
}

.site-footer__kv {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  flex-wrap: wrap;
}

.site-footer__k {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--slate-dim);
}

.site-footer__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 16px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--slate-dim);
}

.site-footer__icp {
  padding: 5px 12px;
  border: 1px solid var(--edge);
  border-radius: var(--r-pill);
  color: var(--glacier);
}

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border: 1px solid var(--edge);
  border-radius: var(--r-pill);
  background: rgba(111, 211, 242, 0.06);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--glacier);
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}
.to-top:hover { border-color: var(--ice); color: var(--ice); background: rgba(111, 211, 242, 0.12); }
.to-top[hidden] { display: none; }

@media (min-width: 640px) {
  .site-footer__grid { grid-template-columns: 1fr 1fr; gap: 34px; }
  .site-footer__brand { grid-column: span 2; }
}

@media (min-width: 1024px) {
  .site-footer { padding-top: 64px; }
  .site-footer__grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 32px;
  }
  .site-footer__brand { grid-column: auto; }
}

/* =========================================================
   16. 进入视口动画
   ========================================================= */
.has-motion [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
}
.has-motion [data-reveal].is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 0.32s ease-out, transform 0.32s ease-out;
}

/* =========================================================
   17. 响应式细节
   ========================================================= */
@media (max-width: 900px) {
  .span-3, .span-4, .span-5, .span-6,
  .span-7, .span-8, .span-9, .span-12 {
    grid-column: span 12;
  }
  .zone { padding: 48px 0; }
  .zone--tight { padding: 32px 0; }
  .sec-head { align-items: flex-start; }
}

@media (max-width: 480px) {
  body { font-size: 16px; }
  :root { --gut: 18px; }
  .stat__num { font-size: 46px; }
  .stat__num--card { font-size: 28px; }
  .btn { width: 100%; }
  .to-top { width: auto; }
}

@media (max-width: 1023.98px) {
  body[data-nav-open="true"] { overflow: hidden; }
}

/* =========================================================
   18. 降低动效
   ========================================================= */
@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;
    transition-delay: 0ms !important;
  }

  .has-motion [data-reveal] { opacity: 1; transform: none; }
  .site-nav { transition: none; }
  .stat:hover .stat__num { transform: none; }
  .card:hover { transform: none; }
}