/* ============================================================
   电玩平台 · 共享样式表 /assets/site.css
   蓝图网格 + 深夜电玩厅配色
   ============================================================ */

/* ---------- 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, table, th, td { margin: 0; padding: 0; }
ul, ol { 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; padding: 0; cursor: pointer; }
table { border-collapse: collapse; border-spacing: 0; }
input, textarea, select { font: inherit; color: inherit; }

/* ---------- 变量 ---------- */
:root {
  --deep: #070B1A;
  --night: #0E1530;
  --panel: #16203D;
  --line: #24325C;
  --ink: #D7DEEC;
  --ink-2: #9AA7C4;
  --cyan: #35F0D8;
  --violet: #8A6BFF;
  --orange: #FF9A3C;
  --alert: #FF7A5C;
  --ok: #5CE8A0;

  --rail-w: 96px;
  --topbar-h: 60px;
  --maxw: 1200px;

  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
  --sans: "Inter", "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", system-ui, sans-serif;
  --narrow: "Oswald", "Arial Narrow", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;

  --r-sm: 2px;
  --r-md: 4px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

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

body {
  min-height: 100vh;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  background-color: var(--deep);
  background-image:
    radial-gradient(900px 520px at 84% -10%, rgba(138, 107, 255, .20), rgba(138, 107, 255, 0) 70%),
    radial-gradient(720px 420px at 4% 2%, rgba(53, 240, 216, .13), rgba(53, 240, 216, 0) 72%),
    linear-gradient(to right, rgba(36, 50, 92, .42) 1px, rgba(36, 50, 92, 0) 1px),
    linear-gradient(to bottom, rgba(36, 50, 92, .42) 1px, rgba(36, 50, 92, 0) 1px);
  background-size: auto, auto, 96px 96px, 96px 96px;
  background-attachment: fixed, fixed, scroll, scroll;
}

::selection { background: rgba(53, 240, 216, .28); color: #FFFFFF; }

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

/* ---------- 排版 ---------- */
.h1 { font-family: var(--narrow); font-size: 34px; font-weight: 800; line-height: 1.14; letter-spacing: -.5px; }
.h2 { font-family: var(--narrow); font-size: 25px; font-weight: 800; line-height: 1.2; letter-spacing: -.4px; }
.h3 { font-family: var(--narrow); font-size: 19px; font-weight: 700; line-height: 1.3; letter-spacing: -.2px; }
@media (min-width: 900px) {
  .h1 { font-size: 44px; }
  .h2 { font-size: 32px; }
  .h3 { font-size: 22px; }
}

p { max-width: 68ch; }
p + p { margin-top: 14px; }

.mono { font-family: var(--mono); }
.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--cyan);
}
.eyebrow::before { content: ""; width: 18px; height: 1px; background: currentColor; }

.lede { font-size: 17px; line-height: 1.7; color: var(--ink-2); max-width: 60ch; }

.note {
  border-left: 2px solid var(--violet);
  padding: 4px 0 4px 14px;
  font-size: 15px;
  color: var(--ink-2);
}

.rule { height: 1px; width: 100%; background: var(--line); border: 0; }

/* ---------- 布局 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}
@media (min-width: 900px) { .container { padding: 0 40px; } }

.section { padding: 56px 0; }
@media (min-width: 900px) { .section { padding: 88px 0; } }

.stack > * + * { margin-top: 16px; }

.grid { display: grid; gap: 20px; }
.grid--2, .grid--3 { grid-template-columns: 1fr; }
@media (min-width: 720px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
.grid--rail { grid-template-columns: 1fr; }
@media (min-width: 1024px) {
  .grid--rail { grid-template-columns: minmax(0, 1fr) 300px; gap: 40px; }
}

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: -80px;
  left: 12px;
  z-index: 200;
  padding: 10px 16px;
  background: var(--cyan);
  color: #04121A;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  border-radius: var(--r-sm);
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 10px; }

/* ---------- 侧边轨道 / 页头 ---------- */
.site-header { position: relative; z-index: 60; }

.scrim { display: none; }

.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--rail-w);
  z-index: 60;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 18px 10px 20px;
  overflow-y: auto;
  overscroll-behavior: contain;
  background-color: rgba(14, 21, 48, .96);
  border-right: 1px solid var(--line);
}
.rail::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: linear-gradient(to bottom, rgba(53, 240, 216, .12), rgba(53, 240, 216, 0) 36%);
}
.rail::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 5px;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: .85;
  background-image: repeating-linear-gradient(to bottom, var(--line) 0 1px, transparent 1px 48px);
}
.rail > * { position: relative; z-index: 1; }

