/* ============================================================
   云体育赛场 · 共享样式表 /assets/site.css
   头部 / 页脚 / 排版 / 栅格 / 基础组件 / 图片容器
   ============================================================ */

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

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

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

ul, ol { list-style: none; }

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

button, input, select, textarea { font: inherit; color: inherit; }

a { color: inherit; }

/* ---------- 2. 变量 ---------- */
:root {
  --c-deep: #061527;
  --c-ink: #0D2440;
  --c-ink-2: #0A1D33;
  --c-cyan: #16E0D4;
  --c-cyan-deep: #0FA9C9;
  --c-green: #7DF06A;
  --c-orange: #FF8A3C;
  --c-white: #FFFFFF;
  --c-mist: #EAF3FB;
  --c-steel: #8AA4C0;
  --c-line: #1E3A5A;
  --c-violet: #5A63FF;

  --line-soft: rgba(30, 58, 90, 0.55);
  --line-mid: rgba(30, 58, 90, 0.78);

  --font-head: "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui,
    -apple-system, "Segoe UI", sans-serif;
  --font-body: var(--font-head);
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular,
    Menlo, Consolas, "Courier New", monospace;

  --w-max: 1440px;
  --pad-x: clamp(16px, 2.4vw, 34px);
  --rail-w: 264px;
  --radius: 12px;
  --ease-out: cubic-bezier(0.22, 0.7, 0.3, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--c-deep);
  background-image:
    radial-gradient(1200px 520px at 78% -8%, rgba(22, 224, 212, 0.13), transparent 68%),
    radial-gradient(900px 480px at 6% 12%, rgba(90, 99, 255, 0.12), transparent 70%),
    linear-gradient(180deg, #071a2e 0%, #061527 42%, #04101e 100%);
  background-attachment: fixed;
  color: var(--c-mist);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(30, 58, 90, 0.42) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 58, 90, 0.42) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.5;
  -webkit-mask-image: radial-gradient(ellipse 120% 80% at 50% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(ellipse 120% 80% at 50% 0%, #000 0%, transparent 78%);
}

body > * { position: relative; z-index: 1; }

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--c-mist);
}

h1 { font-size: clamp(34px, 4.4vw, 56px); }
h2 { font-size: clamp(26px, 3vw, 40px); }
h3 { font-size: clamp(20px, 2vw, 28px); }
h4 { font-size: clamp(18px, 1.5vw, 22px); }

p { line-height: 1.75; }

strong { font-weight: 700; color: var(--c-white); }

::selection {
  background: rgba(22, 224, 212, 0.32);
  color: var(--c-white);
}

:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- 4. 通用文本工具 ---------- */
.num,
.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.num { color: var(--c-white); }

/* ---------- 5. 跳过链接 ---------- */
.skip-link {
  position: fixed;
  top: -72px;
  left: 14px;
  z-index: 200;
  padding: 11px 18px;
  border-radius: 0 0 10px 10px;
  background: var(--c-cyan);
  color: #04131f;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 14px 30px -14px rgba(22, 224, 212, 0.9);
  transition: top 0.18s var(--ease-out);
}

.skip-link:focus {
  top: 0;
  outline-offset: 3px;
}

#main-content:focus { outline: none; }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 17px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.18s var(--ease-out), box-shadow 0.24s var(--ease-out),
    background-color 0.24s var(--ease-out), border-color 0.24s var(--ease-out),
    color 0.24s var(--ease-out);
}

.btn-primary {
  background: linear-gradient(135deg, var(--c-cyan) 0%, var(--c-cyan-deep) 100%);
  color: #04131f;
  box-shadow: 0 0 0 1px rgba(22, 224, 212, 0.35),
    0 14px 28px -16px rgba(22, 224, 212, 0.95);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 0 0 1px rgba(22, 224, 212, 0.6),
    0 20px 34px -16px rgba(22, 224, 212, 1);
}

.btn-ghost {
  border-color: var(--line-mid);
  background: rgba(13, 36, 64, 0.7);
  color: var(--c-mist);
}

.btn-ghost:hover {
  border-color: rgba(22, 224, 212, 0.55);
  color: var(--c-cyan);
  background: rgba(13, 36, 64, 0.95);
}

/* ---------- 7. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(6, 21, 39, 0.93);
  border-bottom: 1px solid var(--line-mid);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  backdrop-filter: blur(14px) saturate(150%);
}

