/* ==========================================================================
   乐竞赛事 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 头部 / 页脚 / 按钮 / 网格 / 基础组件
   ========================================================================== */

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

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

body {
  margin: 0;
  background: var(--abyss);
  color: var(--score-white);
  font-family: var(--font-body);
  font-size: 18px;
  font-weight: 400;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.08;
  text-transform: uppercase;
}

h1 { font-size: clamp(34px, 5.2vw, 52px); }
h2 { font-size: clamp(26px, 3.6vw, 40px); }
h3 { font-size: clamp(20px, 2.4vw, 26px); }
h4 { font-size: 18px; letter-spacing: 0.08em; }

p { 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; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }

[id] { scroll-margin-top: calc(var(--header-h) + 28px); }

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

/* 2. 变量 ---------------------------------------------------------------- */
:root {
  /* 色彩 */
  --abyss: #040911;
  --sea-slab: #0A1826;
  --grid-slate: #10293B;
  --neon-cyan: #35F0D0;
  --cyan-deep: #13A08C;
  --signal-orange: #FF6A1F;
  --score-white: #F5F9FB;
  --steel-mist: #8EA6B4;
  --line-dim: #1E3A4C;
  --warn-amber: #FFC24B;

  /* 字体 */
  --font-display: "Oswald", "Archivo Narrow", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", "Noto Sans Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 版面 */
  --maxw: 1360px;
  --gutter: clamp(18px, 4vw, 56px);
  --header-h: 76px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --shadow-hard: 8px 8px 0 0 rgba(53, 240, 208, 0.14);
  --scroll-progress: 0;
}

/* 3. 排版工具类 ---------------------------------------------------------- */
.text-mist { color: var(--steel-mist); }
.text-neon { color: var(--neon-cyan); }
.text-orange { color: var(--signal-orange); }

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.08em;
  font-weight: 500;
}
.num--xl { font-size: clamp(56px, 11vw, 132px); line-height: 0.9; }
.num--lg { font-size: clamp(34px, 6vw, 52px); line-height: 0.95; }
.num--md { font-size: 24px; line-height: 1.1; }

.hr-line { height: 1px; background: var(--line-dim); border: 0; margin: 0; }

.pulse {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--neon-cyan);
  animation: pulse-ring 2.4s var(--ease) infinite;
}

@keyframes pulse-ring {
  0%   { box-shadow: 0 0 0 0 rgba(53, 240, 208, 0.5); }
  70%  { box-shadow: 0 0 0 12px rgba(53, 240, 208, 0); }
  100% { box-shadow: 0 0 0 0 rgba(53, 240, 208, 0); }
}

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

.section {
  position: relative;
  padding-block: clamp(56px, 8vw, 120px);
}
.section--slab { background: var(--sea-slab); }
.section--tight { padding-block: clamp(32px, 5vw, 64px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 32px;
  margin-bottom: clamp(24px, 4vw, 48px);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--neon-cyan);
}
.eyebrow::before {
  content: "";
  display: block;
  width: 34px;
  height: 2px;
  background: var(--neon-cyan);
  flex: none;
}

.section-title { font-size: clamp(28px, 4vw, 52px); }
.section-sub { max-width: 68ch; color: var(--steel-mist); font-size: 16px; }
.lede {
  max-width: 68ch;
  font-size: clamp(18px, 2vw, 24px);
  line-height: 1.7;
  color: var(--score-white);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}
.span-1 { grid-column: span 1; }
.span-2 { grid-column: span 2; }
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-10 { grid-column: span 10; }
.span-11 { grid-column: span 11; }
.span-12 { grid-column: span 12; }
.start-1 { grid-column-start: 1; }
.start-2 { grid-column-start: 2; }
.start-3 { grid-column-start: 3; }
.start-4 { grid-column-start: 4; }
.start-5 { grid-column-start: 5; }
.start-6 { grid-column-start: 6; }
.start-7 { grid-column-start: 7; }
.start-8 { grid-column-start: 8; }

/* 5. 按钮 ---------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 24px;
  border: 2px solid var(--line-dim);
  background: var(--grid-slate);
  color: var(--score-white);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease),
              border-color 0.18s var(--ease), transform 0.18s var(--ease),
              box-shadow 0.18s var(--ease);
}
.btn:hover { border-color: var(--cyan-deep); }
.btn:active { transform: translate(2px, 2px); box-shadow: none; }

.btn--primary {
  background: var(--neon-cyan);
  border-color: var(--neon-cyan);
  color: var(--abyss);
  box-shadow: 6px 6px 0 0 rgba(19, 160, 140, 0.35);
}
.btn--primary:hover {
  background: var(--cyan-deep);
  border-color: var(--cyan-deep);
  color: var(--score-white);
  transform: translate(-2px, -2px);
  box-shadow: 9px 9px 0 0 rgba(19, 160, 140, 0.4);
}
.btn--ghost { background: transparent; }
.btn--sm { padding: 10px 16px; font-size: 13px; }

