/* ============================================================
   HAHABET 棋牌 — 共享站点样式 /assets/site.css
   侧边轨道布局 · 32px 精密网格 · 四大内容带配色
   ============================================================ */

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

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

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

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

a { color: inherit; }

button { font: inherit; color: inherit; }

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

table { border-collapse: collapse; }

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

/* ---------- 2. Design tokens ---------- */
:root {
  /* 品牌色：珠宝色分区 */
  --c-void:   #0B0F0E;
  --c-deep:   #0E1F1A;
  --c-panel:  #14261F;
  --c-line:   #1F3A32;
  --c-cyan:   #35E6D2;
  --c-gold:   #FFB940;
  --c-pink:   #FF3D7F;
  --c-violet: #7C5CFF;
  --c-text:   #EAF5F1;
  --c-muted:  #9DB4AD;
  --c-dim:    #3C5C52;

  /* 尺寸 */
  --rail-w:   268px;
  --bar-h:    56px;
  --grid:     32px;
  --wrap-max: 1120px;
  --gutter:   clamp(20px, 4vw, 64px);

  /* 字体 */
  --font-display: "Archivo", "Helvetica Neue", Arial,
                  "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body:    "Noto Sans SC", "Source Han Sans SC", "PingFang SC",
                  "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-data:    "JetBrains Mono", "SFMono-Regular", Menlo, Consolas,
                  "Liberation Mono", monospace;

  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100%;
  background-color: var(--c-void);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: .005em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.06;
  color: var(--c-text);
}

h1 { font-size: clamp(40px, 7vw, 96px); }
h2 { font-size: clamp(28px, 3.4vw, 48px); }
h3 { font-size: clamp(20px, 2vw, 26px); letter-spacing: -.02em; }
h4 { font-size: clamp(17px, 1.5vw, 20px); letter-spacing: -.015em; }

p { max-width: 68ch; }

strong, b { font-weight: 700; color: #fff; }

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

::selection { background-color: var(--c-cyan); color: #04211D; }

/* ---------- 4. 网格背景工具 ---------- */
.gridfield {
  background-image:
    linear-gradient(to right, rgba(31, 58, 50, .6) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 58, 50, .6) 1px, transparent 1px);
  background-size: var(--grid) var(--grid);
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: -140px;
  left: 16px;
  z-index: 200;
  display: inline-block;
  padding: 12px 20px;
  background-color: var(--c-cyan);
  color: #04211D;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .08em;
  text-decoration: none;
  transition: top .18s var(--ease);
}

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

/* ---------- 6. 侧边轨道头部 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 120;
  width: var(--rail-w);
  background-color: var(--c-deep);
  border-right: 1px solid var(--c-line);
  display: flex;
  flex-direction: column;
}

.header-bar { display: none; }

.rail {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  gap: 26px;
  padding: 30px 22px 24px;
  overflow-y: auto;
  overflow-x: hidden;
  background-image:
    linear-gradient(to right, rgba(31, 58, 50, .5) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 58, 50, .5) 1px, transparent 1px);
  background-size: var(--grid) var(--grid);
  scrollbar-width: thin;
  scrollbar-color: var(--c-line) transparent;
}

.rail::-webkit-scrollbar { width: 6px; }
.rail::-webkit-scrollbar-thumb { background-color: var(--c-line); }

/* 品牌字标 */
.brand {
  display: block;
  text-decoration: none;
}

.brand__mark {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 27px;
  line-height: 1;
  letter-spacing: -.035em;
  color: var(--c-text);
}

.brand__sub {
  display: block;
  margin-top: 7px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .42em;
  color: var(--c-cyan);
}

.brand__tagline {
  margin-top: 14px;
  padding-left: 11px;
  border-left: 2px solid var(--c-line);
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-muted);
  max-width: 22ch;
}

.brand--compact { display: none; }

/* 轨道导航 */
.rail-nav { display: block; }

.rail-nav__list { display: flex; flex-direction: column; }

.rail-nav__item { border-top: 1px solid var(--c-line); }

.rail-nav__item:last-child { border-bottom: 1px solid var(--c-line); }

.rail-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 13px 10px 13px 14px;
  text-decoration: none;
  color: var(--c-muted);
  font-size: 15px;
  line-height: 1.3;
  letter-spacing: .02em;
  transition: color .16s var(--ease), background-color .16s var(--ease);
}

.rail-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 2px;
  height: 0;
  background-color: var(--c-cyan);
  transform: translateY(-50%);
  transition: height .2s var(--ease);
}

.rail-nav__idx {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--c-dim);
  transition: color .16s var(--ease);
}