.header-inner {
  width: 100%;
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.header-top {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 74px;
  padding: 10px 0;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  flex: 0 0 auto;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 9px;
  border: 1px solid rgba(22, 224, 212, 0.55);
  background: linear-gradient(150deg, rgba(22, 224, 212, 0.2), rgba(13, 36, 64, 0.9));
  color: var(--c-cyan);
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  box-shadow: inset 0 1px 0 rgba(234, 243, 251, 0.12),
    0 0 20px -8px rgba(22, 224, 212, 0.9);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand-name {
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--c-white);
  line-height: 1.1;
}

.brand-note {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.09em;
  color: var(--c-steel);
  line-height: 1.3;
}

/* 快捷动作 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}

.quick-link {
  padding: 8px 12px;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--c-steel);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.24s var(--ease-out), border-color 0.24s var(--ease-out),
    background-color 0.24s var(--ease-out);
}

.quick-link:hover {
  color: var(--c-cyan);
  border-color: rgba(22, 224, 212, 0.5);
  background: rgba(22, 224, 212, 0.08);
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  margin-left: 10px;
  padding: 10px 13px;
  border: 1px solid var(--line-mid);
  border-radius: 8px;
  background: rgba(13, 36, 64, 0.9);
  color: var(--c-mist);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: border-color 0.24s var(--ease-out), color 0.24s var(--ease-out);
}

.nav-toggle:hover { border-color: rgba(22, 224, 212, 0.55); color: var(--c-cyan); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--c-cyan);
  transition: transform 0.18s var(--ease-out), top 0.18s var(--ease-out);
}

.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { top: 8px; }

[data-nav-toggle][aria-expanded="true"] .nav-toggle-bars::before {
  top: 4px;
  transform: rotate(45deg);
}

[data-nav-toggle][aria-expanded="true"] .nav-toggle-bars::after {
  top: 4px;
  transform: rotate(-45deg);
}

/* 栏目导航 */
.site-nav {
  border-top: 1px solid var(--line-soft);
}

.nav-list {
  display: flex;
  align-items: stretch;
  gap: 2px;
  padding: 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-list::-webkit-scrollbar { display: none; }

.nav-link {
  display: block;
  padding: 12px 15px 11px;
  border-bottom: 2px solid transparent;
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--c-steel);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.24s var(--ease-out), background-color 0.24s var(--ease-out),
    border-color 0.24s var(--ease-out);
}

.nav-link:hover {
  color: var(--c-mist);
  background: rgba(22, 224, 212, 0.07);
}

.nav-link[aria-current="page"] {
  color: var(--c-cyan);
  border-bottom-color: var(--c-cyan);
  background: linear-gradient(180deg, rgba(22, 224, 212, 0.02), rgba(22, 224, 212, 0.12));
}

/* 头部脉冲装饰 */
.header-pulse {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  overflow: hidden;
  pointer-events: none;
}

.header-pulse::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 26%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--c-cyan), transparent);
  animation: headerPulse 6s linear infinite;
}

@keyframes headerPulse {
  0% { transform: translateX(-30%); opacity: 0; }
  12% { opacity: 1; }
  88% { opacity: 1; }
  100% { transform: translateX(430%); opacity: 0; }
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 6vw, 96px);
  background: linear-gradient(180deg, #061527 0%, #030d19 100%);
  border-top: 1px solid var(--line-mid);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(22, 224, 212, 0.7), rgba(125, 240, 106, 0.45), transparent);
}

.footer-inner {
  width: 100%;
  max-width: var(--w-max);
  margin: 0 auto;
  padding: clamp(38px, 4.6vw, 64px) var(--pad-x) 26px;
}

.footer-columns {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.5fr;
  gap: clamp(22px, 3vw, 46px);
}

.brand--footer .brand-mark {
  width: 34px;
  height: 34px;
  font-size: 15px;
}

.brand--footer .brand-name { font-size: 17px; }

.footer-desc {
  margin-top: 16px;
  max-width: 34ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-steel);
}

.footer-seasons {
  display: flex;
  align-items: baseline;
  gap: 9px;
  margin-top: 16px;
  font-size: 13.5px;
  color: var(--c-steel);
}

.footer-seasons .num {
  font-size: 26px;
  font-weight: 700;
  color: var(--c-cyan);
  line-height: 1;
}

