/* ==========================================================================
   UC赛场 — 共享站点样式 /assets/site.css
   语言：深空蓝画布 · 电子青数据 · 活力橙行动 · 斜切赛场节奏
   ========================================================================== */

/* 1. 设计令牌
   ========================================================================== */
:root {
  --ink-900: #061224;
  --ink-800: #0B1F3A;
  --ink-700: #1B3A5C;
  --cyan: #00E5FF;
  --cyan-soft: #7CF0FF;
  --orange: #FF6B35;
  --paper: #F3EDE2;
  --mist: #E6EDF5;
  --steel: #1B3A5C;
  --green: #3DDC97;
  --amber: #FFC857;

  --font-display: Impact, Haettenschweiler, "Arial Narrow Bold", "Noto Sans SC", "PingFang SC", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  --font-data: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --fs-body: clamp(15px, 1.02vw, 17px);
  --fs-h1: clamp(44px, 8vw, 112px);
  --fs-h2: clamp(28px, 4vw, 56px);
  --fs-h3: clamp(20px, 2.4vw, 30px);
  --fs-data: clamp(40px, 7vw, 96px);

  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --dur: 200ms;

  --shell-max: 1320px;
  --gutter: clamp(16px, 4vw, 48px);
  --radius: 10px;

  --line-soft: 1px solid rgba(27, 58, 92, 0.9);
  --line-cyan: 1px solid rgba(0, 229, 255, 0.32);

  --rail-h: 38px;
  --deck-h: 72px;
  --bar-h: 64px;
}

/* 2. Reset 与基础排版
   ========================================================================== */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background-color: var(--ink-800);
  background-image:
    radial-gradient(120% 80% at 88% -10%, rgba(0, 229, 255, 0.10), transparent 58%),
    radial-gradient(90% 70% at -10% 30%, rgba(255, 107, 53, 0.07), transparent 62%);
  background-repeat: no-repeat;
  color: var(--mist);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
input, textarea, select { font: inherit; }

h1, h2, h3 { line-height: 1.12; font-weight: 800; letter-spacing: -0.01em; }

::selection { background: var(--cyan); color: var(--ink-900); }

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

#main-content {
  display: block;
  scroll-margin-top: calc(var(--deck-h) + 16px);
}

/* 3. 容器与网格
   ========================================================================== */
.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid { display: grid; gap: clamp(16px, 2.4vw, 32px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

.section { position: relative; padding-block: clamp(52px, 7vw, 110px); }
.section--paper { background: var(--paper); color: var(--ink-800); }
.section--paper h2,
.section--paper h3 { color: var(--ink-800); }
.section--paper .prose p { color: rgba(11, 31, 58, 0.78); }
.section--paper .section-label { color: #0A6E86; }
.section--paper .breadcrumb { color: rgba(11, 31, 58, 0.55); }
.section--paper .breadcrumb a { color: #0A6E86; }

.grid-texture { position: relative; }
.grid-texture::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(124, 240, 255, 0.07) 0 1px, transparent 1px 64px),
    repeating-linear-gradient(0deg, rgba(124, 240, 255, 0.07) 0 1px, transparent 1px 64px);
  -webkit-mask-image: linear-gradient(180deg, #000, transparent 88%);
  mask-image: linear-gradient(180deg, #000, transparent 88%);
}

/* 4. 跳转链接
   ========================================================================== */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 999;
  transform: translateY(-240%);
  padding: 12px 22px;
  border-radius: 6px;
  background: var(--cyan);
  color: var(--ink-900);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); outline-offset: 4px; }

/* 5. 页头 — 上层信息轨
   ========================================================================== */
.site-header { position: relative; z-index: 90; }

.header-rail {
  background: var(--ink-900);
  border-bottom: 1px solid rgba(27, 58, 92, 0.85);
}

.header-rail__inner {
  display: flex;
  align-items: center;
  gap: clamp(14px, 3vw, 32px);
  min-height: var(--rail-h);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(230, 237, 245, 0.6);
}

.header-rail__descriptor {
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--mist);
  font-weight: 500;
  white-space: nowrap;
}

.header-rail__hours { margin-left: auto; white-space: nowrap; }

.header-rail__mail {
  font-family: var(--font-data);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--cyan-soft);
  white-space: nowrap;
}

.signal-dot {
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(61, 220, 151, 0.18);
  animation: signal-pulse 2.8s var(--ease) infinite;
}

@keyframes signal-pulse {
  0%, 100% { box-shadow: 0 0 0 3px rgba(61, 220, 151, 0.18); }
  50% { box-shadow: 0 0 0 7px rgba(61, 220, 151, 0.04); }
}