.rail-nav__label { flex: 1 1 auto; }

.rail-nav__link:hover,
.rail-nav__link:focus-visible {
  color: var(--c-text);
  background-image: linear-gradient(90deg, rgba(53, 230, 210, .08), transparent 72%);
}

.rail-nav__link:hover::before,
.rail-nav__link:focus-visible::before { height: 56%; }

.rail-nav__link[aria-current="page"] {
  color: #fff;
  background-image: linear-gradient(90deg, rgba(53, 230, 210, .12), transparent 78%);
}

.rail-nav__link[aria-current="page"]::before { height: 100%; }

.rail-nav__link[aria-current="page"] .rail-nav__idx { color: var(--c-cyan); }

/* 轨道底部 */
.rail__foot {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding-top: 22px;
}

.rail-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.rail-badge {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0;
  font-family: var(--font-data);
  font-size: 11px;
  line-height: 1.4;
  letter-spacing: .1em;
  color: var(--c-muted);
}

.rail-badge__dot {
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  background-color: var(--c-cyan);
  animation: breathe 1.6s var(--ease) infinite;
}

/* 滚动进度 */
.rail-progress {
  position: absolute;
  top: 0;
  right: 0;
  width: 2px;
  height: 100%;
  background-color: transparent;
  pointer-events: none;
}

.rail-progress__fill {
  display: block;
  width: 100%;
  height: calc(var(--p, 0) * 1%);
  background-image: linear-gradient(180deg, var(--c-cyan), var(--c-violet));
}

/* 移动端目录按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  background-color: transparent;
  border: 1px solid var(--c-line);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .2em;
  text-transform: uppercase;
  cursor: pointer;
  transition: border-color .16s var(--ease), color .16s var(--ease);
}

.nav-toggle:hover { border-color: var(--c-cyan); color: var(--c-cyan); }

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 1px;
  width: 100%;
  background-color: currentColor;
  transition: transform .2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(2.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) {
  transform: translateY(-2.5px) rotate(-45deg);
}

@keyframes breathe {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%      { opacity: .32; transform: scale(.72); }
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 16px;
  border: 1px solid var(--c-line);
  border-radius: 0;
  background-color: transparent;
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .04em;
  line-height: 1.4;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .16s var(--ease), color .16s var(--ease),
              border-color .16s var(--ease);
}

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

.btn--cyan {
  background-color: var(--c-cyan);
  border-color: var(--c-cyan);
  color: #04211D;
}
.btn--cyan:hover { background-color: #7FF5E8; border-color: #7FF5E8; }

.btn--gold {
  background-color: transparent;
  border-color: var(--c-gold);
  color: var(--c-gold);
}
.btn--gold:hover { background-color: var(--c-gold); color: #231602; }

.btn--pink {
  background-color: transparent;
  border-color: var(--c-pink);
  color: var(--c-pink);
}
.btn--pink:hover { background-color: var(--c-pink); color: #1A0410; }

.btn--ghost {
  background-color: transparent;
  border-color: var(--c-line);
  color: var(--c-text);
}
.btn--ghost:hover { border-color: var(--c-cyan); color: var(--c-cyan); }

/* ---------- 8. 主页偏移与容器 ---------- */
#main-content {
  display: block;
  min-width: 0;
  margin-left: var(--rail-w);
}

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

.section { padding-block: clamp(48px, 7vw, 96px); }

/* ---------- 9. 网格系统 ---------- */
.grid {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 4fr); }
.grid--offset { grid-template-columns: minmax(0, 5fr) minmax(0, 3fr); }

/* ---------- 10. 面包屑与索引 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.breadcrumb a {
  text-decoration: none;
  color: inherit;
  transition: color .16s var(--ease);
}

.breadcrumb a:hover { color: var(--c-cyan); }

.breadcrumb__sep { color: var(--c-dim); }

.breadcrumb [aria-current="page"] { color: var(--c-text); }

.label {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent, var(--c-muted));
}

.coord {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-muted);
}

.coord__num {
  font-weight: 600;
  color: var(--accent, var(--c-cyan));
}

.section-title {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(20px, 2.8vw, 34px);
}

.section-title h2 { margin: 0; }

.section-title__idx {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--accent, var(--c-cyan));
}

/* ---------- 11. 四大内容带配色 ---------- */
[data-accent="cyan"]   { --accent: var(--c-cyan);   --band: var(--c-cyan); }
[data-accent="gold"]   { --accent: var(--c-gold);   --band: var(--c-gold); }
[data-accent="violet"] { --accent: var(--c-violet); --band: var(--c-violet); }
[data-accent="pink"]   { --accent: var(--c-pink);   --band: var(--c-pink); }