.rail__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 8px 4px 16px;
  border-bottom: 1px solid var(--line);
}
.rail__brand-mark {
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--cyan);
  text-transform: uppercase;
}
.rail__brand-name {
  font-family: var(--narrow);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: -.2px;
  color: var(--ink);
}

.rail__tagline {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .5px;
  text-align: center;
  color: var(--ink-2);
  max-width: none;
}

.rail__nav { flex: 1 1 auto; }

.rail__list { display: flex; flex-direction: column; gap: 2px; }

.rail__item { display: block; }

.rail__link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 9px 4px;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  transition: border-color .18s var(--ease), background-color .18s var(--ease);
}
.rail__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 3px;
  height: 0;
  background: var(--cyan);
  transform: translateY(-50%);
  transition: height .18s var(--ease);
}
.rail__idx {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 1px;
  color: var(--violet);
  transition: color .18s var(--ease);
}
.rail__label {
  font-size: 12px;
  line-height: 1.3;
  letter-spacing: -.2px;
  color: var(--ink-2);
  transition: color .18s var(--ease);
}
.rail__link:hover { border-color: rgba(53, 240, 216, .35); background: rgba(53, 240, 216, .05); }
.rail__link:hover .rail__label { color: var(--cyan); }
.rail__link:hover .rail__idx { color: var(--cyan); }
.rail__link[aria-current="page"]::before { height: 62%; }
.rail__link[aria-current="page"] .rail__label { color: var(--cyan); font-weight: 700; }
.rail__link[aria-current="page"] .rail__idx { color: var(--cyan); }
.rail__link[aria-current="page"] { border-color: rgba(53, 240, 216, .28); background: rgba(53, 240, 216, .06); }

.rail__foot { display: flex; flex-direction: column; gap: 8px; padding-top: 14px; border-top: 1px solid var(--line); }
.rail__action { width: 100%; }
.rail__support { display: none; width: 100%; }

/* ---------- 移动端顶栏 ---------- */
.topbar { display: none; }

.topbar__brand {
  display: flex;
  flex-direction: column;
  gap: 1px;
  font-family: var(--narrow);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: -.2px;
  color: var(--ink);
}
.topbar__tag {
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 400;
  letter-spacing: 1.6px;
  color: var(--ink-2);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--ink-2);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.nav-toggle__bars { position: relative; display: block; width: 16px; height: 10px; }
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 1px;
  background: currentColor;
  transition: transform .18s var(--ease), top .18s var(--ease);
}
.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { top: 9px; }
.nav-toggle__label { text-transform: uppercase; }
.nav-toggle[aria-expanded="true"] { color: var(--cyan); border-color: rgba(53, 240, 216, .55); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 4.5px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 4.5px; transform: rotate(-45deg); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: rgba(22, 32, 61, .62);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 1px;
  line-height: 1.2;
  white-space: nowrap;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}
.btn:hover { border-color: var(--cyan); color: var(--cyan); }
.btn--ghost { background: transparent; color: var(--ink-2); }
.btn--ghost:hover { background: rgba(53, 240, 216, .07); }
.btn--cyan { border-color: rgba(53, 240, 216, .5); color: var(--cyan); background: rgba(53, 240, 216, .08); }
.btn--cyan:hover { background: rgba(53, 240, 216, .16); }
.btn--action { border-color: rgba(255, 154, 60, .55); color: var(--orange); background: rgba(255, 154, 60, .10); }
.btn--action:hover { border-color: var(--orange); background: rgba(255, 154, 60, .2); color: #FFC08A; }

/* ---------- 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .5px;
  color: var(--ink-2);
}
.crumbs__item { display: inline-flex; align-items: center; gap: 8px; }
.crumbs__link:hover { color: var(--cyan); }
.crumbs__sep { color: var(--line); }
.crumbs__item[aria-current="page"] { color: var(--ink); }

/* ---------- 面板与卡片 ---------- */
.panel {
  padding: 24px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 20px 20px;
  background: linear-gradient(160deg, rgba(22, 32, 61, .92), rgba(14, 21, 48, .92));
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  transition: border-color .18s var(--ease), background-color .18s var(--ease);
}
.card::after {
  content: "";
  position: absolute;
  left: 20px;
  bottom: 0;
  width: 34px;
  height: 2px;
  background: var(--line);
  transition: background-color .18s var(--ease), width .18s var(--ease);
}
.card:hover { border-color: rgba(53, 240, 216, .55); }
.card:hover::after { background: var(--cyan); width: 68px; }
.card__idx {
  font-family: var(--mono);
  font-size: 26px;
  line-height: 1;
  letter-spacing: -1px;
  color: var(--cyan);
}
.card__title { font-family: var(--narrow); font-size: 19px; font-weight: 700; letter-spacing: -.3px; }
.card__text { font-size: 15px; color: var(--ink-2); }
.card__foot {
  margin-top: auto;
  padding-top: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--violet);
}

