/* =========================================================
   奥迪棋牌包网 · 共享样式表 /assets/site.css
   赛道仪表盘 × 会员竞技桌面：切角面板、刻度、等宽数字
   ========================================================= */

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

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

body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd, hr {
  margin: 0;
}
ul, ol { padding: 0; list-style: none; }
img, svg, video, canvas { display: block; max-width: 100%; }
img { height: auto; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 色彩 */
  --ink-900: #05080C;
  --ink-800: #0A0F15;
  --panel: #10161D;
  --panel-2: #151D26;
  --line: #232C38;
  --line-soft: rgba(35, 44, 56, .55);
  --text: #C3CEDB;
  --text-dim: #8A97A6;
  --text-strong: #F5F8FC;
  --red: #E11D2E;
  --red-deep: #B2121F;
  --cyan: #17C3E6;
  --blue: #1E4FD8;
  --gold: #FFB020;
  --orange: #FF6A2B;

  /* 渐变 */
  --grad-cool: linear-gradient(120deg, #17C3E6 0%, #1E4FD8 100%);
  --grad-warm: linear-gradient(120deg, #FFB020 0%, #FF6A2B 100%);
  --grad-red: linear-gradient(120deg, #E11D2E 0%, #B2121F 100%);

  /* 尺度 */
  --rail: 260px;
  --header-h: 76px;
  --cut: 12px;
  --cut-sm: 8px;
  --cut-path: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px);
  --cut-path-sm: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);

  /* 动效 */
  --ease: cubic-bezier(.22, .8, .24, 1);

  /* 字体 */
  --font-sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  color: var(--text);
  background-color: var(--ink-900);
  background-image:
    radial-gradient(1100px 620px at 84% -10%, rgba(23, 195, 230, .10), transparent 60%),
    radial-gradient(820px 520px at 2% 6%, rgba(225, 29, 46, .07), transparent 58%),
    repeating-linear-gradient(45deg, rgba(195, 206, 219, .030) 0 1px, transparent 1px 5px),
    repeating-linear-gradient(-45deg, rgba(195, 206, 219, .030) 0 1px, transparent 1px 5px);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.18;
  color: var(--text-strong);
}
h1 { font-size: clamp(34px, 5vw, 64px); }
h2 { font-size: clamp(26px, 3.4vw, 34px); }
h3 { font-size: clamp(20px, 2.2vw, 26px); }
h4 { font-size: 18px; }

p { max-width: 44em; }

strong, b { color: var(--text-strong); font-weight: 700; }
small { font-size: 12px; letter-spacing: .08em; }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
}
.muted { color: var(--text-dim); }
.label-micro {
  font-size: 12px;
  font-weight: 400;
  letter-spacing: .08em;
  color: var(--text-dim);
  line-height: 1.6;
}
.divider {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--line), transparent);
  margin: 28px 0;
}

a.link {
  color: var(--cyan);
  border-bottom: 1px solid rgba(23, 195, 230, .35);
  transition: border-color .2s ease, color .2s ease;
}
a.link:hover { border-bottom-color: var(--cyan); color: #4FDCF5; }

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

::selection { background: rgba(23, 195, 230, .28); color: var(--text-strong); }

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 300;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  color: #FFFFFF;
  background: var(--red);
  clip-path: var(--cut-path-sm);
  transform: translateY(-180%);
  transition: transform .22s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 容器与网格 ---------- */
.shell {
  width: 100%;
  max-width: 1440px;
  margin-inline: auto;
  padding-inline: clamp(18px, 4vw, 40px);
}

.layout {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr);
  gap: clamp(24px, 3vw, 48px);
  align-items: start;
}
.rail { position: sticky; top: calc(var(--header-h) + 24px); }
.rail-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 18px;
  clip-path: var(--cut-path);
}

.grid { display: grid; gap: 20px; }
.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)); }

.btn-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

/* ---------- 6. 面板与图片容器 ---------- */
.panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 22px;
}
.panel--cut { clip-path: var(--cut-path); }
.panel--dark { background: var(--ink-800); }