/* 6. 面包屑与正文 -------------------------------------------------------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--steel-mist);
}
.breadcrumbs a { color: var(--steel-mist); transition: color 0.16s var(--ease); }
.breadcrumbs a:hover { color: var(--neon-cyan); }
.breadcrumbs li { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumbs li::after { content: "/"; color: var(--line-dim); }
.breadcrumbs li:last-child::after { content: ""; }

.prose { max-width: 68ch; font-size: 18px; line-height: 1.75; }
.prose > * + * { margin-top: 1.2em; }
.prose p { margin: 0; }
.prose h2 { margin-top: 1.8em; font-size: clamp(24px, 3vw, 34px); }
.prose h3 { margin-top: 1.6em; }
.prose a { color: var(--neon-cyan); border-bottom: 1px solid var(--line-dim); }
.prose a:hover { border-bottom-color: var(--neon-cyan); }
.prose ul, .prose ol { display: flex; flex-direction: column; gap: 0.6em; }
.prose li { padding-left: 1.4em; position: relative; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.8em;
  width: 10px; height: 1px;
  background: var(--neon-cyan);
}

/* 7. 数据组件 ------------------------------------------------------------ */
.panel {
  padding: clamp(18px, 3vw, 28px);
  background: var(--grid-slate);
  border: 2px solid var(--line-dim);
  box-shadow: var(--shadow-hard);
}
.panel--flat { background: var(--sea-slab); box-shadow: none; border-width: 1px; }

.metric-row {
  display: grid;
  gap: clamp(16px, 3vw, 32px);
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}
.metric { display: flex; flex-direction: column; gap: 6px; }
.metric-value {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 52px);
  letter-spacing: 0.06em;
  line-height: 1;
  color: var(--score-white);
}
.metric-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--steel-mist);
}
.metric--accent .metric-value { color: var(--neon-cyan); }
.metric--alert .metric-value { color: var(--signal-orange); }

.ledger { border-top: 1px solid var(--line-dim); }
.ledger-row {
  display: grid;
  grid-template-columns: minmax(72px, auto) 1fr auto;
  gap: 12px clamp(12px, 3vw, 32px);
  align-items: baseline;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-dim);
}
.ledger-key {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--neon-cyan);
}
.ledger-title { font-family: var(--font-display); font-size: clamp(18px, 2.2vw, 24px); line-height: 1.3; }
.ledger-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel-mist);
}

/* 8. 标签与提示 ---------------------------------------------------------- */
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line-dim);
  background: var(--sea-slab);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--steel-mist);
  transition: background-color 0.16s var(--ease), border-color 0.16s var(--ease), color 0.16s var(--ease);
}
.tag:hover { border-color: var(--cyan-deep); color: var(--score-white); }
.tag[aria-pressed="true"],
.tag.is-active {
  background: var(--cyan-deep);
  border-color: var(--neon-cyan);
  color: var(--score-white);
}
.tag--alert { border-color: var(--signal-orange); color: var(--signal-orange); }

.callout {
  padding: 16px 20px;
  border-left: 3px solid var(--warn-amber);
  background: var(--sea-slab);
  font-size: 15px;
  line-height: 1.7;
  color: var(--score-white);
}
.callout--alert { border-left-color: var(--signal-orange); }
.callout--neon { border-left-color: var(--neon-cyan); }

/* 9. 图片容器基础规则（页面阶段放置图片占位） ---------------------------- */
.frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--sea-slab);
  border: 1px solid var(--line-dim);
}
.frame > img,
.frame > svg,
.frame > .frame-placeholder {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.frame--21x9 { aspect-ratio: 21 / 9; }
.frame--16x9 { aspect-ratio: 16 / 9; }
.frame--4x3 { aspect-ratio: 4 / 3; }
.frame--1x1 { aspect-ratio: 1 / 1; }
.frame--3x4 { aspect-ratio: 3 / 4; }
.frame--slant { clip-path: polygon(0 0, 100% 4%, 100% 100%, 0 96%); }
.frame--tilt { transform: rotate(-1.4deg); }

.frame-placeholder {
  display: grid;
  place-items: center;
  text-align: center;
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--steel-mist);
  background: repeating-linear-gradient(
    135deg,
    var(--grid-slate) 0 12px,
    var(--sea-slab) 12px 24px
  );
}

.frame-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--steel-mist);
}

.frame-grid {
  display: grid;
  gap: clamp(12px, 2vw, 24px);
  grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
}

