/* ============================================================
   LUCKY赛场 · /assets/site.css
   共享外壳：设计变量、中文排版、刊头、版权页、基础组件
   ============================================================ */

/* ---------- 01. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

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

ul, ol { padding: 0; list-style: none; }

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

button { font: inherit; color: inherit; background: none; border: 0; }

:focus-visible {
  outline: 2px solid var(--gold-300);
  outline-offset: 3px;
  border-radius: 2px;
}

::selection { background: var(--gold-500); color: var(--ink-900); }

/* ---------- 02. Tokens ---------- */
:root {
  color-scheme: dark;

  /* 色板 */
  --ink-900: #0A1A2F;
  --ink-800: #0F2440;
  --ink-700: #16325A;
  --glass: rgba(255, 255, 255, 0.08);
  --glass-strong: rgba(255, 255, 255, 0.14);
  --gold-500: #FFD700;
  --gold-300: #FFE873;
  --amber-700: #B8860B;
  --orange-500: #FF6B35;
  --green-500: #2ECC71;
  --paper-50: #F7F8FB;
  --slate-600: #4A5A72;
  --line: rgba(255, 255, 255, 0.14);
  --line-strong: rgba(255, 255, 255, 0.24);
  --text-dim: rgba(247, 248, 251, 0.66);

  /* 字体 */
  --font-display: "Montserrat", "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Roboto", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "PingFang SC", "Microsoft YaHei", monospace;

  /* 网格与节奏 */
  --shell: 1320px;
  --gutter: clamp(16px, 3.2vw, 40px);
  --gap-96: 96px;
  --gap-56: 56px;
  --gap-24: 24px;
  --header-h: 84px;

  /* 动效 */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur-1: 180ms;
  --dur-2: 280ms;
  --dur-3: 420ms;
}

/* ---------- 03. 中文排版基线 ---------- */
body {
  margin: 0;
  background: var(--ink-900);
  color: var(--paper-50);
  font-family: var(--font-body);
  font-size: clamp(16px, 1.05vw, 18px);
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body,
input,
button,
select,
textarea { font-synthesis-weight: none; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper-50);
}

h1 { font-size: clamp(40px, 7vw, 96px); line-height: 1.04; }
h2 { font-size: clamp(28px, 3.6vw, 44px); }
h3 { font-size: clamp(20px, 2vw, 28px); line-height: 1.3; }
h4 { font-size: clamp(17px, 1.4vw, 20px); }

a { text-underline-offset: 3px; }

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

/* ---------- 04. 工具类 ---------- */
.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;
}

.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.page-shell { padding-block: clamp(32px, 5vw, 72px); }

.paper-zone {
  background: var(--paper-50);
  color: var(--ink-900);
  padding-block: clamp(40px, 6vw, 88px);
}

.paper-zone h2,
.paper-zone h3,
.paper-zone h4 { color: var(--ink-900); }

.paper-zone .stat__value { color: var(--amber-700); }
.paper-zone .stat__label { color: var(--slate-600); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--gold-500);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}

.vert-note {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.32em;
  white-space: nowrap;
  color: rgba(255, 215, 0, 0.72);
  margin: 0;
}

.num,
.stat__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

/* ---------- 05. 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -100px;
  z-index: 200;
  display: inline-block;
  padding: 10px 18px;
  background: var(--gold-500);
  color: var(--ink-900);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  text-decoration: none;
  border-radius: 2px;
  transition: top var(--dur-2) var(--ease);
}

.skip-link:focus { top: 12px; }

/* ---------- 06. 刊头 / Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: rgba(10, 26, 47, 0.9);
  color: var(--paper-50);
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
  transition: background var(--dur-2) var(--ease), box-shadow var(--dur-2) var(--ease);
}

.site-header[data-scrolled] {
  background: rgba(10, 26, 47, 0.985);
  box-shadow: 0 18px 44px -28px rgba(0, 0, 0, 0.95);
}

.site-header__shell {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 30px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: var(--header-h);
  transition: min-height var(--dur-2) var(--ease);
}

.site-header[data-scrolled] .site-header__shell { min-height: 56px; }

.site-header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--gold-500), var(--orange-500));
  pointer-events: none;
}

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

.brand__mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 1px solid var(--gold-500);
  transform: rotate(45deg);
  transition: transform var(--dur-3) var(--ease), border-color var(--dur-2) var(--ease);
}