.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background:
    linear-gradient(150deg, rgba(23, 195, 230, .10), rgba(30, 79, 216, .06) 45%, rgba(16, 22, 29, .9)),
    var(--ink-800);
  border: 1px solid var(--line);
  clip-path: var(--cut-path);
}
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.92) contrast(1.04);
}
.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 14px 18px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text);
  background: linear-gradient(180deg, rgba(5, 8, 12, 0), rgba(5, 8, 12, .92));
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .02em;
  line-height: 1.2;
  white-space: nowrap;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text-strong);
  cursor: pointer;
  clip-path: var(--cut-path-sm);
  transition: background-color .24s ease, border-color .24s ease, color .24s ease, transform .24s var(--ease);
}
.btn:hover { border-color: #33404F; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--primary {
  border-color: transparent;
  background: var(--grad-red);
  color: #FFFFFF;
  box-shadow: 0 10px 26px -14px rgba(225, 29, 46, .9);
}
.btn--primary:hover { background: linear-gradient(120deg, #F3293C, #C3162A); }

.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--text);
}
.btn--ghost:hover { color: var(--cyan); border-color: rgba(23, 195, 230, .55); background: rgba(23, 195, 230, .06); }

.btn--gold {
  border-color: transparent;
  background: var(--grad-warm);
  color: #1A1005;
}
.btn--gold:hover { background: linear-gradient(120deg, #FFC24A, #FF7B3F); }

.btn--block { display: flex; width: 100%; }

/* ---------- 8. 章节标题条 ---------- */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  padding-bottom: 14px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--line);
}
.section-head__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}
.section-head__title {
  margin: 0;
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--text-strong);
}
.section-head__note {
  margin-left: auto;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
}

/* ---------- 9. 数据组件 ---------- */
.stat { display: flex; flex-direction: column; gap: 6px; }
.stat__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(34px, 5vw, 48px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--text-strong);
}
.stat__label {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
}

.ring {
  --p: 0deg;
  position: relative;
  display: grid;
  place-items: center;
  width: 104px;
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  background: conic-gradient(from 180deg, var(--gold) 0deg, var(--orange) var(--p), rgba(35, 44, 56, .8) var(--p) 360deg);
}
.ring::before {
  content: "";
  position: absolute;
  inset: 9px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 1px solid var(--line);
}
.ring__label {
  position: relative;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--gold);
}

/* ---------- 10. 时间轴 ---------- */
.timeline { position: relative; padding-left: 34px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(35, 44, 56, .25));
}
.timeline__item { position: relative; padding-bottom: 26px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__dot {
  position: absolute;
  left: -34px;
  top: 7px;
  width: 15px;
  height: 15px;
  background: var(--ink-900);
  border: 1px solid var(--cyan);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.timeline__meta {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
  margin-bottom: 4px;
}

/* ---------- 11. 折叠面板 ---------- */
.accordion { display: grid; gap: 10px; }
.accordion__item {
  background: var(--panel);
  border: 1px solid var(--line);
  transition: border-color .24s ease;
}
.accordion__item[data-open] { border-color: rgba(23, 195, 230, .45); }
.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 16px 20px;
  border: 0;
  background: transparent;
  color: var(--text-strong);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -.01em;
  text-align: left;
  cursor: pointer;
}
.accordion__trigger::after {
  content: "";
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  border-right: 1.5px solid var(--cyan);
  border-bottom: 1.5px solid var(--cyan);
  transform: rotate(45deg) translateY(-2px);
  transition: transform .28s var(--ease);
}
.accordion__item[data-open] .accordion__trigger::after { transform: rotate(225deg) translateY(-2px); }
.accordion__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows .32s var(--ease);
}
.accordion__item[data-open] .accordion__panel { grid-template-rows: 1fr; }
.accordion__body { overflow: hidden; opacity: 0; transition: opacity .3s ease; }
.accordion__item[data-open] .accordion__body { opacity: 1; }
.accordion__body-inner { padding: 0 20px 20px; }

/* ---------- 12. 标签与面包屑 ---------- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text);
  background: rgba(16, 22, 29, .85);
  border: 1px solid var(--line);
}
.chip--cool { color: var(--cyan); border-color: rgba(23, 195, 230, .42); }
.chip--warm { color: var(--gold); border-color: rgba(255, 176, 32, .42); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
}
.breadcrumb li { display: flex; align-items: center; gap: 8px; }
.breadcrumb li + li::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--line);
}
.breadcrumb a { color: var(--text); transition: color .2s ease; }
.breadcrumb a:hover { color: var(--cyan); }