/* 10. 章节轨 / 进度 / 返回顶部 ------------------------------------------- */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  z-index: 90;
  width: 100%;
  height: 2px;
  transform: scaleX(var(--scroll-progress));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan-deep), var(--neon-cyan));
  pointer-events: none;
}

.rail {
  display: flex;
  flex-direction: column;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}
.rail-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 2px 0;
  color: var(--steel-mist);
  transition: color 0.16s var(--ease);
}
.rail-link::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--line-dim);
  flex: none;
  transition: width 0.16s var(--ease), background-color 0.16s var(--ease);
}
.rail-link:hover { color: var(--score-white); }
.rail-link[aria-current="true"] { color: var(--neon-cyan); }
.rail-link[aria-current="true"]::before { width: 30px; background: var(--neon-cyan); }

.top-btn {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border: 2px solid var(--line-dim);
  background: var(--grid-slate);
  color: var(--score-white);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease),
              visibility 0.24s var(--ease), border-color 0.16s var(--ease), color 0.16s var(--ease);
}
.top-btn[data-visible="true"] { opacity: 1; visibility: visible; transform: none; }
.top-btn:hover { border-color: var(--neon-cyan); color: var(--neon-cyan); }

/* 11. 入场显现 ----------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
[data-reveal].is-in { opacity: 1; transform: none; }

/* 12. 跳过链接 ----------------------------------------------------------- */
.skip-link {
  position: absolute;
  top: 8px;
  left: var(--gutter);
  z-index: 120;
  padding: 10px 16px;
  background: var(--neon-cyan);
  color: var(--abyss);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  transform: translateY(-200%);
  transition: transform 0.2s var(--ease);
}
.skip-link:focus { transform: none; }

/* 13. 头部 --------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.24s var(--ease), border-color 0.24s var(--ease),
              backdrop-filter 0.24s var(--ease);
}
.site-header[data-scrolled="true"] {
  background: rgba(4, 9, 17, 0.94);
  border-bottom-color: var(--line-dim);
  backdrop-filter: blur(12px) saturate(130%);
}

.announce-bar {
  max-height: 44px;
  overflow: hidden;
  background: var(--sea-slab);
  border-bottom: 1px solid var(--line-dim);
  transition: max-height 0.24s var(--ease), opacity 0.24s var(--ease);
}
.site-header[data-scrolled="true"] .announce-bar { max-height: 0; opacity: 0; }

.announce-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 40px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
}
.announce-text {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--score-white);
}
.announce-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--neon-cyan);
  flex: none;
  animation: pulse-ring 2.4s var(--ease) infinite;
}
.announce-link {
  flex: none;
  color: var(--neon-cyan);
  text-transform: uppercase;
  white-space: nowrap;
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}
.announce-link:hover { color: var(--score-white); border-bottom-color: var(--neon-cyan); }

.header-bar { position: relative; z-index: 3; }

.header-inner {
  display: flex;
  align-items: center;
  gap: clamp(16px, 3vw, 40px);
  min-height: var(--header-h);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: none;
  margin-right: auto;
}
.brand-mark {
  position: relative;
  display: block;
  width: 34px;
  height: 34px;
  flex: none;
  background: var(--abyss);
  border: 2px solid var(--neon-cyan);
}
.brand-mark::before {
  content: "";
  position: absolute;
  left: 5px; right: 5px; bottom: 6px;
  height: 2px;
  background: var(--neon-cyan);
}
.brand-mark::after {
  content: "";
  position: absolute;
  top: 6px; left: 6px;
  width: 7px; height: 7px;
  background: var(--signal-orange);
}
.brand-text { display: flex; flex-direction: column; gap: 3px; }
.brand-name {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.brand-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.2em;
  color: var(--steel-mist);
  text-transform: uppercase;
}

.site-nav { display: flex; align-items: center; z-index: 1; }
.nav-list { display: flex; align-items: center; gap: clamp(10px, 1.6vw, 26px); }
.nav-link {
  position: relative;
  display: inline-block;
  padding: 10px 2px;
  font-size: 15px;
  line-height: 1.2;
  color: var(--score-white);
  opacity: 0.72;
  transition: opacity 0.16s var(--ease), color 0.16s var(--ease);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 2px;
  height: 2px;
  background: var(--neon-cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.16s var(--ease);
}
.nav-link:hover { opacity: 1; }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { opacity: 1; color: var(--neon-cyan); }
.nav-link[aria-current="page"]::after { transform: scaleX(1); }

.nav-cta { display: none; }
.header-actions { display: flex; align-items: center; gap: 12px; flex: none; }
.header-cta { display: inline-flex; }