.footer-title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.footer-list {
  display: grid;
  gap: 1px;
}

.footer-list a {
  position: relative;
  display: inline-block;
  padding: 7px 0 7px 12px;
  font-size: 15px;
  line-height: 1.5;
  color: var(--c-steel);
  text-decoration: none;
  transition: color 0.24s var(--ease-out), padding-left 0.24s var(--ease-out);
}

.footer-list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 5px;
  height: 1px;
  background: var(--c-steel);
  transform: translateY(-50%);
  transition: width 0.24s var(--ease-out), background-color 0.24s var(--ease-out);
}

.footer-list a:hover {
  color: var(--c-mist);
  padding-left: 15px;
}

.footer-list a:hover::before {
  width: 9px;
  background: var(--c-cyan);
}

.footer-list--contact li {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding: 8px 0;
  border-bottom: 1px dashed rgba(30, 58, 90, 0.5);
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--c-mist);
}

.footer-list--contact li:last-child { border-bottom: 0; }

.footer-key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-steel);
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 24px;
  margin-top: clamp(28px, 3.4vw, 44px);
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  line-height: 1.7;
  color: var(--c-steel);
}

.footer-meta p { margin: 0; }

.footer-copy { color: var(--c-mist); }

/* ---------- 9. 布局容器 ---------- */
.container {
  width: 100%;
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.section {
  padding: clamp(38px, 4.8vw, 74px) 0;
}

.section-head {
  margin-bottom: clamp(18px, 2.4vw, 32px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: linear-gradient(90deg, var(--c-cyan), transparent);
}

.section-title {
  margin: 0.4em 0 0.35em;
  font-size: clamp(26px, 3vw, 40px);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.lede {
  max-width: 42em;
  font-size: 17.5px;
  line-height: 1.75;
  color: var(--c-steel);
}

.prose {
  max-width: 42em;
  font-size: 17.5px;
  line-height: 1.75;
  color: var(--c-mist);
}

.prose p + p { margin-top: 0.95em; }

.prose a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(22, 224, 212, 0.4);
}

.prose a:hover { border-bottom-color: var(--c-cyan); }

/* ---------- 10. 栅格 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(12px, 1.6vw, 20px);
}

.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-12 { grid-column: span 12; }

/* ---------- 11. 侧边导览轨道 ---------- */
.rail-layout {
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  gap: clamp(20px, 3vw, 44px);
  width: 100%;
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.rail {
  position: sticky;
  top: 132px;
  align-self: start;
  padding: 18px 16px 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(13, 36, 64, 0.92), rgba(6, 21, 39, 0.92));
  box-shadow: inset 0 1px 0 rgba(234, 243, 251, 0.06),
    0 24px 48px -40px #000;
}

.rail-title {
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.rail-list { display: grid; gap: 2px; }

.rail-link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 10px;
  border-left: 2px solid transparent;
  border-radius: 6px;
  font-size: 14.5px;
  line-height: 1.45;
  color: var(--c-steel);
  text-decoration: none;
  transition: color 0.24s var(--ease-out), background-color 0.24s var(--ease-out),
    border-color 0.24s var(--ease-out);
}

.rail-link:hover {
  color: var(--c-mist);
  background: rgba(22, 224, 212, 0.07);
}

.rail-link[aria-current],
.rail-link.is-active {
  color: var(--c-cyan);
  border-left-color: var(--c-cyan);
  background: linear-gradient(90deg, rgba(22, 224, 212, 0.14), transparent);
}

.rail-index {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-steel);
  opacity: 0.85;
}

/* ---------- 12. 卡片与标签 ---------- */
.card {
  position: relative;
  padding: 18px;
  border: 1px solid var(--line-mid);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(13, 36, 64, 0.94), rgba(8, 24, 44, 0.94));
  box-shadow: inset 0 1px 0 rgba(234, 243, 251, 0.06),
    0 22px 46px -38px #000;
  transition: border-color 0.24s var(--ease-out), box-shadow 0.24s var(--ease-out);
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 40%;
  height: 2px;
  border-radius: var(--radius) 0 0 0;
  background: linear-gradient(90deg, var(--c-cyan), transparent);
  opacity: 0.85;
}