.brand__mark::before {
  content: "";
  width: 10px;
  height: 10px;
  background: var(--gold-500);
  transition: background var(--dur-2) var(--ease);
}

.brand:hover .brand__mark,
.brand:focus-visible .brand__mark {
  transform: rotate(135deg);
  border-color: var(--gold-300);
}

.brand:hover .brand__mark::before { background: var(--gold-300); }

.brand__text { display: grid; gap: 3px; line-height: 1; }

.brand__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: 0.02em;
  color: var(--paper-50);
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--text-dim);
  text-transform: lowercase;
  transition: opacity var(--dur-2) var(--ease);
}

.site-header[data-scrolled] .brand__sub { opacity: 0; }

/* 导航：左组贴品牌，右组贴画面右端，中段玻璃胶囊 */
.site-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.4vw, 24px);
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.5vw, 26px);
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 8px 2px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  white-space: nowrap;
  text-decoration: none;
  color: rgba(247, 248, 251, 0.78);
  transition: color var(--dur-1) var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 2px;
  height: 2px;
  background: var(--gold-500);
  transition: right var(--dur-2) var(--ease);
}

.site-nav__link:hover,
.site-nav__link:focus-visible { color: var(--paper-50); }
.site-nav__link:hover::after { right: 0; }

.site-nav__link[aria-current="page"] { color: var(--gold-500); }
.site-nav__link[aria-current="page"]::after { right: 0; }

.site-nav__spine {
  margin-inline: auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--glass);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  white-space: nowrap;
  color: var(--text-dim);
}

.site-nav__spine::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--green-500);
  box-shadow: 0 0 0 3px rgba(46, 204, 113, 0.18);
}

.header-cta { flex: 0 0 auto; }

/* 抽屉开关 */
.nav-toggle {
  display: none;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: var(--glass);
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  cursor: pointer;
  transition: border-color var(--dur-1) var(--ease), background var(--dur-1) var(--ease);
}

.nav-toggle:hover { border-color: var(--gold-500); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--paper-50);
  transition: background var(--dur-1) var(--ease);
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--paper-50);
  transition: transform var(--dur-2) var(--ease), background var(--dur-1) var(--ease);
}

.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }

.site-header[data-open] .nav-toggle__bars { background: transparent; }
.site-header[data-open] .nav-toggle__bars::before {
  transform: translateY(6px) rotate(45deg);
  background: var(--gold-500);
}
.site-header[data-open] .nav-toggle__bars::after {
  transform: translateY(-6px) rotate(-45deg);
  background: var(--gold-500);
}

/* ---------- 07. 按钮 ---------- */
.btn {
  --btn-bg: var(--gold-500);
  --btn-fg: var(--ink-900);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 2px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--dur-2) var(--ease),
              background var(--dur-2) var(--ease),
              color var(--dur-2) var(--ease),
              border-color var(--dur-2) var(--ease);
}

.btn:hover { transform: translateY(-2px); }

.btn--gold { --btn-bg: var(--gold-500); --btn-fg: var(--ink-900); }
.btn--gold:hover { --btn-bg: var(--gold-300); }

.btn--ghost {
  --btn-bg: var(--glass);
  --btn-fg: var(--paper-50);
  border-color: var(--line-strong);
}
.btn--ghost:hover {
  --btn-bg: var(--glass-strong);
  border-color: var(--gold-500);
}

.btn--orange { --btn-bg: var(--orange-500); --btn-fg: #FFFFFF; }
.btn--orange:hover { --btn-bg: #FF8355; }

.btn--sm { padding: 9px 16px; font-size: 12.5px; letter-spacing: 0.06em; }

/* ---------- 08. 版权页 / Footer ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  background: var(--ink-900);
  border-top: 1px solid var(--line);
  color: var(--text-dim);
  padding-block: clamp(48px, 7vw, 96px) 28px;
}

.site-footer__glow {
  position: absolute;
  top: -180px;
  right: -140px;
  width: 560px;
  height: 560px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 215, 0, 0.14), rgba(255, 215, 0, 0) 68%);
  pointer-events: none;
}

.site-footer__shell {
  position: relative;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-footer__masthead {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px 32px;
}

.site-footer__brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 5vw, 56px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper-50);
}