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1px;
  line-height: 1.6;
  color: var(--ink-2);
}
.tag--cyan { color: var(--cyan); border-color: rgba(53, 240, 216, .45); background: rgba(53, 240, 216, .07); }
.tag--violet { color: var(--violet); border-color: rgba(138, 107, 255, .45); background: rgba(138, 107, 255, .09); }
.tag--orange { color: var(--orange); border-color: rgba(255, 154, 60, .45); background: rgba(255, 154, 60, .09); }

/* ---------- 表格 ---------- */
.tablewrap {
  overflow-x: auto;
  background: rgba(14, 21, 48, .62);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
}
.table { width: 100%; min-width: 520px; font-size: 15px; }
.table caption {
  padding: 14px 16px;
  text-align: left;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--ink-2);
  border-bottom: 1px solid var(--line);
}
.table th,
.table td { padding: 13px 16px; text-align: left; border-bottom: 1px solid var(--line); }
.table th {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--ink-2);
  background: rgba(22, 32, 61, .7);
}
.table tbody tr:last-child td { border-bottom: 0; }
.table td.num { font-family: var(--mono); color: var(--cyan); font-variant-numeric: tabular-nums; }

/* ---------- 步骤条 ---------- */
.steps { display: grid; gap: 14px; }
.steps__item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 18px;
  background: rgba(14, 21, 48, .58);
  border: 1px solid var(--line);
  border-left: 3px solid rgba(53, 240, 216, .5);
  border-radius: var(--r-md);
}
.steps__idx { font-family: var(--mono); font-size: 22px; line-height: 1.2; color: var(--cyan); }
.steps__title { font-family: var(--narrow); font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.steps__text { font-size: 15px; color: var(--ink-2); }

/* ---------- 折叠内容组 ---------- */
.accordion { border-top: 1px solid var(--line); }
.acc { border-bottom: 1px solid var(--line); }
.acc__trigger {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  width: 100%;
  padding: 18px 4px;
  text-align: left;
  transition: background-color .18s var(--ease);
}
.acc__trigger:hover { background: rgba(53, 240, 216, .05); }
.acc__idx {
  flex: none;
  min-width: 26px;
  padding-top: 4px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 1px;
  color: var(--violet);
}
.acc__title { flex: 1 1 auto; font-family: var(--narrow); font-size: 17px; font-weight: 700; line-height: 1.45; }
.acc__trigger[aria-expanded="true"] .acc__title { color: var(--cyan); }
.acc__icon { position: relative; flex: none; width: 14px; height: 14px; margin-top: 7px; }
.acc__icon::before,
.acc__icon::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform .18s var(--ease), opacity .18s var(--ease);
}
.acc__icon::before { left: 0; top: 6px; width: 14px; height: 1.5px; }
.acc__icon::after { left: 6px; top: 0; width: 1.5px; height: 14px; }
.acc__trigger[aria-expanded="true"] .acc__icon::after { transform: scaleY(0); opacity: 0; }
.acc__panel { overflow: hidden; }
html[data-js] .acc__panel { height: 0; transition: height .18s var(--ease); }
.acc__body { padding: 0 4px 20px 44px; font-size: 15px; color: var(--ink-2); }
.acc__body > * + * { margin-top: 12px; }
@media (max-width: 599px) { .acc__body { padding-left: 4px; } }

/* ---------- 图片容器 ---------- */
.media { display: block; }
.media__frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(150deg, #101A38, #070B1A 72%);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
}
.media__frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 74% 18%, rgba(53, 240, 216, .16), rgba(53, 240, 216, 0) 58%),
    radial-gradient(circle at 16% 92%, rgba(138, 107, 255, .2), rgba(138, 107, 255, 0) 60%);
}
.media__img { width: 100%; height: 100%; object-fit: cover; }
.media__cap {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .6px;
  color: var(--ink-2);
}
.media--wide .media__frame { aspect-ratio: 16 / 9; }
.media--square .media__frame { aspect-ratio: 1 / 1; }
.media--tall .media__frame { aspect-ratio: 3 / 4; }

/* ---------- 滚动进度 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 90;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--violet) 66%, var(--orange));
  pointer-events: none;
}

/* ---------- 进入视口显现 ---------- */
[data-reveal] { transition: opacity .55s var(--ease), transform .55s var(--ease); }
html[data-motion-ready] [data-reveal]:not(.is-visible) { opacity: 0; transform: translateY(16px); }

