/* ============================================================
   万博游艺 · 共享样式表 /assets/site.css
   数字档案室 + 夜间游艺厅：深墨蓝底、暗金描边、霓虹青操作色
   ============================================================ */

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

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

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, blockquote, dl, dd, hr {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

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

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

table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 主色 */
  --ink: #0B1A2B;
  --ink-2: #13273D;
  --ink-3: #1B3550;
  --ink-deep: #071322;

  /* 强调色 */
  --gold: #C9A227;
  --gold-soft: #E3C871;
  --gold-line: rgba(201, 162, 39, .42);
  --gold-wash: rgba(201, 162, 39, .10);
  --cyan: #3FE0CE;
  --cyan-dim: rgba(63, 224, 206, .42);
  --coral: #FF6B4A;
  --coral-dim: rgba(255, 107, 74, .45);

  /* 文本 */
  --paper: #F2EDE4;
  --paper-2: #C6D2DF;
  --muted: #8B9AAB;
  --rock: #6E7A88;

  /* 12 大类低饱和色块 */
  --cat-1: #4A5A6B;
  --cat-2: #5F7F63;
  --cat-3: #B5704F;
  --cat-4: #7C6A93;
  --cat-5: #4E7E8C;
  --cat-6: #8C7B4E;
  --cat-7: #8C5F6B;
  --cat-8: #5A6E8C;
  --cat-9: #6E8C7A;
  --cat-10: #9A7B5A;
  --cat-11: #6B6F8C;
  --cat-12: #7E8C58;

  /* 排版 */
  --font-display: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", "IBM Plex Mono", Menlo, Consolas, "Courier New", monospace;

  /* 布局 */
  --maxw: 1240px;
  --gutter: clamp(16px, 4vw, 40px);
  --rail: 240px;
  --radius: 4px;
  --header-h-compact: 70px;
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--ink);
  background-image:
    radial-gradient(1100px 560px at 84% -10%, rgba(63, 224, 206, .08), transparent 62%),
    radial-gradient(900px 520px at 2% 6%, rgba(201, 162, 39, .09), transparent 58%),
    repeating-linear-gradient(0deg, rgba(255, 255, 255, .017) 0 1px, transparent 1px 68px);
  background-repeat: no-repeat, no-repeat, repeat;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: .01em;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -.01em;
  color: var(--paper);
}

p { max-width: 48em; }

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

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

#main-content { scroll-margin-top: 96px; }

/* ---------- 4. 工具类 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.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;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -120px;
  z-index: 200;
  padding: 10px 18px;
  background: linear-gradient(150deg, #E0C05A, #B08C1E);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  border-radius: 0 0 3px 3px;
  transition: top .22s ease;
}
.skip-link:focus { top: 0; }

.mono { font-family: var(--font-mono); letter-spacing: .1em; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--gold);
  text-transform: uppercase;
}

.rule-gold {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--gold-line), transparent);
}

.stack {
  display: flex;
  flex-direction: column;
  gap: clamp(18px, 2.4vw, 28px);
}

/* ---------- 5. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background-image: linear-gradient(180deg, rgba(11, 26, 43, .92), rgba(11, 26, 43, .58) 62%, rgba(11, 26, 43, 0));
  background-color: transparent;
  border-bottom: 1px solid transparent;
  transition: border-color .32s ease, box-shadow .32s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, #0F2237, #0B1A2B 78%, #0B1A2B);
  border-bottom: 1px solid var(--gold-line);
  opacity: 0;
  pointer-events: none;
  transition: opacity .32s ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--gold-line);
  box-shadow: 0 22px 48px -38px #000;
}
.site-header.is-scrolled::before { opacity: 1; }

.header-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  overflow: hidden;
  background: rgba(255, 255, 255, .05);
}
.header-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--gold), var(--cyan));
  box-shadow: 0 0 14px var(--cyan-dim);
}

.header-inner {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px 0 8px;
  transition: padding .3s ease;
}

