/* ==========================================================================
   19体育主站 · /assets/site.css
   夜间球场聚光灯下的实时数据流 · 共享外壳与基础组件
   ========================================================================== */

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

* { margin: 0; }

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

body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--ink-950);
  color: var(--slate-100);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
ul, ol { list-style: none; padding: 0; }
a { color: inherit; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink-950: #04070F;
  --ink-900: #081227;
  --ink-800: #0E1E3C;
  --line-600: #1C3059;
  --lime-400: #C8F24F;
  --lime-200: #E9FFB0;
  --amber-500: #FF8A2B;
  --amber-300: #FFBB80;
  --cyan-400: #49D6E8;
  --slate-100: #E7EDF8;
  --slate-400: #93A4C2;
  --white: #FFFFFF;

  --font-display: "Archivo Narrow", "Oswald", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;
  --font-body: Inter, "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;

  --shell-max: 1280px;
  --gutter: clamp(16px, 4vw, 40px);
  --header-h: 66px;
  --radius: 10px;
  --radius-sm: 8px;
  --shadow-panel: 0 4px 24px rgba(0, 0, 0, .45);
  --ease: cubic-bezier(.2, .7, .3, 1);
}

/* ---------- 3. 底层背景：网格纹 + 聚光 ---------- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(58% 42% at 80% -6%, rgba(200, 242, 79, .09), transparent 68%),
    radial-gradient(46% 40% at 4% 26%, rgba(73, 214, 232, .07), transparent 72%),
    radial-gradient(40% 34% at 96% 88%, rgba(255, 138, 43, .05), transparent 70%),
    linear-gradient(rgba(28, 48, 89, .34) 1px, transparent 1px),
    linear-gradient(90deg, rgba(28, 48, 89, .34) 1px, transparent 1px);
  background-size: auto, auto, auto, 72px 72px, 72px 72px;
}

::selection { background: var(--lime-400); color: var(--ink-950); }

/* ---------- 4. 中文排版与标题层级 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -.01em;
  line-height: 1.2;
  color: var(--white);
}

h1 { font-size: clamp(2rem, 5vw, 3.4rem); }
h2 { font-size: clamp(1.45rem, 3vw, 2.15rem); }
h3 { font-size: clamp(1.12rem, 2vw, 1.45rem); }
h4 { font-size: 1.02rem; }

.display {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.02;
  color: var(--white);
  font-size: clamp(2.4rem, 7vw, 6rem);
}
.display--md { font-size: clamp(1.9rem, 4.6vw, 3.5rem); }
.display--sm { font-size: clamp(1.5rem, 3.2vw, 2.3rem); }

.mono { font-family: var(--font-mono); letter-spacing: .02em; }

.num {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--lime-400);
  letter-spacing: .01em;
  font-variant-numeric: tabular-nums;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--lime-400);
}
.eyebrow::before {
  content: "";
  display: block;
  width: 22px;
  height: 1px;
  background: var(--lime-400);
}

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

/* ---------- 5. 焦点可见 ---------- */
:focus-visible {
  outline: 2px solid var(--lime-400);
  outline-offset: 2px;
  border-radius: 4px;
}
a:focus:not(:focus-visible),
button:focus:not(:focus-visible) { outline: none; }

#main-content {
  outline: none;
  scroll-margin-top: calc(var(--header-h) + 18px);
}

/* ---------- 6. 布局基础容器 ---------- */
.container {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: 760px; }

.main-content { padding-top: clamp(24px, 4vw, 48px); }

.section { padding-block: clamp(34px, 6vw, 78px); }

.split {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(22px, 4vw, 54px);
  align-items: start;
}
.split--wide { grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); }

.rail {
  position: sticky;
  top: calc(var(--header-h) + 22px);
  align-self: start;
}

.grid { display: grid; gap: clamp(14px, 2vw, 24px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.edge-cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), 0 100%);
}

/* ---------- 7. 面板 / 卡片 ---------- */
.panel {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line-600);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(14, 30, 60, .74), rgba(8, 18, 39, .74));
  box-shadow: var(--shadow-panel);
}
.panel--flat {
  box-shadow: none;
  background: rgba(8, 18, 39, .6);
}

.card {
  position: relative;
  padding: clamp(16px, 2vw, 24px);
  border: 1px solid var(--line-600);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(14, 30, 60, .66), rgba(8, 18, 39, .66));
  transition: border-color .2s var(--ease), transform .2s var(--ease);
}
.card:hover {
  border-color: rgba(200, 242, 79, .42);
  transform: translateY(-2px);
}
.card-title {
  margin-bottom: 6px;
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--white);
}
.card-meta {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
  color: var(--slate-400);
}