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 72px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 21, 48, .92), rgba(7, 11, 26, 1) 62%);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .5;
  background-image: linear-gradient(to right, rgba(36, 50, 92, .45) 1px, rgba(36, 50, 92, 0) 1px);
  background-size: 96px 100%;
}
.site-footer .container { position: relative; z-index: 1; }

.footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  padding: 56px 0 40px;
}
@media (min-width: 720px) {
  .footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer__brand { grid-column: 1 / -1; }
}
@media (min-width: 1024px) {
  .footer__grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; }
  .footer__brand { grid-column: auto; }
}

.footer__brand-mark {
  font-family: var(--narrow);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -.4px;
  color: var(--ink);
}
.footer__tagline {
  margin-top: 6px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--cyan);
}
.footer__contact { display: grid; gap: 12px; margin-top: 20px; }
.footer__contact-row { display: grid; gap: 2px; }
.footer__contact-label {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 1.6px;
  text-transform: uppercase;
  color: var(--ink-2);
}
.footer__contact-value { font-size: 14.5px; line-height: 1.6; color: var(--ink); word-break: break-word; }

.footer__copy {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0;
  text-align: left;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-word;
  transition: color .18s var(--ease);
}
.footer__copy:hover { color: var(--cyan); }
.footer__copy-hint {
  flex: none;
  padding: 1px 5px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  font-size: 10px;
  letter-spacing: 1px;
  color: var(--ink-2);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.footer__copy-hint::after { content: "复制"; }
.footer__copy[data-copied] .footer__copy-hint { color: var(--ok); border-color: rgba(92, 232, 160, .5); }
.footer__copy[data-copied] .footer__copy-hint::after { content: "已复制"; }

.footer__note { margin-top: 16px; font-size: 13px; line-height: 1.7; color: var(--ink-2); max-width: 42ch; }

.footer__col-title {
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1.6px;
  text-transform: uppercase;
  color: var(--ink-2);
}
.footer__list { display: grid; gap: 10px; }
.footer__link {
  display: inline-flex;
  align-items: center;
  font-size: 14.5px;
  color: var(--ink);
  transition: color .18s var(--ease);
}
.footer__link::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  margin-right: 10px;
  background: var(--line);
  transition: background-color .18s var(--ease);
}
.footer__link:hover { color: var(--cyan); }
.footer__link:hover::before { background: var(--cyan); }

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding: 22px 0 32px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--ink-2);
}
.footer__legal { font-family: var(--mono); font-size: 12px; letter-spacing: .5px; max-width: none; }
.footer__icp { color: var(--ink-2); }
.footer__meta { font-family: var(--mono); font-size: 12px; letter-spacing: .5px; max-width: none; }

/* ---------- 响应式：抽屉导航 ---------- */
@media (max-width: 899px) {
  body { padding-top: var(--topbar-h); }

  .topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--topbar-h);
    z-index: 65;
    padding: 0 16px;
    background: rgba(7, 11, 26, .94);
    border-bottom: 1px solid var(--line);
  }

  .scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 55;
    background: rgba(4, 7, 18, .68);
    opacity: 0;
    visibility: hidden;
    transition: opacity .24s var(--ease), visibility .24s var(--ease);
  }
  .scrim[data-open] { opacity: 1; visibility: visible; }

  .rail {
    top: var(--topbar-h);
    bottom: 0;
    width: min(288px, 76vw);
    gap: 14px;
    padding: 18px 14px 22px;
    transform: translateX(-102%);
    visibility: hidden;
    transition: transform .24s var(--ease), visibility .24s var(--ease);
    box-shadow: 0 24px 60px rgba(0, 0, 0, .55);
  }
  .rail[data-open] { transform: none; visibility: visible; }

  .rail__brand {
    flex-direction: row;
    justify-content: flex-start;
    gap: 12px;
    padding: 0 0 16px;
  }
  .rail__brand-mark { writing-mode: horizontal-tb; letter-spacing: 4px; }
  .rail__brand-name { font-size: 17px; }

  .rail__tagline { text-align: left; font-size: 11px; }

  .rail__link {
    flex-direction: row;
    align-items: baseline;
    gap: 14px;
    padding: 12px 10px;
    border-radius: var(--r-sm);
  }
  .rail__link::before { left: 0; }
  .rail__link[aria-current="page"]::before { height: 56%; }
  .rail__idx { min-width: 22px; font-size: 11px; }
  .rail__label { font-size: 15px; }

  .rail__foot { gap: 10px; }
  .rail__action { padding: 12px 18px; font-size: 13px; }
  .rail__support { display: inline-flex; padding: 13px 18px; font-size: 13px; }
}

@media (min-width: 900px) {
  body { padding-left: var(--rail-w); }
  .rail { transform: none; visibility: visible; }
}

/* ---------- 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;
    scroll-behavior: auto !important;
  }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
}