.site-footer__brand span { color: var(--gold-500); }

.site-footer__line {
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--text-dim);
  max-width: 34ch;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 0.8fr 0.8fr 0.8fr 1.5fr;
  gap: clamp(28px, 3.4vw, 56px);
  margin-top: clamp(32px, 4.5vw, 56px);
  padding-top: clamp(28px, 3.5vw, 44px);
  border-top: 1px solid var(--line);
}

.site-footer__about {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.site-footer__note {
  font-size: 13px;
  line-height: 1.9;
  color: var(--text-dim);
  max-width: 26ch;
}

.site-footer__group-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: rgba(247, 248, 251, 0.42);
  margin: 0 0 16px;
}

.site-footer__links { display: grid; gap: 10px; }

.site-footer__link {
  position: relative;
  display: inline-block;
  width: fit-content;
  font-size: 14px;
  text-decoration: none;
  color: rgba(247, 248, 251, 0.82);
  transition: color var(--dur-1) var(--ease), transform var(--dur-1) var(--ease);
}

.site-footer__link:hover,
.site-footer__link:focus-visible {
  color: var(--gold-500);
  transform: translateX(3px);
}

.site-footer__contact {
  display: grid;
  gap: 12px;
  align-content: start;
}

.site-footer__contact-row { display: grid; gap: 2px; }

.site-footer__contact-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.24em;
  color: rgba(247, 248, 251, 0.4);
}

.site-footer__contact-value {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.01em;
  color: var(--paper-50);
  overflow-wrap: anywhere;
}

.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 28px;
  margin-top: clamp(32px, 4vw, 56px);
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(247, 248, 251, 0.5);
}

.site-footer__copy,
.site-footer__icp { margin: 0; }

/* ---------- 09. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--text-dim);
}

.breadcrumb__item { margin: 0; }

.breadcrumb__item[aria-current="page"] { color: var(--gold-500); }

.breadcrumb a {
  text-decoration: none;
  color: inherit;
  transition: color var(--dur-1) var(--ease);
}

.breadcrumb a:hover { color: var(--gold-300); }

.breadcrumb__sep { color: rgba(247, 248, 251, 0.3); }

/* ---------- 10. 正文容器 ---------- */
.prose {
  max-width: 66ch;
  color: rgba(247, 248, 251, 0.86);
}

.prose > * + * { margin-top: 1.1em; }

.prose h2,
.prose h3 { margin-top: 1.9em; }

.prose a { color: var(--gold-500); }

.prose ul { display: grid; gap: 0.6em; }

.prose ul li {
  position: relative;
  padding-left: 1.4em;
}

.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.74em;
  width: 8px;
  height: 2px;
  background: var(--gold-500);
}

.paper-zone .prose { color: var(--slate-600); }
.paper-zone .prose h2,
.paper-zone .prose h3 { color: var(--ink-900); }
.paper-zone .prose a { color: var(--amber-700); }

/* ---------- 11. 网格 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 32px);
}

.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

/* ---------- 12. 编号章节头 ---------- */
.section-head {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: clamp(16px, 2vw, 28px);
}

.section-head__index {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 56px);
  font-weight: 500;
  line-height: 0.9;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--gold-500);
}

.section-head__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3vw, 36px);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--paper-50);
  margin: 0;
}

.section-head__note {
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
  margin: 8px 0 0;
  max-width: 52ch;
}

.paper-zone .section-head__title { color: var(--ink-900); }
.paper-zone .section-head__note { color: var(--slate-600); }

/* ---------- 13. 图片容器 ---------- */
.media-frame {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: 2px;
}

.media-frame > img,
.media-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame::after {
  content: "";
  position: absolute;
  right: 12px;
  bottom: 12px;
  width: 16px;
  height: 16px;
  border-right: 2px solid var(--gold-500);
  border-bottom: 2px solid var(--gold-500);
  pointer-events: none;
}

.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--paper { background: var(--paper-50); border-color: rgba(10, 26, 47, 0.12); }

/* ---------- 14. 目录卡片 ---------- */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2vw, 26px);
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: 2px;
  color: inherit;
  text-decoration: none;
  transition: transform var(--dur-2) var(--ease),
              border-color var(--dur-2) var(--ease),
              background var(--dur-2) var(--ease);
}

.card:hover,
.card:focus-visible {
  transform: translateY(-2px);
  border-color: rgba(255, 215, 0, 0.55);
  background: var(--ink-700);
}