.nav-toggle {
  display: none;
  position: relative;
  width: 46px;
  height: 46px;
  flex: none;
  border: 2px solid var(--line-dim);
  background: var(--grid-slate);
  transition: border-color 0.16s var(--ease);
}
.nav-toggle:hover { border-color: var(--neon-cyan); }
.nav-toggle-bar {
  position: absolute;
  left: 12px; right: 12px;
  height: 2px;
  background: var(--score-white);
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}
.nav-toggle-bar:nth-child(1) { top: 15px; }
.nav-toggle-bar:nth-child(2) { top: 22px; }
.nav-toggle-bar:nth-child(3) { top: 29px; }
.nav-toggle[aria-expanded="true"] { border-color: var(--neon-cyan); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

html[data-nav-open="true"] { overflow: hidden; }
html[data-nav-open="true"] .site-header {
  background: rgba(4, 9, 17, 0.98);
  border-bottom-color: var(--line-dim);
}
html[data-nav-open="true"] .announce-bar { max-height: 0; opacity: 0; }

/* 14. 页脚 --------------------------------------------------------------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 110px);
  background: var(--abyss);
  border-top: 1px solid var(--line-dim);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px; left: 0;
  width: 140px;
  height: 2px;
  background: var(--neon-cyan);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(220px, 1.1fr) minmax(0, 2fr) minmax(200px, 1fr);
  gap: clamp(28px, 4vw, 64px);
  padding-block: clamp(40px, 6vw, 76px);
}

.footer-brand { display: flex; flex-direction: column; gap: 12px; max-width: 34ch; }
.footer-brand .brand-mark { align-self: flex-start; }
.footer-brand-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1;
  text-transform: uppercase;
}
.footer-brand-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--neon-cyan);
  text-transform: uppercase;
}
.footer-note { font-size: 14px; line-height: 1.7; color: var(--steel-mist); }

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 3vw, 32px);
}
.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--neon-cyan);
}
.footer-list { display: flex; flex-direction: column; gap: 10px; }
.footer-list a {
  font-size: 15px;
  color: var(--score-white);
  opacity: 0.78;
  transition: opacity 0.16s var(--ease), color 0.16s var(--ease);
}
.footer-list a:hover { opacity: 1; color: var(--neon-cyan); }
.footer-list--mono {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--steel-mist);
}
.footer-list--mono li { line-height: 1.6; }
.footer-key {
  display: block;
  margin-bottom: 2px;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--steel-mist);
  opacity: 0.8;
}
.footer-contact { display: flex; flex-direction: column; gap: 14px; }

.footer-legal {
  background: var(--sea-slab);
  border-top: 1px solid var(--line-dim);
}
.footer-legal-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 32px;
  padding-block: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel-mist);
}

/* 15. 响应式 ------------------------------------------------------------- */
@media (max-width: 1020px) {
  .nav-toggle { display: block; }

  .site-nav {
    position: fixed;
    inset: 0;
    z-index: 1;
    display: flex;
    flex-direction: column;
    gap: 0;
    padding: calc(var(--header-h) + 28px) var(--gutter) 48px;
    background: var(--sea-slab);
    border-right: 1px solid var(--line-dim);
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform 0.28s var(--ease);
  }
  .site-nav[data-open="true"] { transform: translateX(0); }
  .site-nav[data-open="false"] { visibility: hidden; }

  .nav-list { flex-direction: column; align-items: stretch; gap: 0; }
  .nav-link {
    padding: 16px 0;
    font-family: var(--font-display);
    font-size: 24px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    opacity: 1;
    border-bottom: 1px solid var(--line-dim);
  }
  .nav-link::after { bottom: 0; }
  .nav-cta { display: inline-flex; align-self: flex-start; margin-top: 28px; }
}

@media (max-width: 960px) {
  .grid { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .span-1, .span-2, .span-3,
  .span-4, .span-5, .span-6 { grid-column: span 6; }
  .span-7, .span-8, .span-9,
  .span-10, .span-11, .span-12 { grid-column: span 6; }
  .start-1, .start-2, .start-3, .start-4,
  .start-5, .start-6, .start-7, .start-8 { grid-column-start: auto; }

  .footer-inner { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 620px) {
  body { font-size: 17px; }
  .grid { grid-template-columns: minmax(0, 1fr); }
  [class*="span-"] { grid-column: span 1; }
  .footer-nav { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .footer-legal-inner { flex-direction: column; }
  .announce-link { display: none; }
  .ledger-row { grid-template-columns: minmax(0, 1fr); gap: 6px; }
}

@media (max-width: 520px) {
  .header-cta { display: none; }
}

/* 16. 动效与可访问性降级 -------------------------------------------------- */
@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;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .announce-dot { animation: none; }
  .frame--tilt { transform: none; }
}