/* ============================================================
   完美电竞主站 · /assets/site.css
   共享层：reset / 变量 / 中文排版 / 头部 / 页脚 / 基础组件
   ============================================================ */

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

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

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

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

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

img { height: auto; }

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

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

table { border-collapse: collapse; }

[hidden] { display: none !important; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 色彩体系 */
  --c-void: #05070F;
  --c-panel: #0B1024;
  --c-rib: #161D38;
  --c-deep: #1B2A6B;
  --c-neon: #6C3BFF;
  --c-pulse: #29E7D6;
  --c-alert: #FF6A2B;
  --c-gold: #FFC94D;
  --c-text: #E9EDFB;
  --c-dim: #9AA6C9;
  --c-mute: #5A6488;
  --c-line: #1E2748;
  --c-line-strong: #3A4780;

  /* 字体 */
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --font-body: Inter, "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Consolas, "Courier New", monospace;

  /* 尺度 */
  --shell: 1280px;
  --gutter: clamp(16px, 3vw, 40px);
  --strip-h: 44px;
  --edge: 2px;
  --shadow-stack: 0 24px 40px rgba(5, 7, 15, 0.6);
  --dur-fast: 180ms;
  --dur: 240ms;
}

/* ---------- 3. 基础排版 ---------- */
html { scroll-behavior: smooth; }

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background-color: var(--c-void);
  background-image:
    linear-gradient(rgba(41, 231, 214, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(41, 231, 214, 0.045) 1px, transparent 1px);
  background-size: 64px 64px, 64px 64px;
  background-position: -1px -1px, -1px -1px;
  letter-spacing: 0.01em;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: 0.01em;
}

h1 { font-size: clamp(40px, 5.6vw, 56px); }
h2 { font-size: clamp(24px, 2.6vw, 30px); }
h3 { font-size: 20px; }

p { overflow-wrap: anywhere; }

a:hover { color: var(--c-pulse); }

:focus-visible {
  outline: 3px solid var(--c-pulse);
  outline-offset: 3px;
}

[id] { scroll-margin-top: calc(var(--strip-h) + 84px); }

/* 等宽数字基元 */
.num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

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

.grid { display: grid; gap: clamp(16px, 2.4vw, 32px); }

.grid--asym { grid-template-columns: minmax(220px, 3fr) minmax(0, 7fr); }
.grid--halves { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--thirds { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

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

.rule {
  height: var(--edge);
  border: 0;
  margin-block: clamp(20px, 3vw, 40px);
  background: linear-gradient(90deg, var(--c-line-strong), rgba(58, 71, 128, 0));
}

.rule--ticked {
  height: 10px;
  background-image: repeating-linear-gradient(90deg, var(--c-line-strong) 0 2px, transparent 2px 14px);
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: -140px;
  left: clamp(12px, 3vw, 40px);
  z-index: 200;
  padding: 12px 22px;
  border: var(--edge) solid #04121A;
  background: var(--c-pulse);
  color: #04121A;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: top var(--dur-fast) ease;
}

.skip-link:focus {
  top: 12px;
  color: #04121A;
}

/* ---------- 6. 头部 ---------- */
.site-header {
  position: sticky;
  top: calc(-1 * var(--strip-h));
  z-index: 80;
  background: var(--c-void);
}

/* 6.1 上层品牌说明条 */
.brand-strip {
  background: linear-gradient(90deg, var(--c-void) 0%, #070B18 42%, var(--c-void) 100%);
  border-bottom: var(--edge) solid var(--c-rib);
  color: var(--c-dim);
  font-size: 12px;
}

.brand-strip__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2.4vw, 32px);
  min-height: 44px;
  padding-block: 6px;
}

.brand-mark {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  flex: 0 0 auto;
}

.brand-mark__glyph {
  flex: none;
  width: 24px;
  height: 24px;
  border: var(--edge) solid var(--c-pulse);
  background: linear-gradient(135deg, var(--c-neon) 0 52%, rgba(5, 7, 15, 0.2) 52%);
  box-shadow: 0 0 0 1px rgba(41, 231, 214, 0.28), inset 0 0 14px rgba(41, 231, 214, 0.35);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}

.brand-mark__text { display: flex; flex-direction: column; line-height: 1.25; min-width: 0; }

.brand-mark__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  color: var(--c-text);
  letter-spacing: 0.04em;
}

.brand-mark__sub {
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-mute);
}

.brand-strip__note {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-mute);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand-strip__meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}

/* 6.2 状态标签 */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid var(--c-line-strong);
  background: var(--c-rib);
  color: var(--c-dim);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

