/* ===== 星空赛场 · 共享样式 /assets/site.css ===== */

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, p, figure, ul, ol, dl { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
table { border-collapse: collapse; }

/* ---------- 变量 ---------- */
:root {
  --void: #05070F;
  --nebula: #0E1830;
  --nightsea: #16324A;
  --neon: #7B5CFF;
  --cyan: #2FE0D0;
  --red: #E23A3A;
  --yellow: #F5C518;
  --paper: #F4EFE6;
  --ink: #14161C;
  --dust: #9AA3B8;
  --mist: #C9D2E3;

  --line: rgba(201, 210, 227, .16);
  --line-strong: rgba(201, 210, 227, .32);
  --rail-w: 282px;
  --bar-h: 64px;
  --maxw: 1180px;
  --radius: 14px;
  --radius-sm: 8px;

  --font-display: "Poppins", "Montserrat", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, "Times New Roman", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Noto Sans SC", monospace;

  --shadow-float: 0 24px 60px rgba(0, 0, 0, .55);
  --ease: cubic-bezier(.22, .68, .32, 1);
}

/* ---------- 基底与星空 ---------- */
body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  color: var(--mist);
  background-color: var(--void);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    radial-gradient(1200px 700px at 78% -12%, rgba(123, 92, 255, .30), transparent 62%),
    radial-gradient(900px 620px at 4% 10%, rgba(47, 224, 208, .16), transparent 64%),
    radial-gradient(760px 520px at 46% 112%, rgba(22, 50, 74, .95), transparent 72%),
    linear-gradient(180deg, #05070F 0%, #070C18 44%, #05070F 100%);
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .9;
  background-repeat: no-repeat;
  background-image:
    radial-gradient(1.7px 1.7px at 12% 14%, rgba(255, 255, 255, .9), transparent 60%),
    radial-gradient(1.4px 1.4px at 32% 6%, rgba(201, 210, 227, .8), transparent 60%),
    radial-gradient(1.9px 1.9px at 68% 22%, rgba(47, 224, 208, .75), transparent 60%),
    radial-gradient(1.3px 1.3px at 86% 9%, rgba(255, 255, 255, .75), transparent 60%),
    radial-gradient(1.6px 1.6px at 22% 48%, rgba(255, 255, 255, .6), transparent 60%),
    radial-gradient(1.2px 1.2px at 54% 62%, rgba(123, 92, 255, .85), transparent 60%),
    radial-gradient(1.8px 1.8px at 78% 78%, rgba(255, 255, 255, .7), transparent 60%),
    radial-gradient(1.4px 1.4px at 42% 88%, rgba(47, 224, 208, .6), transparent 60%),
    radial-gradient(1.3px 1.3px at 8% 74%, rgba(255, 255, 255, .55), transparent 60%),
    radial-gradient(1.5px 1.5px at 92% 46%, rgba(255, 255, 255, .62), transparent 60%);
}
::selection { background: var(--neon); color: #fff; }

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

#main-content { display: block; min-height: 58vh; }
#main-content, section[id] { scroll-margin-top: 84px; }

.skip-link {
  position: absolute;
  left: 14px;
  top: -72px;
  z-index: 120;
  padding: 10px 16px;
  border-radius: 0 0 10px 10px;
  background: var(--cyan);
  color: #04121A;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: .06em;
  transition: top .2s var(--ease);
}
.skip-link:focus { top: 0; }

/* ---------- 头部：移动端吸顶栏 + 桌面左侧轨道 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: linear-gradient(180deg, rgba(14, 24, 48, .97), rgba(5, 7, 15, .95));
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}
.bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  min-height: var(--bar-h);
  padding: 10px 18px;
}
.brand-link { display: flex; align-items: center; gap: 12px; color: var(--paper); }
.brand-mark {
  flex: none;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  border: 1px solid rgba(123, 92, 255, .55);
  background: radial-gradient(circle at 30% 25%, rgba(47, 224, 208, .38), rgba(123, 92, 255, .32) 46%, rgba(5, 7, 15, .92));
  color: var(--cyan);
}
.brand-mark svg { width: 22px; height: 22px; }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: .08em;
  color: #fff;
}
.brand-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--dust);
}
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(22, 50, 74, .55);
  color: var(--paper);
  font-size: 13px;
  letter-spacing: .14em;
  cursor: pointer;
  transition: border-color .25s var(--ease), background .25s var(--ease);
}
.nav-toggle:hover { border-color: rgba(47, 224, 208, .6); }
.nav-toggle-bars { position: relative; display: block; width: 18px; height: 12px; }
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  transition: transform .3s var(--ease), top .3s var(--ease), bottom .3s var(--ease);
}
.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }
.site-header[data-open="true"] .nav-toggle-bars::before { top: 5px; transform: rotate(45deg); }
.site-header[data-open="true"] .nav-toggle-bars::after { bottom: 5px; transform: rotate(-45deg); }