/* ---------- 8. 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: .92rem;
  font-weight: 600;
  letter-spacing: .01em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .18s var(--ease), background-color .18s var(--ease),
              border-color .18s var(--ease), color .18s var(--ease), box-shadow .18s var(--ease);
}
.btn--primary {
  background: linear-gradient(135deg, var(--amber-500), #f06c12);
  color: #1a0c02;
  box-shadow: 0 8px 24px rgba(255, 138, 43, .24);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(255, 138, 43, .34); }
.btn--lime {
  background: linear-gradient(135deg, var(--lime-400), #9fd833);
  color: var(--ink-950);
  box-shadow: 0 8px 24px rgba(200, 242, 79, .18);
}
.btn--lime:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(200, 242, 79, .26); }
.btn--ghost {
  border-color: var(--line-600);
  background: rgba(14, 30, 60, .5);
  color: var(--slate-100);
}
.btn--ghost:hover {
  border-color: var(--lime-400);
  color: var(--lime-200);
  transform: translateY(-2px);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line-600);
  border-radius: 4px;
  background: rgba(14, 30, 60, .5);
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
  color: var(--slate-400);
  text-decoration: none;
  white-space: nowrap;
  transition: color .16s var(--ease), border-color .16s var(--ease), transform .16s var(--ease);
}
a.tag:hover, a.tag:focus-visible {
  color: var(--lime-200);
  border-color: var(--lime-400);
  transform: translateY(-2px);
}
.tag--lime { color: var(--lime-200); border-color: rgba(200, 242, 79, .42); }
.tag--amber { color: var(--amber-300); border-color: rgba(255, 138, 43, .46); }
.tag-cloud { display: flex; flex-wrap: wrap; gap: 8px; }

/* ---------- 9. 面包屑 / 目录 / 正文 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 clamp(18px, 3vw, 30px);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .06em;
  color: var(--slate-400);
}
.breadcrumb li { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb li + li::before { content: "/"; color: var(--line-600); }
.breadcrumb a { color: var(--slate-400); text-decoration: none; }
.breadcrumb a:hover, .breadcrumb a:focus-visible { color: var(--lime-200); }
.breadcrumb [aria-current="page"] { color: var(--lime-400); }

.toc { display: grid; gap: 2px; }
.toc a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: .86rem;
  color: var(--slate-400);
  text-decoration: none;
  transition: color .16s var(--ease), background-color .16s var(--ease), border-color .16s var(--ease);
}
.toc a:hover { color: var(--white); background: rgba(28, 48, 89, .42); }
.toc a.is-active {
  color: var(--white);
  border-left-color: var(--lime-400);
  background: rgba(28, 48, 89, .58);
}

.prose { font-size: 1.01rem; line-height: 1.85; color: var(--slate-100); }
.prose p { max-width: 68ch; margin-bottom: 1.1em; }
.prose h2, .prose h3 { margin: 1.8em 0 .7em; }
.prose ul, .prose ol { max-width: 68ch; margin: 0 0 1.2em 1.2em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li { margin-bottom: .5em; }
.prose a {
  color: var(--cyan-400);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.prose a:hover { color: var(--lime-200); }

/* ---------- 10. 图片容器基座（页面阶段放置资源） ---------- */
.media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-600);
  border-radius: var(--radius);
  background: var(--ink-800);
}
.media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(.86) contrast(1.08) saturate(.92);
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(73, 214, 232, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(73, 214, 232, .07) 1px, transparent 1px);
  background-size: 32px 32px;
  mix-blend-mode: screen;
}
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--portfolio { aspect-ratio: 3 / 4; }

.media-placeholder {
  display: grid;
  place-items: center;
  min-height: 180px;
  padding: 20px;
  text-align: center;
  border: 1px dashed var(--line-600);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 120% at 82% 0%, rgba(73, 214, 232, .13), transparent 62%),
    radial-gradient(96% 96% at 0% 100%, rgba(200, 242, 79, .11), transparent 62%),
    var(--ink-800);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--slate-400);
}

.media-caption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 12px 14px;
  background: linear-gradient(180deg, transparent, rgba(4, 7, 15, .9));
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
  color: var(--slate-100);
  z-index: 2;
}