.chip--cyan { border-color: var(--c-pulse); color: var(--c-pulse); background: rgba(41, 231, 214, 0.1); }
.chip--violet { border-color: var(--c-neon); color: #C9B6FF; background: rgba(108, 59, 255, 0.14); }
.chip--alert { border-color: var(--c-alert); color: var(--c-alert); background: rgba(255, 106, 43, 0.12); }
.chip--gold { border-color: var(--c-gold); color: var(--c-gold); background: rgba(255, 201, 77, 0.12); }
.chip--ghost { border-color: var(--c-line); color: var(--c-mute); background: transparent; }

/* 6.3 下层栏目轨道 */
.nav-rail {
  position: relative;
  background: var(--c-panel);
  border-bottom: var(--edge) solid var(--c-line-strong);
  transition: box-shadow var(--dur-fast) ease;
}

.site-header[data-stuck] .nav-rail {
  box-shadow: 0 12px 28px rgba(5, 7, 15, 0.72), inset 0 -1px 0 rgba(41, 231, 214, 0.35);
}

.nav-rail__inner {
  display: flex;
  align-items: stretch;
  gap: clamp(12px, 2vw, 24px);
  min-height: 58px;
}

.primary-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.primary-nav__list {
  display: flex;
  align-items: stretch;
  gap: 2px;
  height: 100%;
  overflow-x: auto;
  scrollbar-width: thin;
}

.primary-nav__item { display: flex; }

.primary-nav__link {
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0 16px;
  border-bottom: 3px solid transparent;
  color: var(--c-dim);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  white-space: nowrap;
  transition: color var(--dur-fast) ease, background-color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.primary-nav__link:hover {
  color: var(--c-text);
  background: rgba(108, 59, 255, 0.16);
}

.primary-nav__link[aria-current="page"] {
  color: var(--c-pulse);
  border-bottom-color: var(--c-pulse);
  background: linear-gradient(180deg, rgba(41, 231, 214, 0) 30%, rgba(41, 231, 214, 0.12));
}

.nav-rail__cta {
  align-self: center;
  flex: 0 0 auto;
  padding: 10px 18px;
  border: var(--edge) solid var(--c-neon);
  background: rgba(108, 59, 255, 0.18);
  color: var(--c-text);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  white-space: nowrap;
  transition: background-color var(--dur-fast) ease, box-shadow var(--dur-fast) ease, color var(--dur-fast) ease;
}

.nav-rail__cta:hover {
  background: var(--c-neon);
  color: #FFFFFF;
  box-shadow: 0 0 0 1px var(--c-pulse), 0 0 20px rgba(108, 59, 255, 0.6);
}

/* 6.4 移动导航按钮 */
.nav-toggle {
  display: none;
  align-self: center;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: var(--edge) solid var(--c-line-strong);
  background: var(--c-rib);
  color: var(--c-text);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: var(--c-pulse);
  transition: transform var(--dur-fast) ease, opacity var(--dur-fast) ease;
}

.nav-toggle[aria-expanded="true"] { border-color: var(--c-pulse); }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 6.5 滚动进度 */
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 3px;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--c-neon), var(--c-pulse));
  transition: width 120ms linear;
}

/* ---------- 7. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 128px);
  border-top: var(--edge) solid var(--c-line-strong);
  background: linear-gradient(180deg, var(--c-panel) 0%, var(--c-void) 78%);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 0;
  width: min(260px, 44%);
  height: 2px;
  background: linear-gradient(90deg, var(--c-pulse), rgba(41, 231, 214, 0));
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: clamp(24px, 4vw, 64px);
  padding-block: clamp(32px, 5vw, 64px) clamp(20px, 3vw, 40px);
}

.footer-brand__name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 800;
  color: var(--c-text);
  letter-spacing: 0.04em;
}

.footer-brand__desc {
  margin-top: 10px;
  font-size: 13px;
  color: var(--c-dim);
  max-width: 34ch;
}

.footer-brand__meta {
  margin-top: 14px;
  padding-left: 12px;
  border-left: var(--edge) solid var(--c-deep);
  font-size: 13px;
  color: var(--c-mute);
}

.footer-brand__meta .num { color: var(--c-pulse); font-size: 15px; }

.footer-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: clamp(16px, 2.4vw, 36px);
}

.footer-col__title {
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: var(--edge) solid var(--c-rib);
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--c-mute);
}

.footer-col__list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-col__list a {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 14px;
  color: var(--c-dim);
  border-bottom: 1px solid transparent;
  transition: color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.footer-col__list a::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  background: var(--c-deep);
  border: 1px solid var(--c-line-strong);
  transform: rotate(45deg);
}

.footer-col__list a:hover {
  color: var(--c-pulse);
  border-bottom-color: var(--c-pulse);
}

.footer-col__list a:hover::before { background: var(--c-pulse); }

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  padding-block: 18px;
  border-top: var(--edge) solid var(--c-rib);
  font-size: 13px;
  color: var(--c-dim);
}