/* 6. 页头 — 吸顶玻璃导航
   ========================================================================== */
.header-deck {
  position: sticky;
  top: 0;
  z-index: 90;
  background: linear-gradient(180deg, rgba(11, 31, 58, 0.94), rgba(6, 18, 36, 0.9));
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid rgba(0, 229, 255, 0.22);
  box-shadow: 0 20px 44px -30px rgba(0, 0, 0, 0.95);
}

.header-deck__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(10px, 2vw, 28px);
  min-height: var(--deck-h);
}

.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  transition: transform 140ms linear;
  pointer-events: none;
}

/* 7. 品牌锁定组
   ========================================================================== */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: none;
  transition: transform var(--dur) var(--ease);
}
.brand:hover { transform: translateY(-1px); }

.brand__mark {
  position: relative;
  flex: none;
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: linear-gradient(150deg, var(--cyan) 0%, #0E6F8C 56%, var(--orange) 100%);
  transform: skewX(-8deg);
  box-shadow: 0 0 0 1px rgba(0, 229, 255, 0.35), 0 8px 20px -8px rgba(0, 229, 255, 0.5);
}
.brand__mark::before,
.brand__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 19px;
  height: 2px;
  background: var(--ink-900);
  transform: translate(-50%, -50%) rotate(-45deg);
}
.brand__mark::after { width: 10px; opacity: 0.6; }

.brand__text { display: flex; flex-direction: column; line-height: 1; }

.brand__name {
  font-family: var(--font-display);
  font-size: 22px;
  letter-spacing: 0.03em;
  color: var(--paper);
  transform: skewX(-6deg);
}

.brand__sub {
  margin-top: 5px;
  font-family: var(--font-data);
  font-size: 9px;
  letter-spacing: 0.28em;
  color: var(--cyan-soft);
  opacity: 0.78;
}

.brand--footer .brand__name { font-size: 26px; }

/* 8. 主导航
   ========================================================================== */
.nav {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.4vw, 16px);
  min-width: 0;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 4px;
  border: var(--line-soft);
  border-radius: 999px;
  background: rgba(230, 237, 245, 0.05);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.nav__item { display: flex; }

.nav__link {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 9px 13px;
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--mist);
  white-space: nowrap;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav__link:hover { background: rgba(0, 229, 255, 0.14); color: var(--cyan-soft); }
.nav__link[aria-current="page"] {
  background: var(--cyan);
  color: var(--ink-900);
  font-weight: 700;
}
.nav__link[aria-current="page"]:hover { background: var(--cyan-soft); color: var(--ink-900); }

.nav__index {
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.08em;
  opacity: 0.62;
}

.nav__quick {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: none;
}

/* 9. 移动菜单按钮
   ========================================================================== */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: var(--line-cyan);
  border-radius: 8px;
  color: var(--cyan-soft);
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.16em;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-toggle:hover { background: rgba(0, 229, 255, 0.14); color: var(--cyan); }

.nav-toggle__glyph {
  position: relative;
  display: block;
  width: 18px;
  height: 12px;
}
.nav-toggle__glyph span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease), width var(--dur) var(--ease);
}
.nav-toggle__glyph span:nth-child(1) { top: 0; }
.nav-toggle__glyph span:nth-child(2) { top: 5px; width: 70%; }
.nav-toggle__glyph span:nth-child(3) { top: 10px; }

.site-header[data-open] .nav-toggle__glyph span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.site-header[data-open] .nav-toggle__glyph span:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle__glyph span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* 10. 按钮系统
   ========================================================================== */
.btn {
  --btn-bg: var(--orange);
  --btn-fg: var(--ink-900);
  position: relative;
  isolation: isolate;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 28px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
  color: var(--btn-fg);
  white-space: nowrap;
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}
.btn::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--btn-bg);
  clip-path: polygon(13px 0, 100% 0, calc(100% - 13px) 100%, 0 100%);
  transition: background-color var(--dur) var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn--heat { --btn-bg: var(--orange); --btn-fg: var(--ink-900); }
.btn--heat:hover::before { background: #FF8557; }

.btn--ghost {
  --btn-bg: rgba(0, 229, 255, 0.10);
  --btn-fg: var(--cyan-soft);
}
.btn--ghost::before { box-shadow: inset 0 0 0 1px rgba(0, 229, 255, 0.45); }
.btn--ghost:hover { color: var(--ink-900); }
.btn--ghost:hover::before { background: var(--cyan); }

.btn--sm { padding: 10px 18px; font-size: 12.5px; }

/* 11. 通用内容组件
   ========================================================================== */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
}
.section-label::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--orange);
  transform: skewX(-24deg);
}