/* ---------- 13. 正文容器 ---------- */
.prose { max-width: 44em; }
.prose > * + * { margin-top: 1.05em; }
.prose h2 { margin-top: 1.8em; font-size: clamp(20px, 2.4vw, 26px); }
.prose h3 { margin-top: 1.5em; }
.prose p { font-size: 16px; line-height: 1.75; }
.prose ul { display: grid; gap: .55em; padding-left: 1.2em; list-style: none; }
.prose ul li { position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -1.1em;
  top: .68em;
  width: 7px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 14. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(180deg, rgba(5, 8, 12, .97) 0%, rgba(5, 8, 12, .88) 100%);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
}
.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(240px, 42%);
  height: 2px;
  background: var(--grad-cool);
}

.header-inner {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(16px, 2vw, 36px);
  min-height: var(--header-h);
  padding-block: 10px;
}

.header-rule {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 6px;
  pointer-events: none;
  opacity: .75;
  background-image: repeating-linear-gradient(90deg, rgba(35, 44, 56, .95) 0 1px, transparent 1px 13px);
}

/* 品牌字标 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}
.brand__mark {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 26px;
}
.brand__mark i {
  display: block;
  width: 3px;
  border-radius: 1px;
  background: var(--grad-cool);
}
.brand__mark i:nth-child(1) { height: 11px; }
.brand__mark i:nth-child(2) { height: 19px; }
.brand__mark i:nth-child(3) { height: 26px; }
.brand__mark i:nth-child(4) { height: 15px; background: var(--grad-warm); }

.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--text-strong);
}
.brand__sub {
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .16em;
  color: var(--text-dim);
}

/* 主导航 */
.site-nav { display: flex; align-items: center; }

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

.site-nav__list a {
  position: relative;
  display: block;
  padding: 10px 14px;
  font-size: 14px;
  letter-spacing: .02em;
  color: var(--text);
  transition: color .22s ease;
}
.site-nav__list a::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 4px;
  height: 2px;
  background: var(--grad-cool);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .28s var(--ease);
}
.site-nav__list a:hover { color: var(--text-strong); }
.site-nav__list a:hover::after { transform: scaleX(1); }
.site-nav__list a[aria-current="page"] { color: var(--text-strong); font-weight: 600; }
.site-nav__list a[aria-current="page"]::after {
  transform: scaleX(1);
  background: linear-gradient(120deg, var(--red), var(--red-deep));
}

.nav-drawer__extra { display: none; }

.nav-rank {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px;
  margin-bottom: 18px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  clip-path: var(--cut-path);
}
.nav-rank__label { font-size: 12px; letter-spacing: .08em; color: var(--text-dim); }
.nav-rank__value {
  font-size: 20px;
  font-weight: 700;
  background: var(--grad-warm);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.nav-rank__track {
  display: block;
  position: relative;
  height: 4px;
  background: rgba(35, 44, 56, .95);
}
.nav-rank__track i { display: block; height: 100%; background: var(--grad-warm); }
.nav-rank__hint { font-size: 12px; letter-spacing: .06em; color: var(--text-dim); }

/* 右侧操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  color: var(--text-strong);
  font-size: 13px;
  letter-spacing: .08em;
  cursor: pointer;
  clip-path: var(--cut-path-sm);
}
.nav-toggle__bars { display: flex; flex-direction: column; gap: 4px; width: 18px; }
.nav-toggle__bars i {
  display: block;
  height: 2px;
  background: var(--cyan);
  transition: transform .25s var(--ease), opacity .25s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) { transform: translateY(6px) 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(-6px) rotate(-45deg); }

/* 遮罩 */
.nav-scrim { display: none; }

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 120px);
  background: linear-gradient(180deg, rgba(16, 22, 29, .55) 0%, rgba(5, 8, 12, .98) 100%);
  border-top: 1px solid var(--line);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  pointer-events: none;
  opacity: .8;
  background-image: repeating-linear-gradient(90deg, rgba(35, 44, 56, .9) 0 1px, transparent 1px 14px);
}

.footer-shell { padding-block: clamp(34px, 5vw, 60px) 0; }

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.5fr 1.1fr;
  gap: clamp(20px, 3vw, 44px);
}

.footer-col--brand { display: flex; flex-direction: column; gap: 16px; }
.brand--footer .brand__name { font-size: 17px; }

.footer-brief {
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 26em;
}

.footer-heading {
  margin-bottom: 14px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--text-dim);
}