.site-header.is-scrolled .header-top { padding: 8px 0 4px; }

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.brand__mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 38px;
  height: 38px;
  border: 1px solid var(--gold-line);
  border-radius: 3px;
  background: linear-gradient(160deg, rgba(201, 162, 39, .24), rgba(19, 39, 61, .7));
  box-shadow: inset 0 0 18px rgba(201, 162, 39, .2);
  color: var(--gold-soft);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 19px;
  line-height: 1;
}
.brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}
.brand__name {
  font-family: var(--font-display);
  font-size: clamp(18px, 1.8vw, 22px);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: .06em;
  color: var(--paper);
}
.brand__meta {
  max-height: 20px;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  line-height: 1.5;
  color: var(--muted);
  white-space: nowrap;
  transition: max-height .3s ease, opacity .3s ease;
}
.site-header.is-scrolled .brand__meta {
  max-height: 0;
  opacity: 0;
}

/* 工具入口 */
.utility-list {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 0 0 auto;
}
.utility-link {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--paper-2);
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}
.utility-link:hover,
.utility-link:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan-dim);
  background: rgba(63, 224, 206, .07);
}

/* 导航行 */
.nav-row {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 0 0 12px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  flex: 1 1 auto;
  min-width: 0;
}

.site-nav__list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 2px;
}

.site-nav__item { display: block; }

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 3px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .02em;
  color: var(--paper-2);
  transition: color .2s ease, background-color .2s ease;
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 2px;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .3s ease, background-color .3s ease;
}
.site-nav__link:hover {
  color: var(--paper);
  background: rgba(255, 255, 255, .05);
}
.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] { color: var(--gold-soft); }
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--cyan);
}

.site-nav__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .1em;
  color: var(--rock);
}
.site-nav__link[aria-current="page"] .site-nav__idx { color: var(--cyan); }

.site-nav__foot {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}

/* 徽章 */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .06em;
  white-space: nowrap;
  transition: transform .2s ease, box-shadow .25s ease, background-color .25s ease, color .25s ease;
}
.badge--gold {
  background: linear-gradient(150deg, #DDB845, #A8841B);
  color: #0B1A2B;
  font-weight: 700;
  box-shadow: 0 0 0 1px rgba(224, 197, 106, .55), 0 12px 24px -16px rgba(201, 162, 39, .95);
}
.badge--coral {
  border: 1px solid var(--coral-dim);
  background: rgba(255, 107, 74, .08);
  color: var(--coral);
}
.badge__tag {
  padding: 1px 5px;
  border-radius: 2px;
  background: var(--coral);
  color: #180D08;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: .04em;
}
.badge:hover { transform: translateY(-1px); }

/* 移动导航按钮（桌面隐藏） */
.nav-toggle { display: none; }

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 8vw, 120px);
  padding: clamp(48px, 6vw, 80px) 0 28px;
  background: linear-gradient(180deg, rgba(19, 39, 61, .5), var(--ink-deep) 46%);
  border-top: 1px solid var(--gold-line);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: min(340px, 62%);
  height: 2px;
  background: linear-gradient(90deg, var(--gold), rgba(63, 224, 206, .6), transparent);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: clamp(24px, 3vw, 44px);
}

.footer-brand__name {
  font-family: var(--font-display);
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 900;
  letter-spacing: .06em;
  color: var(--paper);
}
.footer-brand__desc {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 30em;
}
.footer-stamp {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
  padding: 8px 12px;
  border: 1px dashed var(--gold-line);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--gold-soft);
}
.footer-stamp__badge {
  padding: 1px 6px;
  border-radius: 2px;
  background: var(--gold-wash);
  border: 1px solid var(--gold-line);
  font-weight: 700;
}
.footer-stamp__text { letter-spacing: .1em; }

.footer-col__title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .18em;
  color: var(--gold);
}
.footer-list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}
.footer-link {
  display: inline-block;
  font-size: 14px;
  color: var(--paper-2);
  transition: color .2s ease, padding-left .2s ease;
}
.footer-link:hover,
.footer-link:focus-visible {
  color: var(--cyan);
  padding-left: 6px;
}