.card:hover {
  border-color: rgba(22, 224, 212, 0.45);
  box-shadow: inset 0 1px 0 rgba(234, 243, 251, 0.08),
    0 26px 54px -36px rgba(22, 224, 212, 0.35);
}

.card--accent { border-color: rgba(22, 224, 212, 0.4); }
.card--accent::before { right: 12%; }

.card-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.card-title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.card-body {
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--c-steel);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 9px;
  border: 1px solid var(--line-mid);
  border-radius: 4px;
  background: rgba(6, 21, 39, 0.7);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  line-height: 1;
  color: var(--c-steel);
}

.tag--cyan {
  color: var(--c-cyan);
  border-color: rgba(22, 224, 212, 0.48);
  background: rgba(22, 224, 212, 0.1);
}

.tag--green {
  color: var(--c-green);
  border-color: rgba(125, 240, 106, 0.45);
  background: rgba(125, 240, 106, 0.1);
}

.tag--orange {
  color: var(--c-orange);
  border-color: rgba(255, 138, 60, 0.45);
  background: rgba(255, 138, 60, 0.1);
}

.tag--violet {
  color: #A9AFFF;
  border-color: rgba(90, 99, 255, 0.5);
  background: rgba(90, 99, 255, 0.12);
}

/* ---------- 13. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 9px;
  padding: 14px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--c-steel);
}

.breadcrumb a {
  color: var(--c-steel);
  text-decoration: none;
  transition: color 0.24s var(--ease-out);
}

.breadcrumb a:hover { color: var(--c-cyan); }

.breadcrumb .sep {
  color: var(--c-steel);
  opacity: 0.5;
}

.breadcrumb [aria-current="page"] { color: var(--c-mist); }

/* ---------- 14. 图片 / 视觉容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-mid);
  border-radius: var(--radius);
  background: linear-gradient(160deg, #0B2138 0%, #071A2E 55%, #061527 100%);
  box-shadow: inset 0 1px 0 rgba(234, 243, 251, 0.05);
}

.media-frame img,
.media-frame svg,
.media-frame video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    180deg,
    rgba(22, 224, 212, 0.06) 0px,
    rgba(22, 224, 212, 0.06) 1px,
    transparent 1px,
    transparent 4px
  );
  mix-blend-mode: screen;
}

.media-frame--21x9 { aspect-ratio: 21 / 9; }
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }

.media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  line-height: 1.7;
  color: var(--c-steel);
}

/* ---------- 15. 滚动进度（JS 注入） ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  z-index: 120;
  pointer-events: none;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--c-cyan) 0%, var(--c-green) 62%, var(--c-orange) 100%);
  box-shadow: 0 0 14px rgba(22, 224, 212, 0.65);
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1100px) {
  .quick-link { display: none; }
  .footer-columns { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 1024px) {
  .rail-layout { grid-template-columns: minmax(0, 1fr); }
  .rail { position: static; top: auto; }
  .span-3, .span-4, .span-5 { grid-column: span 6; }
  .span-7, .span-8 { grid-column: span 12; }
}

@media (max-width: 900px) {
  body { font-size: 16.5px; }

  .header-top { min-height: 64px; }

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

  .site-nav {
    display: none;
    border-top: 1px solid var(--line-soft);
  }

  .site-nav[data-open] {
    display: block;
    animation: navIn 0.18s var(--ease-out) both;
  }

  .nav-list {
    flex-direction: column;
    gap: 0;
    padding: 4px 0 12px;
    overflow: visible;
  }

  .nav-link {
    padding: 14px 8px;
    border-bottom: 1px solid rgba(30, 58, 90, 0.42);
    border-left: 2px solid transparent;
  }

  .nav-link[aria-current="page"] {
    border-bottom-color: rgba(30, 58, 90, 0.42);
    border-left-color: var(--c-cyan);
    background: linear-gradient(90deg, rgba(22, 224, 212, 0.15), transparent);
  }

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

@media (max-width: 680px) {
  .header-actions .btn-primary { display: none; }
  .brand-note { display: none; }
  .footer-columns { grid-template-columns: 1fr; }
  .footer-list--contact li { grid-template-columns: 48px minmax(0, 1fr); }
  .grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-12 {
    grid-column: span 4;
  }
  .footer-meta { gap: 6px 16px; }
}

/* ---------- 17. 减弱动效 ---------- */
@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;
  }

  .header-pulse::after { display: none; }
  .scroll-progress { display: none; }
}