.footer-links li { margin-bottom: 9px; }
.footer-links a {
  position: relative;
  display: inline-block;
  font-size: 14px;
  color: var(--text);
  transition: color .2s ease, padding-left .2s ease;
}
.footer-links a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 1px;
  background: var(--cyan);
  transition: width .22s var(--ease);
}
.footer-links a:hover { color: var(--text-strong); padding-left: 16px; }
.footer-links a:hover::before { width: 10px; }

.footer-contact li {
  display: flex;
  flex-direction: column;
  gap: 3px;
  margin-bottom: 15px;
}
.footer-contact__label {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--text-dim);
}
.footer-contact__value {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text);
  word-break: break-word;
}

.footer-record {
  font-size: 14px;
  color: var(--text-strong);
}
.footer-note {
  margin-top: 10px;
  max-width: 34em;
  font-size: 12px;
  line-height: 1.7;
  color: var(--text-dim);
}

.footer-base {
  margin-top: clamp(28px, 4vw, 48px);
  border-top: 1px solid var(--line);
}
.footer-base__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 20px;
  padding-block: 18px 26px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
}
.footer-base__meta { display: flex; flex-wrap: wrap; gap: 6px 18px; max-width: none; }
.footer-base__line { flex: 1 1 40px; height: 1px; background: var(--line); }
.footer-base__legal { max-width: none; }

/* ---------- 16. 滚动进度与返回顶部 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 140;
  pointer-events: none;
  background: transparent;
}
.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--blue) 55%, var(--red) 100%);
  transition: width .1s linear;
}

.to-top {
  position: fixed;
  left: 20px;
  bottom: 24px;
  z-index: 120;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  font-family: var(--font-mono);
  font-size: 17px;
  line-height: 1;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--line);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  clip-path: var(--cut-path-sm);
  transition: opacity .26s ease, transform .26s var(--ease), visibility .26s, color .2s ease, border-color .2s ease;
}
.to-top[data-visible] { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { color: var(--cyan); border-color: rgba(23, 195, 230, .5); }

/* ---------- 17. 显现动效 ---------- */
html[data-js] [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s ease, transform .5s var(--ease);
}
html[data-js] [data-reveal][data-revealed] {
  opacity: 1;
  transform: none;
}

/* ---------- 18. 响应式 ---------- */
@media (max-width: 1023px) {
  :root { --header-h: 64px; }

  .layout { grid-template-columns: minmax(0, 1fr); }
  .rail { position: static; top: auto; }

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

  .site-header::before { width: min(160px, 55%); }

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

  .header-actions { display: none; }

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

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 130;
    width: min(340px, 86vw);
    display: flex;
    flex-direction: column;
    align-items: stretch;
    padding: calc(var(--header-h) + 28px) 22px 28px;
    overflow-y: auto;
    background: linear-gradient(180deg, #0A0F15 0%, #05080C 100%);
    border-left: 1px solid var(--line);
    transform: translateX(102%);
    transition: transform .34s var(--ease);
  }
  .site-nav[data-open] { transform: translateX(0); }

  .site-nav__list { flex-direction: column; align-items: stretch; gap: 0; }
  .site-nav__list a {
    padding: 14px 4px;
    font-size: 16px;
    border-bottom: 1px solid var(--line-soft);
  }
  .site-nav__list a::after {
    left: 4px;
    right: auto;
    bottom: 8px;
    width: 22px;
  }

  .nav-drawer__extra { display: block; margin-top: 26px; }

  .nav-scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 125;
    background: rgba(5, 8, 12, .72);
    opacity: 0;
    pointer-events: none;
    transition: opacity .3s ease;
  }
  .nav-scrim[data-open] { opacity: 1; pointer-events: auto; }

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

html[data-nav-open] { overflow: hidden; }

@media (max-width: 639px) {
  body { font-size: 15px; }

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

  .panel { padding: 18px; }

  .section-head__note { margin-left: 0; width: 100%; }

  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .footer-base__line { display: none; }
  .footer-base__legal { width: 100%; }

  .to-top { left: 12px; bottom: 16px; width: 40px; height: 40px; }

  .stat__value { font-size: 34px; }
}

/* ---------- 19. 降低动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

  .scroll-progress__bar,
  .to-top,
  .site-nav,
  .nav-scrim,
  .nav-toggle__bars i,
  .accordion__panel,
  .accordion__body,
  .btn { transition: none !important; }

  .btn:hover { transform: none; }
}