.card__index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  font-variant-numeric: tabular-nums;
  color: var(--gold-500);
}

.card__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.3;
  letter-spacing: 0;
  color: var(--paper-50);
  margin: 0;
}

.card__meta {
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-dim);
  margin: 0;
}

/* ---------- 15. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-decoration: none;
  color: var(--text-dim);
}

.tag--gold { color: var(--gold-500); border-color: rgba(255, 215, 0, 0.45); }
.tag--orange { color: var(--orange-500); border-color: rgba(255, 107, 53, 0.5); }
.tag--green { color: var(--green-500); border-color: rgba(46, 204, 113, 0.5); }

/* ---------- 16. 统计数字 ---------- */
.stat { display: grid; gap: 4px; }

.stat__value {
  font-size: clamp(28px, 3.4vw, 42px);
  font-weight: 500;
  line-height: 1;
  color: var(--gold-500);
}

.stat__label {
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-dim);
}

/* ---------- 17. 筛选条 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 12px;
  background: var(--glass);
  border: 1px solid var(--line);
  border-radius: 2px;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.filter-btn {
  padding: 8px 16px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  cursor: pointer;
  transition: color var(--dur-1) var(--ease),
              background var(--dur-1) var(--ease),
              border-color var(--dur-1) var(--ease);
}

.filter-btn:hover {
  color: var(--paper-50);
  border-color: var(--line-strong);
}

.filter-btn[aria-pressed="true"] {
  background: var(--gold-500);
  border-color: var(--gold-500);
  color: var(--ink-900);
}

.filter-status {
  flex-basis: 100%;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--text-dim);
}

[data-filter-item][data-filter-state="out"] { display: none !important; }

/* ---------- 18. 显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--dur-3) var(--ease), transform var(--dur-3) var(--ease);
  will-change: opacity, transform;
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
  will-change: auto;
}

/* ---------- 19. 响应式 ---------- */
@media (max-width: 1080px) {
  .site-footer__grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .site-footer__about { grid-column: 1 / -1; align-items: center; }
  .site-footer__contact {
    grid-column: 1 / -1;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  }
}

@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  .site-header__shell { min-height: 64px; gap: 10px; }
  .site-header[data-scrolled] .site-header__shell { min-height: 56px; }
  .brand__sub { display: none; }
  .header-cta { margin-inline-start: auto; }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
    padding: 12px var(--gutter) 28px;
    background: rgba(10, 26, 47, 0.99);
    border-bottom: 1px solid var(--line-strong);
    box-shadow: 0 24px 48px -24px rgba(0, 0, 0, 0.95);
  }

  .site-header[data-open] .site-nav { display: flex; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__list + .site-nav__list {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid var(--line);
  }

  .site-nav__link {
    display: block;
    padding: 14px 4px;
    font-size: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .site-nav__link::after { display: none; }

  .site-nav__link[aria-current="page"] {
    color: var(--gold-500);
    box-shadow: inset 3px 0 0 var(--gold-500);
    padding-left: 14px;
  }

  .site-nav__spine { display: none; }

  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-7, .col-8, .col-6 { grid-column: span 6; }
  .col-4, .col-5 { grid-column: span 3; }
}

@media (max-width: 640px) {
  .site-footer { padding-block: 48px 24px; }
  .site-footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .site-footer__contact { grid-template-columns: 1fr; }
  .site-footer__base { flex-direction: column; align-items: flex-start; }
  .media-frame { aspect-ratio: 4 / 3; }
  .media-frame--tall { aspect-ratio: 3 / 4; }
  .media-frame--wide { aspect-ratio: 16 / 9; }
  .section-head { grid-template-columns: 1fr; gap: 10px; }
  .header-cta { padding: 9px 14px; font-size: 12px; }
  .brand__name { font-size: 16px; }
}

@media (max-width: 400px) {
  .brand__mark { width: 28px; height: 28px; }
  .brand__mark::before { width: 8px; height: 8px; }
  .grid-12 { grid-template-columns: 1fr; }
  .col-4, .col-5, .col-6, .col-7, .col-8, .col-12 { grid-column: span 1; }
}

/* ---------- 20. 降低动态偏好 ---------- */
@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;
    scroll-behavior: auto !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .btn:hover,
  .card:hover,
  .card:focus-visible,
  .site-footer__link:hover { transform: none; }
}