.band--tutorial { --accent: var(--c-cyan);   --band: var(--c-cyan); }
.band--rank     { --accent: var(--c-gold);   --band: var(--c-gold); }
.band--room     { --accent: var(--c-violet); --band: var(--c-violet); }
.band--client   { --accent: var(--c-pink);   --band: var(--c-pink); }

/* ---------- 12. 卡片 ---------- */
.card {
  position: relative;
  display: block;
  padding: clamp(20px, 2.4vw, 30px);
  background-color: var(--c-deep);
  border: 1px solid var(--c-line);
  border-radius: 0;
  text-decoration: none;
  transition: background-color .18s var(--ease);
}

.card::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border: 1px solid var(--accent, var(--c-cyan));
  opacity: 0;
  clip-path: inset(0 100% 100% 0);
  transition: opacity .2s var(--ease), clip-path .32s var(--ease);
}

.card:hover::after,
.card:focus-visible::after {
  opacity: 1;
  clip-path: inset(0 0 0 0);
}

.card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(19px, 1.7vw, 23px);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.25;
  color: var(--c-text);
}

.card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-muted);
}

.card__text + .card__text { margin-top: 10px; }

.card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  align-items: baseline;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--c-line);
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--c-muted);
}

.card__meta b {
  font-weight: 500;
  color: var(--accent, var(--c-cyan));
}

/* ---------- 13. 图片容器 ---------- */
.figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--c-line);
  background-color: var(--c-panel);
}

.figure__media {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  background-color: var(--c-panel);
  background-image:
    linear-gradient(135deg, rgba(53, 230, 210, .10), rgba(124, 92, 255, .12)),
    repeating-linear-gradient(45deg, rgba(31, 58, 50, .9) 0 1px, transparent 1px 12px);
  background-size: cover, 17px 17px;
  color: transparent;
  font-size: 0;
}

.figure--wide .figure__media { aspect-ratio: 21 / 9; }
.figure--tall .figure__media { aspect-ratio: 3 / 4; }
.figure--square .figure__media { aspect-ratio: 1 / 1; }

.figure__cap {
  padding: 11px 14px;
  border-top: 1px solid var(--c-line);
  background-color: var(--c-deep);
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--c-muted);
}

.figure--flush .figure__cap { border-top: 0; }

/* ---------- 14. 数据表格 ---------- */
.table-scroll {
  width: 100%;
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--c-line) transparent;
}

.table-scroll::-webkit-scrollbar { height: 6px; }
.table-scroll::-webkit-scrollbar-thumb { background-color: var(--c-line); }

.data-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  font-size: 14px;
}

.data-table th {
  padding: 11px 14px;
  text-align: left;
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--c-muted);
  border-bottom: 1px solid var(--c-line);
  white-space: nowrap;
}

.data-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--c-line);
  color: var(--c-text);
}

.data-table tbody tr:nth-child(odd) { background-color: var(--c-panel); }
.data-table tbody tr { transition: background-color .16s var(--ease); }
.data-table tbody tr:hover { background-color: rgba(124, 92, 255, .09); }

.data-table .num {
  font-size: 13px;
  color: var(--c-muted);
}

/* ---------- 15. 状态点与文本链接 ---------- */
.dot {
  display: inline-block;
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  background-color: var(--accent, var(--c-cyan));
  vertical-align: middle;
}

.dot--pulse { animation: breathe 1.6s var(--ease) infinite; }

.link {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 230, 210, .4);
  transition: border-color .16s var(--ease), color .16s var(--ease);
}

.link:hover { border-bottom-color: var(--c-cyan); color: #8FF6EC; }

/* ---------- 16. 标签页 ---------- */
.tabs {
  display: flex;
  flex-wrap: wrap;
  margin-bottom: clamp(20px, 2.6vw, 32px);
  border-bottom: 1px solid var(--c-line);
}

.tab {
  position: relative;
  padding: 12px 18px;
  background-color: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--c-muted);
  cursor: pointer;
  transition: color .16s var(--ease), border-color .16s var(--ease),
              background-color .16s var(--ease);
}

.tab:hover {
  color: var(--c-text);
  background-color: rgba(53, 230, 210, .05);
}

.tab[aria-selected="true"] {
  color: var(--c-text);
  border-bottom-color: var(--accent, var(--c-cyan));
  background-image: linear-gradient(180deg, rgba(53, 230, 210, .10), transparent);
}

.tab-panel { animation: panelIn .24s var(--ease); }
.tab-panel[hidden] { display: none; }

@keyframes panelIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: none; }
}

/* ---------- 17. 入场显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .26s var(--ease), transform .26s var(--ease);
}