.rail { display: none; }
.site-header[data-open="true"] .rail {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 4px 18px 24px;
  max-height: calc(100vh - var(--bar-h));
  overflow-y: auto;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 24, 48, .99), rgba(5, 7, 15, .99));
}
.rail-note {
  font-family: var(--font-serif);
  font-size: 13px;
  line-height: 1.75;
  letter-spacing: .05em;
  color: var(--dust);
  padding-left: 12px;
  border-left: 2px solid var(--neon);
}
.site-nav { display: flex; flex-direction: column; gap: 14px; }
.nav-utility {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 10px;
  padding: 8px 11px;
  border: 1px dashed rgba(245, 197, 24, .44);
  border-radius: var(--radius-sm);
  background: linear-gradient(90deg, rgba(245, 197, 24, .12), transparent 78%);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
}
.nav-utility-key { color: var(--yellow); }
.nav-utility-key::after {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-left: 7px;
  border-radius: 50%;
  background: var(--yellow);
  vertical-align: middle;
  animation: xk-pulse 2.4s infinite;
}
@keyframes xk-pulse {
  0% { box-shadow: 0 0 0 0 rgba(245, 197, 24, .7); }
  70% { box-shadow: 0 0 0 8px rgba(245, 197, 24, 0); }
  100% { box-shadow: 0 0 0 0 rgba(245, 197, 24, 0); }
}
.nav-utility-val { color: var(--cyan); }
.nav-list { display: flex; flex-direction: column; gap: 4px; }
.nav-item { display: block; }
.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 12px;
  border-radius: 10px;
  border: 1px solid transparent;
  color: var(--mist);
  transition: background .25s var(--ease), color .2s var(--ease), transform .25s var(--ease), border-color .25s var(--ease);
}
.nav-index {
  flex: none;
  width: 22px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--dust);
}
.nav-label { font-family: var(--font-serif); font-size: 16px; letter-spacing: .06em; }
.nav-link:hover,
.nav-link:focus-visible {
  background: rgba(123, 92, 255, .16);
  border-color: rgba(123, 92, 255, .45);
  color: #fff;
  transform: translateX(3px);
}
.nav-link:hover .nav-index { color: var(--cyan); }
.nav-link[aria-current="page"] {
  background: linear-gradient(90deg, rgba(47, 224, 208, .18), rgba(123, 92, 255, .10));
  border-color: rgba(47, 224, 208, .5);
  box-shadow: inset 3px 0 0 var(--cyan);
  color: #fff;
}
.nav-link[aria-current="page"] .nav-index { color: var(--yellow); }
.quick-track {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}
.quick-track-title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--dust);
}
.quick-list { display: flex; flex-wrap: wrap; gap: 6px; }
.quick-chip {
  display: inline-flex;
  align-items: center;
  padding: 6px 11px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(22, 50, 74, .5);
  color: var(--mist);
  font-size: 12.5px;
  letter-spacing: .04em;
  transition: background .25s var(--ease), color .2s var(--ease), border-color .25s var(--ease), transform .25s var(--ease);
}
.quick-chip:hover,
.quick-chip:focus-visible {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #04121A;
  transform: translateY(-2px);
}

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 64px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, #070C18 0%, #0E1830 42%, #05070F 100%);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 2px;
  opacity: .85;
  background: linear-gradient(90deg, var(--neon), var(--cyan) 46%, var(--yellow) 72%, var(--red));
}
.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 54px 22px 34px;
  display: grid;
  gap: 34px;
  grid-template-columns: 1fr;
}
.footer-brand { display: flex; flex-direction: column; gap: 10px; }
.footer-brand-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 26px;
  letter-spacing: .1em;
  color: var(--paper);
}
.footer-brand-line {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--cyan);
}
.footer-note {
  font-family: var(--font-serif);
  font-size: 13.5px;
  line-height: 1.95;
  color: var(--dust);
  max-width: 32ch;
}
.footer-coords {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: rgba(154, 163, 184, .7);
}
.footer-cols { display: grid; gap: 26px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
.footer-col { display: flex; flex-direction: column; }
.footer-col-title {
  font-family: var(--font-serif);
  font-size: 14px;
  letter-spacing: .16em;
  color: var(--paper);
  padding-bottom: 10px;
  margin-bottom: 12px;
  border-bottom: 1px dashed var(--line-strong);
}
.footer-links { display: flex; flex-direction: column; gap: 9px; }
.footer-link {
  font-size: 14px;
  color: var(--dust);
  transition: color .2s var(--ease), transform .25s var(--ease);
}
.footer-link:hover,
.footer-link:focus-visible { color: var(--cyan); transform: translateX(3px); }
.footer-base { border-top: 1px solid var(--line); background: rgba(5, 7, 15, .72); }
.footer-base-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 18px 22px 26px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--dust);
}
.footer-legal { color: var(--mist); }
.footer-contact { color: var(--dust); }
.footer-copy { color: rgba(154, 163, 184, .8); }