.display {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: 400;
  line-height: 0.92;
  letter-spacing: -0.01em;
  transform: skewX(-6deg);
  transform-origin: 0 100%;
}

.prose { max-width: 34em; }
.prose p { margin-bottom: 1.1em; color: rgba(230, 237, 245, 0.82); }
.prose p:last-child { margin-bottom: 0; }
.prose h2, .prose h3 { margin: 1.4em 0 0.55em; font-size: var(--fs-h3); }
.prose ul { margin: 0 0 1.1em; }
.prose li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 0.5em;
  color: rgba(230, 237, 245, 0.82);
}
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 7px;
  height: 2px;
  background: var(--orange);
  transform: skewX(-24deg);
}
.prose a {
  color: var(--cyan-soft);
  border-bottom: 1px solid rgba(0, 229, 255, 0.42);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.prose a:hover { color: var(--cyan); border-color: var(--cyan); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 9px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(230, 237, 245, 0.55);
}
.breadcrumb a { color: var(--cyan-soft); transition: color var(--dur) var(--ease); }
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb__sep { color: rgba(0, 229, 255, 0.4); }

.glass-panel {
  padding: clamp(18px, 2.6vw, 32px);
  border: var(--line-cyan);
  border-radius: var(--radius);
  background: rgba(230, 237, 245, 0.06);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.data-number {
  font-family: var(--font-data);
  font-size: var(--fs-data);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--cyan);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid rgba(0, 229, 255, 0.3);
  border-radius: 3px;
  background: rgba(0, 229, 255, 0.14);
  color: var(--cyan-soft);
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.5;
}
.tag--amber {
  border-color: rgba(255, 200, 87, 0.38);
  background: rgba(255, 200, 87, 0.14);
  color: var(--amber);
}
.tag--green {
  border-color: rgba(61, 220, 151, 0.38);
  background: rgba(61, 220, 151, 0.14);
  color: var(--green);
}
.tag--heat {
  border-color: rgba(255, 107, 53, 0.42);
  background: rgba(255, 107, 53, 0.16);
  color: #FFB79B;
}

.callout {
  padding: 16px 20px;
  border-left: 3px solid var(--orange);
  border-radius: 0 8px 8px 0;
  background: rgba(255, 107, 53, 0.08);
}
.callout p { color: rgba(230, 237, 245, 0.86); }

/* 12. 图片容器基础（页面阶段放置图片使用）
   ========================================================================== */
.media-frame {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 10;
  border-radius: var(--radius);
  background: linear-gradient(150deg, #0D2747, #061224);
}
.media-frame > img,
.media-frame > svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 320ms var(--ease);
}
.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, rgba(0, 229, 255, 0.10) 0 1px, transparent 1px 48px),
    repeating-linear-gradient(0deg, rgba(0, 229, 255, 0.10) 0 1px, transparent 1px 48px);
  opacity: 0.7;
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(150deg, rgba(11, 31, 58, 0.6), rgba(0, 229, 255, 0.16) 55%, rgba(255, 107, 53, 0.24));
  mix-blend-mode: screen;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

/* 13. 页脚
   ========================================================================== */
.site-footer {
  position: relative;
  margin-top: clamp(52px, 8vw, 110px);
  padding: calc(3.2vw + 56px) 0 32px;
  color: var(--mist);
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(0, 229, 255, 0.16), transparent 58%),
    radial-gradient(90% 70% at 0% 110%, rgba(255, 107, 53, 0.12), transparent 62%),
    var(--ink-900);
  clip-path: polygon(0 3.2vw, 100% 0, 100% 100%, 0 100%);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(124, 240, 255, 0.06) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, rgba(124, 240, 255, 0.06) 0 1px, transparent 1px 72px);
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 72%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 72%);
}

.footer__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.4fr 0.9fr 1.2fr;
  gap: clamp(24px, 4vw, 64px);
  padding-bottom: clamp(28px, 4vw, 48px);
  border-bottom: 1px solid rgba(27, 58, 92, 0.9);
}

.footer__brand { display: flex; flex-direction: column; align-items: flex-start; }

.footer__line {
  max-width: 26em;
  margin-top: 18px;
  font-size: 15px;
  color: rgba(230, 237, 245, 0.72);
}