.footer-contact {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: clamp(32px, 4vw, 52px);
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, .08);
}
.footer-contact__row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}
.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--rock);
}
.footer-contact__value {
  font-size: 14px;
  line-height: 1.7;
  color: var(--paper);
  word-break: break-word;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 24px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, .08);
}
.footer-copy {
  font-size: 13px;
  color: var(--muted);
  max-width: none;
}
.footer-legal-list {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}
.footer-legal-link {
  font-size: 13px;
  color: var(--paper-2);
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}
.footer-legal-link:hover,
.footer-legal-link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan-dim);
}
.footer-icp {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--rock);
  max-width: none;
}

/* ---------- 7. 布局骨架 ---------- */
.layout-split {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr);
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}
.rail {
  position: sticky;
  top: calc(var(--header-h-compact) + 20px);
  align-self: start;
}

.page-head {
  padding: clamp(40px, 6vw, 80px) 0 clamp(20px, 3vw, 36px);
}
.page-head__title {
  font-size: clamp(32px, 5vw, 64px);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -.02em;
}
.page-head__lead {
  margin-top: 18px;
  max-width: 38em;
  font-size: 17px;
  color: var(--paper-2);
}

/* ---------- 8. 章节 ---------- */
.section { padding: clamp(48px, 6.5vw, 96px) 0; }
.section:first-child { padding-top: clamp(28px, 4vw, 56px); }

.section__head {
  display: flex;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 12px 16px;
  margin-bottom: clamp(24px, 3vw, 40px);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--gold-line);
}
.section__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--gold);
  line-height: 1.6;
}
.section__title {
  font-size: clamp(23px, 3.2vw, 40px);
  font-weight: 900;
  line-height: 1.15;
}
.section__lead {
  margin-left: auto;
  max-width: 34em;
  font-size: 15px;
  color: var(--muted);
}

/* ---------- 9. 面板与卡片 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 2.6vw, 32px);
  border: 1px solid rgba(201, 162, 39, .22);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(19, 39, 61, .84), rgba(11, 26, 43, .72));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .04);
}
.panel--glass {
  background: rgba(19, 39, 61, .55);
  border-color: rgba(255, 255, 255, .1);
  -webkit-backdrop-filter: blur(12px) saturate(130%);
  backdrop-filter: blur(12px) saturate(130%);
}
.panel--solid {
  background: var(--ink-2);
  border-color: rgba(255, 255, 255, .09);
  box-shadow: 0 26px 60px -46px #000;
}
.panel--accent { border-left: 2px solid var(--cyan); }

.card {
  position: relative;
  overflow: hidden;
  padding: 22px 22px 22px 26px;
  border: 1px solid rgba(255, 255, 255, .07);
  border-radius: var(--radius);
  background: linear-gradient(165deg, rgba(19, 39, 61, .9), rgba(11, 26, 43, .88));
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}
.card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--cat, var(--rock));
}
.card:hover {
  transform: translateY(-3px);
  border-color: var(--gold-line);
  box-shadow: 0 28px 54px -38px #000;
}
.card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
}
.card__title {
  margin: 8px 0 6px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}
.card__text {
  font-size: 15px;
  color: var(--paper-2);
  max-width: 42em;
}
.card__tag { margin-top: 14px; }

.chip-cat {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--cat, var(--rock));
  flex: 0 0 auto;
}

/* 12 大类色块 */
[data-cat="1"] { --cat: var(--cat-1); }
[data-cat="2"] { --cat: var(--cat-2); }
[data-cat="3"] { --cat: var(--cat-3); }
[data-cat="4"] { --cat: var(--cat-4); }
[data-cat="5"] { --cat: var(--cat-5); }
[data-cat="6"] { --cat: var(--cat-6); }
[data-cat="7"] { --cat: var(--cat-7); }
[data-cat="8"] { --cat: var(--cat-8); }
[data-cat="9"] { --cat: var(--cat-9); }
[data-cat="10"] { --cat: var(--cat-10); }
[data-cat="11"] { --cat: var(--cat-11); }
[data-cat="12"] { --cat: var(--cat-12); }