.footer-contact__item {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.footer-contact__item--wide { flex-basis: 100%; }

.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--c-pulse);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  padding-block: 14px 30px;
  border-top: 1px solid var(--c-line);
  font-size: 12px;
  color: var(--c-mute);
}

.footer-legal__line { letter-spacing: 0.06em; }

/* ---------- 8. 画板 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 3vw, 36px);
  border: var(--edge) solid var(--c-line);
  background: var(--c-panel);
}

.panel--stack {
  box-shadow: var(--shadow-stack);
  border-color: var(--c-line-strong);
}

.panel__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--c-pulse);
}

.panel__eyebrow::before {
  content: "";
  width: 18px;
  height: 8px;
  background: var(--c-deep);
  border: 1px solid var(--c-pulse);
}

.panel__title { margin-bottom: 12px; }

.panel__lede {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--c-dim);
}

.panel__body { margin-top: 20px; }

.panel__note {
  margin-top: 20px;
  padding-left: 14px;
  border-left: var(--edge) solid var(--c-alert);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-dim);
}

/* ---------- 9. 数据带 ---------- */
.data-figure {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  border: var(--edge) solid var(--c-line);
  background: linear-gradient(180deg, rgba(27, 42, 107, 0.35), rgba(11, 16, 36, 0));
}

.data-figure__value {
  font-family: var(--font-mono);
  font-size: clamp(36px, 4.4vw, 72px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-pulse);
  font-variant-numeric: tabular-nums;
}

.data-figure__label {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--c-dim);
}

.data-figure--alert { border-color: rgba(255, 106, 43, 0.5); }
.data-figure--alert .data-figure__value { color: var(--c-alert); }
.data-figure--gold { border-color: rgba(255, 201, 77, 0.45); }
.data-figure--gold .data-figure__value { color: var(--c-gold); }

/* ---------- 10. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 24px;
  border: var(--edge) solid var(--c-line-strong);
  background: var(--c-rib);
  color: var(--c-text);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: background-color var(--dur-fast) ease, color var(--dur-fast) ease, box-shadow var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.btn--primary {
  border-color: var(--c-neon);
  background: var(--c-neon);
  color: #FFFFFF;
}

.btn--primary:hover {
  background: #5A2EE6;
  color: #FFFFFF;
  box-shadow: 0 0 0 2px rgba(41, 231, 214, 0.35);
}

.btn--ghost {
  border-color: var(--c-pulse);
  background: transparent;
  color: var(--c-pulse);
}

.btn--ghost:hover {
  background: rgba(41, 231, 214, 0.12);
  color: var(--c-pulse);
}

.btn--alert {
  border-color: var(--c-alert);
  background: transparent;
  color: var(--c-alert);
}

.btn--alert:hover {
  background: rgba(255, 106, 43, 0.14);
  color: var(--c-alert);
}

/* ---------- 11. 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-mute);
}

.crumbs a { color: var(--c-dim); }
.crumbs a:hover { color: var(--c-pulse); }
.crumbs__sep { color: var(--c-line-strong); }
.crumbs [aria-current="page"] { color: var(--c-gold); }

/* ---------- 12. 正文容器 ---------- */
.prose {
  max-width: 72ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
}

.prose > * + * { margin-top: 1.05em; }
.prose h2 { margin-top: 1.7em; }
.prose h3 { margin-top: 1.5em; color: var(--c-text); }
.prose ul, .prose ol { padding-left: 1.4em; list-style: disc; }
.prose li + li { margin-top: 0.4em; }
.prose a { color: var(--c-pulse); border-bottom: 1px solid rgba(41, 231, 214, 0.45); }
.prose strong { color: var(--c-text); font-weight: 700; }
.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  padding: 2px 6px;
  border: 1px solid var(--c-line);
  background: var(--c-rib);
  color: var(--c-pulse);
}

/* ---------- 13. 旁注 ---------- */
.note {
  padding-left: 14px;
  border-left: var(--edge) solid var(--c-alert);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-dim);
}

.note--inline {
  display: inline;
  padding: 0;
  border: 0;
  font-style: italic;
  color: var(--c-mute);
}

/* ---------- 14. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--c-line-strong);
  background: var(--c-rib);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--c-dim);
}

.tag--cyan { border-color: var(--c-pulse); color: var(--c-pulse); background: rgba(41, 231, 214, 0.09); }
.tag--violet { border-color: var(--c-neon); color: #C9B6FF; background: rgba(108, 59, 255, 0.14); }
.tag--alert { border-color: var(--c-alert); color: var(--c-alert); background: rgba(255, 106, 43, 0.1); }
.tag--gold { border-color: var(--c-gold); color: var(--c-gold); background: rgba(255, 201, 77, 0.1); }