/* ---------- 11. 跳转链 ---------- */
.skip-link {
  position: absolute;
  left: var(--gutter);
  top: 8px;
  z-index: 200;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background: var(--lime-400);
  color: var(--ink-950);
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform .2s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 12. 头部命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(4, 7, 15, .84);
  border-bottom: 1px solid var(--line-600);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  transition: background-color .2s var(--ease), box-shadow .2s var(--ease);
}
.site-header.is-stuck {
  background: rgba(4, 7, 15, .95);
  box-shadow: var(--shadow-panel);
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 24px);
  width: 100%;
  max-width: var(--shell-max);
  min-height: var(--header-h);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--slate-100);
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: linear-gradient(150deg, var(--lime-400), #7fc22d);
  color: var(--ink-950);
  font-family: var(--font-mono);
  font-size: .82rem;
  font-weight: 700;
  box-shadow: 0 0 0 1px rgba(200, 242, 79, .35), 0 6px 18px rgba(200, 242, 79, .16);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-name {
  font-family: var(--font-display);
  font-size: 1.06rem;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--white);
}
.brand-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .1em;
  color: var(--slate-400);
}

.status-dot {
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--lime-400);
  box-shadow: 0 0 0 3px rgba(200, 242, 79, .16);
  animation: statusPulse 2.4s var(--ease) infinite;
}
@keyframes statusPulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 3px rgba(200, 242, 79, .16); }
  50% { opacity: .58; box-shadow: 0 0 0 7px rgba(200, 242, 79, .04); }
}

/* 导航 */
.nav {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.4vw, 20px);
  flex: 1 1 auto;
  justify-content: flex-end;
  margin-left: auto;
}
.nav-list {
  display: flex;
  align-items: stretch;
  gap: 2px;
  list-style: none;
  padding: 0;
}
.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 10px 11px;
  border-radius: var(--radius-sm);
  font-size: .86rem;
  font-weight: 500;
  color: var(--slate-400);
  text-decoration: none;
  transition: color .18s var(--ease), background-color .18s var(--ease);
}
.nav-index {
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .04em;
  color: rgba(147, 164, 194, .55);
  transition: color .18s var(--ease);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 4px;
  height: 1.5px;
  background: var(--lime-400);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .22s var(--ease);
}
.nav-link:hover,
.nav-link:focus-visible {
  color: var(--white);
  background: rgba(28, 48, 89, .42);
}
.nav-link:hover .nav-index { color: var(--lime-400); }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--white); }
.nav-link[aria-current="page"] .nav-index { color: var(--lime-400); }
.nav-link[aria-current="page"]::after { transform: scaleX(1); }
.nav-link[aria-current="page"]::before {
  content: "";
  position: absolute;
  top: 6px;
  right: 3px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--lime-400);
  box-shadow: 0 0 8px rgba(200, 242, 79, .8);
}

.nav-utils {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}

/* 等宽小按钮 */
.chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 13px;
  border: 1px solid var(--line-600);
  border-radius: 999px;
  background: rgba(14, 30, 60, .6);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .06em;
  color: var(--slate-100);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color .18s var(--ease), color .18s var(--ease),
              transform .18s var(--ease), background-color .18s var(--ease);
}
.chip--ghost:hover,
.chip--ghost:focus-visible {
  border-color: var(--lime-400);
  color: var(--lime-200);
  transform: translateY(-2px);
}
.chip--cta {
  border-color: rgba(255, 138, 43, .55);
  background: linear-gradient(135deg, rgba(255, 138, 43, .2), rgba(255, 138, 43, .06));
  color: var(--amber-300);
}
.chip--cta:hover,
.chip--cta:focus-visible {
  border-color: var(--amber-500);
  background: linear-gradient(135deg, rgba(255, 138, 43, .34), rgba(255, 138, 43, .12));
  color: #fff;
  transform: translateY(-2px);
}

/* 移动端切换按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  min-width: 44px;
  min-height: 44px;
  margin-left: auto;
  padding: 6px 13px;
  border: 1px solid var(--line-600);
  border-radius: 999px;
  background: rgba(14, 30, 60, .6);
  color: var(--slate-100);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  cursor: pointer;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--lime-400); color: var(--lime-200); }
.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--lime-400);
  transition: background-color .2s var(--ease);
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--lime-400);
  transition: transform .22s var(--ease), top .22s var(--ease);
}
.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { top: 0; transform: rotate(-45deg); }

/* 滚动进度轨 */
.header-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
  pointer-events: none;
}
.header-meter-fill {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--lime-400), var(--cyan-400) 58%, var(--amber-500));
  transition: transform .1s linear;
}

/* ---------- 13. 页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: clamp(52px, 8vw, 116px);
  border-top: 1px solid var(--line-600);
  background:
    linear-gradient(180deg, rgba(8, 18, 39, .5), rgba(4, 7, 15, .96) 58%),
    var(--ink-950);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -140px;
  left: 50%;
  width: min(900px, 130%);
  height: 300px;
  transform: translateX(-50%);
  background: radial-gradient(closest-side, rgba(200, 242, 79, .1), transparent 72%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(220px, 1.5fr) repeat(3, minmax(150px, 1fr));
  gap: clamp(24px, 4vw, 50px);
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: clamp(38px, 6vw, 68px) var(--gutter) clamp(26px, 4vw, 40px);
}