/* ---------- 布局与文字 ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: 22px; }
.section { padding: clamp(38px, 6vw, 72px) 0; }
.section-head { display: flex; flex-direction: column; gap: 12px; margin-bottom: 26px; }
.section-kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--cyan);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.section-kicker::before { content: ""; width: 26px; height: 2px; background: var(--neon); }
.section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 4.4vw, 44px);
  line-height: 1.16;
  letter-spacing: .01em;
  color: #fff;
}
.section-desc { color: var(--dust); max-width: 58ch; }
.stack { display: flex; flex-direction: column; gap: 16px; }
.row { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.prose { max-width: 36em; font-size: 17px; line-height: 1.78; color: var(--mist); }
.prose p + p { margin-top: 14px; }
.lede { font-size: clamp(17px, 2.2vw, 20px); line-height: 1.85; color: var(--mist); }
.surface-paper {
  border-radius: var(--radius);
  padding: clamp(20px, 3.4vw, 32px);
  background: var(--paper);
  color: var(--ink);
  box-shadow: var(--shadow-float);
}
.surface-paper .section-title,
.surface-paper .lede,
.surface-paper .prose { color: var(--ink); }
.surface-paper .section-kicker { color: #6A3BD6; }
.surface-paper .section-desc { color: #4A4F5C; }

/* ---------- 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14.5px;
  letter-spacing: .06em;
  cursor: pointer;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s var(--ease), color .2s var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn--neon { background: linear-gradient(120deg, var(--neon), #5A3BFF); color: #fff; box-shadow: 0 12px 34px rgba(123, 92, 255, .42); }
.btn--cyan { background: var(--cyan); color: #04121A; box-shadow: 0 12px 34px rgba(47, 224, 208, .28); }
.btn--ghost { background: rgba(22, 50, 74, .4); border-color: var(--line-strong); color: var(--paper); }
.btn--ghost:hover { border-color: rgba(47, 224, 208, .6); color: var(--cyan); }
.btn--paper { background: var(--paper); color: var(--ink); }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(22, 50, 74, .45);
  color: var(--mist);
  font-size: 12.5px;
  letter-spacing: .05em;
}
.chip--neon { border-color: rgba(123, 92, 255, .6); color: #CFC3FF; background: rgba(123, 92, 255, .16); }
.chip--cyan { border-color: rgba(47, 224, 208, .55); color: var(--cyan); background: rgba(47, 224, 208, .12); }
.chip--red { border-color: rgba(226, 58, 58, .6); color: #FF9A9A; background: rgba(226, 58, 58, .14); }
.chip--yellow { border-color: rgba(245, 197, 24, .6); color: var(--yellow); background: rgba(245, 197, 24, .12); }

.flag-dot { display: inline-block; width: 10px; height: 16px; border-radius: 2px; background: var(--yellow); }
.flag-dot--red { background: var(--red); }
.flag-dot--yellow { background: var(--yellow); }

/* ---------- 卡片 / 数据 / 标签牌 ---------- */
.card {
  position: relative;
  overflow: hidden;
  padding: 22px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(14, 24, 48, .94), rgba(5, 7, 15, .88));
  transition: transform .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease);
}
.card::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(420px 200px at 100% 0, rgba(123, 92, 255, .18), transparent 70%);
}
.card:hover { transform: translateY(-4px); border-color: rgba(47, 224, 208, .42); box-shadow: 0 22px 54px rgba(0, 0, 0, .5); }
.card--paper { background: var(--paper); border-color: rgba(20, 22, 28, .16); color: var(--ink); }
.card--paper::after { background: radial-gradient(380px 200px at 100% 0, rgba(47, 224, 208, .24), transparent 72%); }
.card--accent { border-color: rgba(47, 224, 208, .48); box-shadow: 0 20px 50px rgba(47, 224, 208, .14); }

.stat { display: flex; flex-direction: column; gap: 6px; }
.stat-value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1;
  letter-spacing: -.01em;
  color: #fff;
}
.stat-label { font-family: var(--font-mono); font-size: 12px; letter-spacing: .16em; color: var(--dust); }
.stat-unit { margin-left: 6px; font-size: 14px; color: var(--cyan); }

.label-tag {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  padding: 7px 12px;
  border-radius: 4px;
  border: 1px solid var(--line-strong);
  background: rgba(244, 239, 230, .06);
}
.label-tag-num { font-family: var(--font-mono); font-size: 11px; letter-spacing: .16em; color: var(--yellow); }
.label-tag-name { font-family: var(--font-serif); font-size: 13px; letter-spacing: .12em; color: var(--paper); }
.label-tag--paper { background: var(--paper); border-color: rgba(20, 22, 28, .2); }
.label-tag--paper .label-tag-name { color: var(--ink); }
.label-tag--paper .label-tag-num { color: #B25A0A; }