/* ---------- 15. 图片容器基础规则 ---------- */
.media {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: var(--edge) solid var(--c-line-strong);
  background-color: var(--c-panel);
  background-image:
    repeating-linear-gradient(135deg, rgba(41, 231, 214, 0.07) 0 10px, transparent 10px 22px),
    linear-gradient(180deg, rgba(27, 42, 107, 0.4), rgba(5, 7, 15, 0));
}

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

.media--wide { aspect-ratio: 21 / 9; }
.media--square { aspect-ratio: 1 / 1; }

.media__badge {
  position: absolute;
  top: 0;
  left: 0;
  padding: 6px 12px;
  border-right: var(--edge) solid var(--c-line-strong);
  border-bottom: var(--edge) solid var(--c-line-strong);
  background: var(--c-deep);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--c-pulse);
}

.media__caption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-mute);
}

/* ---------- 16. 归档表 ---------- */
.data-table {
  width: 100%;
  font-size: 14px;
}

.data-table th,
.data-table td {
  padding: 11px 14px;
  border-bottom: 1px solid var(--c-line);
  text-align: left;
  vertical-align: top;
}

.data-table thead th {
  border-bottom: var(--edge) solid var(--c-line-strong);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--c-pulse);
}

.data-table tbody tr:hover { background: rgba(27, 42, 107, 0.28); }

.data-table td.num,
.data-table th.num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ---------- 17. 标签页 ---------- */
.tabs { display: flex; flex-direction: column; }

.tabs__list {
  display: flex;
  flex-wrap: wrap;
  border-bottom: var(--edge) solid var(--c-line-strong);
}

.tabs__tab {
  padding: 12px 18px;
  border: var(--edge) solid transparent;
  border-bottom: 0;
  background: transparent;
  color: var(--c-dim);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: color var(--dur-fast) ease, background-color var(--dur-fast) ease, box-shadow var(--dur-fast) ease;
}

.tabs__tab:hover {
  color: var(--c-text);
  background: rgba(108, 59, 255, 0.16);
}

.tabs__tab[aria-selected="true"] {
  color: var(--c-pulse);
  background: rgba(41, 231, 214, 0.09);
  box-shadow: inset 0 -3px 0 var(--c-pulse);
}

.tabs__panel { padding-top: 20px; }

/* ---------- 18. 折叠区 ---------- */
.fold {
  border: var(--edge) solid var(--c-line);
  background: var(--c-panel);
}

.fold[open] { border-color: var(--c-line-strong); }

.fold > summary {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-size: 15px;
  font-weight: 700;
  color: var(--c-text);
}

.fold > summary::-webkit-details-marker { display: none; }

.fold > summary::after {
  content: "＋";
  font-family: var(--font-mono);
  color: var(--c-pulse);
}

.fold[open] > summary::after { content: "－"; }

.fold__body {
  padding: 0 18px 18px;
  font-size: 15px;
  color: var(--c-dim);
}

/* ---------- 19. 入场显现 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity var(--dur) ease, transform var(--dur) ease;
}

.js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 20. 响应式 ---------- */
@media (max-width: 1024px) {
  .grid--asym { grid-template-columns: minmax(0, 1fr); }
  .grid--thirds { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 900px) {
  .brand-strip__note { display: none; }

  .nav-rail__inner {
    justify-content: space-between;
    gap: 12px;
    min-height: 56px;
  }

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

  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    max-height: calc(100vh - 140px);
    overflow-y: auto;
    border-bottom: var(--edge) solid var(--c-line-strong);
    background: var(--c-panel);
    box-shadow: var(--shadow-stack);
  }

  .primary-nav[data-open] { display: block; }

  .primary-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    height: auto;
    padding: 10px var(--gutter) 18px;
    overflow-x: visible;
  }

  .primary-nav__link {
    height: auto;
    padding: 15px 12px;
    border-bottom: 0;
    border-left: 3px solid transparent;
    font-size: 15px;
  }

  .primary-nav__link[aria-current="page"] {
    border-left-color: var(--c-pulse);
    border-bottom-color: transparent;
    background: rgba(41, 231, 214, 0.08);
  }

  .nav-rail__cta { padding: 9px 14px; font-size: 12px; }
}

@media (max-width: 720px) {
  .chip--ghost { display: none; }
  .grid--halves,
  .grid--thirds { grid-template-columns: minmax(0, 1fr); }
  .span-4, .span-6, .span-8 { grid-column: span 12; }
  .footer-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-legal { flex-direction: column; }
}

@media (max-width: 520px) {
  :root { --strip-h: 40px; }
  .brand-mark__sub { display: none; }
  .nav-rail__cta { display: none; }
  .nav-rail__inner { justify-content: flex-start; }
  .nav-toggle { width: 100%; justify-content: space-between; }
  .footer-cols { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 21. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

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