.footer__cta { margin-top: 24px; }

.footer__title {
  margin-bottom: 16px;
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer__links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 20px;
}
.footer__links a {
  position: relative;
  display: inline-block;
  padding-left: 0;
  font-size: 14px;
  color: rgba(230, 237, 245, 0.78);
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.footer__links a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 2px;
  background: var(--orange);
  transform: translateY(-50%) skewX(-24deg);
  transition: width var(--dur) var(--ease);
}
.footer__links a:hover { color: var(--cyan-soft); padding-left: 16px; }
.footer__links a:hover::before { width: 10px; }
.footer__links a[aria-current="page"] { color: var(--cyan); font-weight: 600; }

.footer__contact-list li {
  position: relative;
  padding-left: 15px;
  margin-bottom: 11px;
  font-size: 14px;
  line-height: 1.65;
  color: rgba(230, 237, 245, 0.74);
}
.footer__contact-list li:last-child { margin-bottom: 0; }
.footer__contact-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  transform: skewX(-24deg);
}

.footer__watermark {
  position: relative;
  margin: clamp(24px, 4vw, 44px) auto clamp(16px, 2vw, 26px);
  font-family: var(--font-display);
  font-size: clamp(44px, 11vw, 164px);
  line-height: 0.82;
  letter-spacing: -0.02em;
  white-space: nowrap;
  overflow: hidden;
  color: rgba(124, 240, 255, 0.07);
  transform: skewX(-6deg);
  transform-origin: 0 100%;
  user-select: none;
}
@supports (-webkit-text-stroke: 1px red) {
  .footer__watermark {
    color: transparent;
    -webkit-text-stroke: 1px rgba(124, 240, 255, 0.16);
  }
}

.footer__base {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  padding-top: 24px;
  border-top: 1px solid rgba(27, 58, 92, 0.7);
  font-family: var(--font-data);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: rgba(230, 237, 245, 0.5);
}
.footer__note { margin-left: auto; }

/* 14. 响应式 — 平板与移动
   ========================================================================== */
@media (max-width: 1080px) {
  .header-rail { display: none; }

  body {
    padding-bottom: calc(var(--bar-h) + env(safe-area-inset-bottom, 0px));
  }

  .header-deck {
    position: fixed;
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    border-bottom: 0;
    border-top: 1px solid rgba(0, 229, 255, 0.28);
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }

  .header-deck__inner { min-height: var(--bar-h); }

  .scroll-meter { top: -1px; bottom: auto; }

  .brand__sub { display: none; }
  .brand__mark { width: 30px; height: 30px; border-radius: 8px; }
  .brand__name { font-size: 19px; }

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

  .nav {
    position: absolute;
    left: 12px;
    right: 12px;
    bottom: calc(100% + 12px);
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    max-height: 0;
    padding: 0 16px;
    overflow: hidden;
    background: rgba(6, 18, 36, 0.97);
    border: 1px solid transparent;
    border-radius: 16px;
    box-shadow: 0 28px 64px -28px rgba(0, 0, 0, 0.95);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition:
      opacity var(--dur) var(--ease),
      transform var(--dur) var(--ease),
      max-height var(--dur) var(--ease),
      padding var(--dur) var(--ease),
      border-color var(--dur) var(--ease),
      visibility var(--dur) var(--ease);
  }

  .site-header[data-open] .nav,
  .nav[data-open] {
    max-height: min(72vh, 540px);
    padding: 16px;
    overflow-y: auto;
    border-color: rgba(0, 229, 255, 0.28);
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: none;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }

  .nav__link {
    padding: 13px 14px;
    border-radius: 10px;
    font-size: 15px;
  }

  .nav__quick {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding-top: 14px;
    border-top: 1px solid rgba(27, 58, 92, 0.9);
  }
  .nav__quick .btn { width: 100%; }

  .site-footer {
    clip-path: polygon(0 2.4vw, 100% 0, 100% 100%, 0 100%);
    padding-top: calc(2.4vw + 48px);
  }

  .footer__inner { grid-template-columns: 1fr; gap: 34px; }
  .footer__note { margin-left: 0; flex-basis: 100%; }
}

@media (max-width: 820px) {
  .grid--2,
  .grid--3 { grid-template-columns: 1fr; }
  .footer__links { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 560px) {
  :root { --deck-h: 64px; --bar-h: 60px; }
  .nav__index { display: none; }
  .brand { gap: 9px; }
  .footer__links { grid-template-columns: 1fr; }
  .footer__base { font-size: 11px; gap: 6px 18px; }
  .btn { padding: 12px 22px; font-size: 13px; }
  .btn--sm { padding: 10px 16px; font-size: 12px; }
}

/* 15. 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;
    transition-delay: 0ms !important;
  }
  .btn:hover,
  .brand:hover { transform: none; }
  .media-frame > img,
  .media-frame > svg { transition: none; }
}