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--white);
}
.footer-brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background: linear-gradient(150deg, var(--lime-400), #7fc22d);
  color: var(--ink-950);
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 700;
}
.footer-brand-name {
  font-family: var(--font-display);
  font-size: 1.16rem;
  font-weight: 700;
  letter-spacing: -.01em;
}
.footer-slogan {
  max-width: 34ch;
  margin-top: 14px;
  font-size: .88rem;
  line-height: 1.75;
  color: var(--slate-400);
}
.footer-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .06em;
  color: var(--slate-400);
}

.footer-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--lime-400);
}
.footer-title::after {
  content: "";
  flex: 1 1 auto;
  height: 1px;
  background: linear-gradient(90deg, var(--line-600), transparent);
}

.footer-col ul { display: grid; gap: 9px; }
.footer-col a {
  display: inline-block;
  font-size: .87rem;
  color: var(--slate-400);
  text-decoration: none;
  transition: color .16s var(--ease), transform .16s var(--ease);
}
.footer-col a:hover,
.footer-col a:focus-visible {
  color: var(--lime-200);
  transform: translateX(3px);
}

.footer-contact { gap: 13px; }
.footer-contact li { display: grid; gap: 3px; }
.footer-contact-key {
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--lime-400);
}
.footer-contact-val {
  font-size: .85rem;
  line-height: 1.6;
  color: var(--slate-100);
  word-break: break-word;
}

.footer-legal {
  position: relative;
  border-top: 1px solid var(--line-600);
  background: rgba(4, 7, 15, .72);
}
.footer-legal-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 18px var(--gutter);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .04em;
  color: var(--slate-400);
}
.footer-legal-nav { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-legal-nav a { color: var(--slate-400); text-decoration: none; }
.footer-legal-nav a:hover,
.footer-legal-nav a:focus-visible { color: var(--lime-200); }
.footer-copy { color: var(--slate-400); }
.footer-icp { color: var(--slate-400); }

/* ---------- 14. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-width: 44px;
  min-height: 44px;
  padding: 0 15px;
  border: 1px solid var(--line-600);
  border-radius: 999px;
  background: rgba(8, 18, 39, .92);
  color: var(--slate-100);
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .12em;
  cursor: pointer;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .22s var(--ease), transform .22s var(--ease),
              visibility .22s, border-color .18s var(--ease), color .18s var(--ease);
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover,
.to-top:focus-visible { border-color: var(--lime-400); color: var(--lime-200); }
.to-top-arrow { font-size: .9rem; line-height: 1; }

/* ---------- 15. 滚动渐显 ---------- */
html.has-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .55s var(--ease), transform .55s var(--ease);
}
html.has-reveal [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1100px) {
  .footer-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 960px) {
  .split,
  .split--wide { grid-template-columns: minmax(0, 1fr); }

  .rail {
    position: static;
    top: auto;
  }

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

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

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 90;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    margin-left: 0;
    padding: 0 var(--gutter);
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    background: linear-gradient(180deg, rgba(8, 18, 39, .99), rgba(4, 7, 15, .99));
    border-bottom: 1px solid var(--line-600);
    box-shadow: var(--shadow-panel);
    transition: max-height .3s var(--ease), opacity .22s var(--ease), visibility .3s;
  }
  .nav[data-open] {
    max-height: min(78vh, 640px);
    overflow-y: auto;
    visibility: visible;
    opacity: 1;
    padding-bottom: 18px;
  }
  .nav-list { flex-direction: column; gap: 0; }
  .nav-list li { border-bottom: 1px solid rgba(28, 48, 89, .62); }
  .nav-link {
    width: 100%;
    min-height: 48px;
    justify-content: flex-start;
    padding: 13px 4px;
    border-radius: 0;
    font-size: .95rem;
  }
  .nav-link::after { left: 4px; right: auto; width: 30px; bottom: 8px; }
  .nav-link[aria-current="page"]::before { content: none; }
  .nav-index { font-size: .68rem; }
  .nav-utils { flex-direction: column; align-items: stretch; gap: 8px; padding-top: 16px; }
  .chip { min-height: 44px; font-size: .78rem; }
}

@media (max-width: 640px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }

  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-legal-inner { flex-direction: column; align-items: flex-start; }

  .brand-status { display: none; }

  .to-top-label { display: none; }
  .to-top { padding-inline: 14px; }
}

/* ---------- 17. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  .status-dot { animation: none; }

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

  .card:hover,
  .chip:hover,
  .btn:hover,
  .tag:hover,
  .footer-col a:hover { transform: none; }
}