/* ---------- 10. 标签与按钮 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid rgba(255, 255, 255, .14);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .1em;
  color: var(--paper-2);
}
.tag--gold {
  border-color: var(--gold-line);
  background: var(--gold-wash);
  color: var(--gold-soft);
}
.tag--cyan {
  border-color: var(--cyan-dim);
  background: rgba(63, 224, 206, .08);
  color: var(--cyan);
}
.tag--coral {
  border-color: var(--coral-dim);
  background: rgba(255, 107, 74, .08);
  color: var(--coral);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 3px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .04em;
  transition: transform .2s ease, box-shadow .25s ease, background-color .25s ease, color .25s ease, border-color .25s ease;
}
.btn--gold {
  background: linear-gradient(150deg, #E0C05A, #B08C1E);
  color: var(--ink);
  box-shadow: 0 16px 32px -22px rgba(201, 162, 39, .95);
}
.btn--gold:hover { transform: translateY(-2px); box-shadow: 0 20px 36px -20px rgba(201, 162, 39, 1); }
.btn--cyan {
  border-color: var(--cyan-dim);
  background: rgba(63, 224, 206, .08);
  color: var(--cyan);
}
.btn--cyan:hover { transform: translateY(-2px); background: rgba(63, 224, 206, .16); }
.btn--ghost {
  border-color: rgba(255, 255, 255, .18);
  color: var(--paper-2);
}
.btn--ghost:hover { border-color: var(--gold-line); color: var(--gold-soft); }
.btn--sm { padding: 8px 14px; font-size: 13px; }

/* ---------- 11. 面包屑 ---------- */
.breadcrumbs { padding: 22px 0 0; }
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}
.breadcrumbs__link {
  color: var(--paper-2);
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}
.breadcrumbs__link:hover,
.breadcrumbs__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan-dim);
}
.breadcrumbs__sep { color: var(--rock); }
.breadcrumbs__item[aria-current="page"] { color: var(--gold-soft); }

/* ---------- 12. 长文排版 ---------- */
.prose { max-width: 38em; }
.prose > * + * { margin-top: 1.05em; }
.prose p { font-size: 17px; color: var(--paper-2); }
.prose h2 {
  margin-top: 1.7em;
  font-size: clamp(22px, 2.6vw, 30px);
}
.prose h3 {
  margin-top: 1.4em;
  font-size: 19px;
  font-weight: 700;
}
.prose ul { list-style: none; }
.prose li {
  position: relative;
  padding-left: 20px;
  color: var(--paper-2);
}
.prose li + li { margin-top: .5em; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 8px;
  height: 1px;
  background: var(--gold);
}
.prose strong { color: var(--paper); font-weight: 700; }
.prose a {
  color: var(--cyan);
  border-bottom: 1px solid var(--cyan-dim);
}
.prose hr {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--gold-line), transparent);
}

/* ---------- 13. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 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)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* ---------- 14. 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid rgba(255, 255, 255, .08);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 90% at 20% 0%, rgba(63, 224, 206, .12), transparent 60%),
    linear-gradient(150deg, var(--ink-2), var(--ink-deep));
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.92) contrast(1.06);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(11, 26, 43, 0) 42%, rgba(11, 26, 43, .74));
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame__caption {
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 14px;
  z-index: 2;
  margin: 0;
  max-width: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--paper-2);
}

/* ---------- 15. 筛选条 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 14px 0 20px;
}
.filter-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 13px;
  border: 1px solid rgba(255, 255, 255, .14);
  border-radius: 2px;
  background: rgba(19, 39, 61, .5);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--paper-2);
  transition: color .2s ease, border-color .2s ease, background-color .2s ease, transform .2s ease;
}
.filter-btn:hover {
  border-color: var(--cyan-dim);
  color: var(--cyan);
  transform: translateY(-1px);
}
.filter-btn[aria-pressed="true"] {
  border-color: var(--gold);
  background: linear-gradient(150deg, #E0C05A, #B08C1E);
  color: var(--ink);
  font-weight: 700;
}
.filter-btn[aria-pressed="true"] .chip-cat { box-shadow: 0 0 0 1px rgba(11, 26, 43, .55); }