.data-table { width: 100%; font-family: var(--font-mono); font-size: 13.5px; }
.data-table th,
.data-table td { padding: 11px 12px; text-align: left; border-bottom: 1px solid var(--line); }
.data-table th {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 12.5px;
  letter-spacing: .12em;
  color: var(--dust);
}
.data-table tbody tr { transition: background .2s var(--ease); }
.data-table tbody tr:hover { background: rgba(47, 224, 208, .07); }

/* ---------- 网格 ---------- */
.grid { display: grid; gap: 18px; }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(172px, 1fr)); }

/* ---------- 图片容器 ---------- */
.media-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: radial-gradient(120% 90% at 20% 8%, #16324A 0%, #0E1830 45%, #05070F 100%);
}
.media-frame > img,
.media-frame > svg,
.media-frame > video { width: 100%; height: 100%; object-fit: cover; }
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(5, 7, 15, .0) 40%, rgba(5, 7, 15, .62) 100%);
}
.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame__caption {
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 14px;
  z-index: 2;
  padding: 8px 12px;
  border-left: 2px solid var(--cyan);
  border-radius: 0 6px 6px 0;
  background: rgba(5, 7, 15, .74);
  font-family: var(--font-serif);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--paper);
}
.media-grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }

/* ---------- 面包屑 ---------- */
.breadcrumb { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .14em; color: var(--dust); }
.breadcrumb-list { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.breadcrumb-item { display: inline-flex; align-items: center; }
.breadcrumb-item + .breadcrumb-item::before { content: "/"; margin-right: 8px; color: rgba(201, 210, 227, .4); }
.breadcrumb-link { color: var(--dust); transition: color .2s var(--ease); }
.breadcrumb-link:hover,
.breadcrumb-link:focus-visible { color: var(--cyan); }

/* ---------- 标签切换 ---------- */
.tabs {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
  max-width: 100%;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(14, 24, 48, .7);
}
.tab {
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--dust);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 13.5px;
  letter-spacing: .06em;
  cursor: pointer;
  transition: color .2s var(--ease), background .25s var(--ease);
}
.tab:hover { color: var(--paper); }
.tab[aria-selected="true"] {
  background: linear-gradient(120deg, rgba(123, 92, 255, .92), rgba(47, 224, 208, .88));
  color: #04121A;
}
.tab-panel { padding-top: 20px; }
.tab-panel[hidden] { display: none; }

/* ---------- 动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .55s var(--ease), transform .55s var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}
[data-reveal].is-visible { opacity: 1; transform: none; }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
  background: linear-gradient(90deg, var(--neon), var(--cyan));
  box-shadow: 0 0 12px rgba(47, 224, 208, .6);
}
.to-top {
  position: fixed;
  right: 18px;
  bottom: 22px;
  z-index: 150;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 15px;
  border-radius: 999px;
  border: 1px solid rgba(47, 224, 208, .5);
  background: rgba(5, 7, 15, .88);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .3s var(--ease), transform .3s var(--ease), visibility .3s var(--ease);
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--cyan); color: #04121A; }

/* ---------- 平板 ---------- */
@media (min-width: 760px) {
  .footer-inner { grid-template-columns: 1fr 1.7fr; }
  body { font-size: 17px; }
}

/* ---------- 桌面：品牌轨道 ---------- */
@media (min-width: 1080px) {
  body { padding-left: var(--rail-w); }
  #main-content, section[id] { scroll-margin-top: 24px; }
  .site-header {
    position: fixed;
    inset: 0 auto 0 0;
    width: var(--rail-w);
    display: flex;
    flex-direction: column;
    border-bottom: 0;
    border-right: 1px solid var(--line);
    background: linear-gradient(180deg, #0B1426 0%, #080D1A 56%, #05070F 100%);
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }
  .site-header::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 3px;
    height: 100%;
    opacity: .5;
    pointer-events: none;
    background: repeating-linear-gradient(180deg, rgba(47, 224, 208, .55) 0 1px, transparent 1px 14px);
  }
  .bar {
    min-height: 0;
    padding: 24px 22px 18px;
    border-bottom: 1px solid var(--line);
  }
  .nav-toggle { display: none; }
  .rail {
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 20px;
    padding: 22px 18px 28px;
    overflow-y: auto;
  }
  .scroll-progress { left: var(--rail-w); width: calc(100% - var(--rail-w)); }
  .footer-inner { padding-top: 62px; }
}

/* ---------- 降低动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .to-top { transform: none; }
}