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

/* ---------- 18. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-left: var(--rail-w);
  background-color: var(--c-deep);
  background-image:
    linear-gradient(to right, rgba(31, 58, 50, .45) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 58, 50, .45) 1px, transparent 1px);
  background-size: var(--grid) var(--grid);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-image: linear-gradient(90deg,
    var(--c-cyan) 0 25%,
    var(--c-gold) 25% 50%,
    var(--c-violet) 50% 75%,
    var(--c-pink) 75% 100%);
}

.footer-inner {
  max-width: var(--wrap-max);
  margin-inline: auto;
  padding: clamp(44px, 6vw, 72px) var(--gutter) 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.3fr;
  gap: 44px 32px;
}

.footer-col { min-width: 0; }

.footer-title {
  margin: 0 0 16px;
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.footer-closing {
  margin-top: 18px;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.4vw, 28px);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.2;
  color: var(--c-text);
  max-width: 14ch;
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-link {
  --band: var(--c-cyan);
  position: relative;
  display: inline-block;
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-text);
  text-decoration: none;
  transition: color .16s var(--ease);
}

.footer-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 6px;
  height: 1px;
  background-color: var(--band);
  transition: width .16s var(--ease);
}

.footer-link:hover { color: var(--band); }
.footer-link:hover::before { width: 10px; }

.footer-link--cyan   { --band: var(--c-cyan); }
.footer-link--gold   { --band: var(--c-gold); }
.footer-link--violet { --band: var(--c-violet); }
.footer-link--pink   { --band: var(--c-pink); }

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

.footer-meta__row {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-muted);
}

.footer-meta__key {
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-dim);
  padding-top: 4px;
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px 28px;
  margin-top: clamp(32px, 5vw, 56px);
  padding-top: 22px;
  border-top: 1px solid var(--c-line);
}

.footer-note {
  font-size: 12px;
  line-height: 1.7;
  color: var(--c-muted);
  max-width: 58ch;
}

.footer-copy {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--c-muted);
}

/* ---------- 19. 响应式 ---------- */
@media (min-width: 961px) and (max-width: 1240px) {
  :root { --rail-w: 226px; }

  .rail { padding: 26px 16px 20px; gap: 22px; }
  .brand__mark { font-size: 23px; }
  .rail-nav__link { font-size: 14px; gap: 10px; }
}

@media (max-width: 1200px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 960px) {
  .site-header {
    top: 0;
    right: 0;
    bottom: auto;
    left: 0;
    width: auto;
    height: auto;
    display: block;
    border-right: 0;
    border-bottom: 1px solid var(--c-line);
    background-color: rgba(11, 15, 14, .94);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
  }

  .header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    min-height: var(--bar-h);
    padding: 10px 16px;
  }

  .brand--compact {
    display: flex;
    align-items: baseline;
    gap: 8px;
  }

  .brand--compact .brand__mark { font-size: 20px; }
  .brand--compact .brand__sub { margin-top: 0; font-size: 10px; letter-spacing: .3em; }

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

  .rail {
    flex: none;
    display: block;
    height: auto;
    max-height: 0;
    padding: 0 16px;
    overflow: hidden;
    border-top: 1px solid transparent;
    background-image: none;
    transition: max-height .3s var(--ease), padding .3s var(--ease),
                border-color .3s var(--ease);
  }

  .rail[data-open] {
    max-height: calc(100vh - var(--bar-h));
    overflow-y: auto;
    padding: 20px 16px 24px;
    border-top-color: var(--c-line);
  }

  .rail__head { display: none; }

  .rail__foot {
    margin-top: 20px;
    padding-top: 0;
  }

  .rail-nav__item:last-child { border-bottom: 0; }

  .rail-nav__link { padding: 12px 8px 12px 12px; }

  .rail-actions { flex-direction: row; }
  .rail-actions .btn { flex: 1 1 0; min-width: 0; padding-inline: 10px; font-size: 13px; }

  .rail-progress {
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    width: auto;
    height: 2px;
  }

  .rail-progress__fill {
    width: calc(var(--p, 0) * 1%);
    height: 100%;
    background-image: linear-gradient(90deg, var(--c-cyan), var(--c-violet));
  }

  #main-content {
    margin-left: 0;
    padding-top: var(--bar-h);
  }

  .site-footer { margin-left: 0; }
}

@media (max-width: 900px) {
  .grid--2,
  .grid--3,
  .grid--4,
  .grid--split,
  .grid--offset { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 640px) {
  .footer-grid { grid-template-columns: 1fr; gap: 34px; }

  .footer-meta__row { grid-template-columns: 1fr; gap: 2px; }
  .footer-meta__key { padding-top: 0; }

  .footer-base { flex-direction: column; align-items: flex-start; }

  .tabs { flex-wrap: nowrap; overflow-x: auto; }
  .tab { white-space: nowrap; }
}

/* ---------- 20. 无障碍与减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
  }

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