.filter-empty {
  display: none;
  padding: 28px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--muted);
}
.filter-empty[data-visible] { display: block; }

[data-filter-item][hidden] { display: none !important; }

/* ---------- 16. 显现动画 ---------- */
[data-reveal] {
  transition: opacity .55s ease, transform .55s cubic-bezier(.22, .7, .3, 1);
}
[data-reveal].reveal-armed {
  opacity: 0;
  transform: translateY(18px);
}
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 17. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 70;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--gold-line);
  border-radius: 3px;
  background: rgba(19, 39, 61, .92);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity .28s ease, transform .28s ease, border-color .28s ease, color .28s ease;
}
.to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: none;
}
.to-top:hover {
  border-color: var(--cyan-dim);
  color: var(--cyan);
}

/* ---------- 18. 响应式 ---------- */
@media (max-width: 1080px) {
  .footer-grid { grid-template-columns: 1.3fr 1fr 1fr; }
  .footer-col:last-of-type { grid-column: 2 / span 2; }
}

@media (max-width: 900px) {
  .site-footer { padding-top: 48px; }

  .header-top { padding: 12px 0 10px; }
  .utility-list { display: none; }
  .brand__meta { display: none; }
  .brand__mark { width: 34px; height: 34px; font-size: 17px; }

  .nav-row {
    height: 0;
    padding: 0;
    overflow: visible;
  }

  .nav-toggle {
    position: absolute;
    top: 14px;
    right: var(--gutter);
    z-index: 90;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border: 1px solid var(--gold-line);
    border-radius: 3px;
    background: rgba(19, 39, 61, .82);
    color: var(--gold-soft);
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: .12em;
  }
  .nav-toggle__bars {
    display: flex;
    flex-direction: column;
    gap: 3px;
  }
  .nav-toggle__bars i {
    display: block;
    width: 16px;
    height: 1.5px;
    background: currentColor;
    transition: transform .25s ease, opacity .25s ease;
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) {
    transform: translateY(4.5px) rotate(45deg);
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) {
    transform: translateY(-4.5px) rotate(-45deg);
  }
  .nav-toggle__label { line-height: 1; }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 85;
    width: min(360px, 88vw);
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 84px 24px 32px;
    overflow-y: auto;
    background: linear-gradient(180deg, #102339, #0B1A2B 72%);
    border-left: 1px solid var(--gold-line);
    box-shadow: -32px 0 64px -44px #000;
    transform: translateX(102%);
    transition: transform .34s cubic-bezier(.22, .7, .3, 1);
  }
  .site-nav[data-open="true"] { transform: translateX(0); }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }
  .site-nav__link {
    justify-content: flex-start;
    padding: 14px 10px;
    border-bottom: 1px solid rgba(255, 255, 255, .07);
    border-radius: 0;
    font-size: 17px;
  }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] {
    color: var(--cyan);
    background: rgba(63, 224, 206, .06);
  }
  .site-nav__foot {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin: 24px 0 0;
  }
  .site-nav__foot .badge {
    justify-content: center;
    padding: 10px 14px;
  }

  body.nav-open { overflow: hidden; }
  body.nav-open::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 70;
    background: rgba(5, 12, 21, .66);
  }

  .layout-split { grid-template-columns: 1fr; }
  .rail {
    position: static;
    top: auto;
  }
  .section__lead { margin-left: 0; }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-col:last-of-type { grid-column: auto; }
  .footer-contact { grid-template-columns: 1fr 1fr; }
  .footer-bottom { justify-content: flex-start; }
}

@media (max-width: 640px) {
  body { font-size: 15.5px; }

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

  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-contact { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .footer-legal-list { gap: 14px; }
  .card { padding: 20px 18px 20px 22px; }
  .to-top { width: 40px; height: 40px; }
}

/* ---------- 19. 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;
  }
  [data-reveal],
  [data-reveal].reveal-armed {
    opacity: 1 !important;
    transform: none !important;
  }
  .site-nav { transition: none; }
  .to-top { transition: none; }
}