/* ==========================================================================
   星游官网 /assets/site.css
   共享外壳：双层侧边轨道导航 + 深空页脚 + 基础组件
   ========================================================================== */

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

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

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

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

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

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

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

a { color: inherit; }

/* ---------- 2. Tokens ---------- */
:root {
  --ink-950: #050912;
  --space-800: #0B1430;
  --track-700: #17244C;
  --flame-500: #FF6B2C;
  --flame-300: #FFAA7C;
  --chart-400: #3FD2C7;
  --gold-400: #E7B45C;
  --stone-300: #9BA3B4;
  --terra-500: #B9684D;
  --moss-500: #6F8C5C;
  --ivory-100: #F4F0E6;

  --bg: var(--ink-950);
  --bg-raise: var(--space-800);
  --bg-card: var(--track-700);
  --text: var(--ivory-100);
  --text-dim: var(--stone-300);
  --accent: var(--flame-500);
  --edge: rgba(155, 163, 180, .24);
  --edge-strong: rgba(155, 163, 180, .46);

  --rail-w: 284px;
  --pad-x: clamp(20px, 4.5vw, 64px);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
    "Noto Sans CJK SC", sans-serif;
  --font-serif: "Songti SC", "Source Han Serif SC", "Noto Serif CJK SC",
    Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono",
    "Courier New", monospace;

  --fs-display: clamp(38px, 6vw, 88px);
  --fs-xl: clamp(30px, 4.2vw, 56px);
  --fs-lg: clamp(24px, 2.6vw, 32px);
  --fs-md: 20px;
  --fs-base: 17px;
  --fs-sm: 16px;
  --fs-xs: 13px;
  --fs-2xs: 11px;

  --ease: cubic-bezier(.22, .68, .24, 1);
}

/* ---------- 3. Base ---------- */
body {
  min-height: 100vh;
  padding-inline-start: var(--rail-w);
  background:
    radial-gradient(1200px 700px at 84% -12%, rgba(23, 36, 76, .9), transparent 62%),
    radial-gradient(820px 520px at 6% 106%, rgba(255, 107, 44, .1), transparent 66%),
    var(--ink-950);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.75;
  letter-spacing: .015em;
  -webkit-font-smoothing: antialiased;
}

:focus-visible {
  outline: 2px solid var(--chart-400);
  outline-offset: 3px;
}

#main-content { scroll-margin-top: 96px; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 4. Skip link ---------- */
.skip-link {
  position: fixed;
  inset-block-start: 0;
  inset-inline-start: 0;
  z-index: 300;
  transform: translateY(-150%);
  background: var(--flame-500);
  color: #080c16;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .12em;
  padding: 12px 20px;
  text-decoration: none;
  transition: transform .2s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline-offset: -4px;
}

/* ---------- 5. Header / 品牌轨道 ---------- */
.site-header {
  position: fixed;
  inset-block: 0;
  inset-inline-start: 0;
  width: var(--rail-w);
  z-index: 60;
  display: flex;
  flex-direction: column;
  background: linear-gradient(180deg, #0A1126 0%, #070C1B 46%, #050912 100%);
  border-inline-end: 1px solid var(--edge);
}

.rail-progress {
  position: absolute;
  inset-block: 0;
  inset-inline-start: 0;
  width: 2px;
  background: rgba(155, 163, 180, .14);
  pointer-events: none;
}

.rail-progress__fill {
  display: block;
  width: 100%;
  height: 0;
  background: linear-gradient(180deg, var(--flame-500) 0%, var(--gold-400) 52%, var(--chart-400) 100%);
  transition: height .12s linear;
}

.rail {
  display: flex;
  flex-direction: column;
  gap: 22px;
  min-height: 0;
  height: 100%;
  padding: 26px 22px 18px;
}

/* --- 第一层：品牌说明 + 本月更新 --- */
.rail__meta {
  display: flex;
  flex-direction: column;
  gap: 12px;
  flex: 0 0 auto;
}

.rail__sign {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
}

.rail__mark {
  color: var(--flame-500);
  font-size: 18px;
  line-height: 1;
  transform: translateY(-2px);
}

.rail__name {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: .28em;
  line-height: 1.1;
  color: var(--ivory-100);
}

.rail__tagline {
  max-height: 90px;
  overflow: hidden;
  font-family: var(--font-serif);
  font-size: var(--fs-xs);
  line-height: 1.7;
  letter-spacing: .05em;
  color: var(--stone-300);
  padding-inline-start: 10px;
  border-inline-start: 1px solid var(--edge-strong);
  transition: max-height .32s var(--ease), opacity .24s var(--ease), padding .3s var(--ease);
}

.site-header[data-scrolled] .rail__tagline {
  max-height: 0;
  opacity: 0;
  padding-block: 0;
  border-inline-start-color: transparent;
}

.rail__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* --- 标签 --- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .1em;
  line-height: 1;
  padding: 6px 8px;
  border: 1px solid var(--edge-strong);
  color: var(--stone-300);
  text-transform: uppercase;
  white-space: nowrap;
}

.chip--update {
  color: var(--flame-300);
  border-color: rgba(255, 170, 124, .48);
  background: rgba(255, 107, 44, .1);
}

.chip--stamp {
  color: var(--chart-400);
  border-color: rgba(63, 210, 199, .42);
  background: rgba(63, 210, 199, .08);
}

.chip--gold {
  color: var(--gold-400);
  border-color: rgba(231, 180, 92, .46);
  background: rgba(231, 180, 92, .08);
}

.chip--chart {
  color: var(--chart-400);
  border-color: rgba(63, 210, 199, .42);
}

.chip--moss {
  color: var(--moss-500);
  border-color: rgba(111, 140, 92, .6);
  background: rgba(111, 140, 92, .12);
}

/* --- 移动端开合按钮 --- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border: 1px solid var(--edge-strong);
  color: var(--ivory-100);
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .18em;
  text-transform: uppercase;
  cursor: pointer;
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

.nav-toggle:hover { border-color: var(--flame-500); }

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

.nav-toggle__bars i {
  display: block;
  height: 1px;
  width: 100%;
  background: var(--flame-500);
  font-style: normal;
  transition: transform .24s var(--ease);
}

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

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

/* --- 第二层：主栏目 --- */
.rail__nav {
  display: flex;
  flex-direction: column;
  gap: 12px;
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: rgba(155, 163, 180, .4) transparent;
}

.rail__navlabel {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .26em;
  text-transform: uppercase;
  color: rgba(155, 163, 180, .68);
}

.nav-list {
  display: flex;
  flex-direction: column;
  flex: 0 0 auto;
}

.nav-link {
  position: relative;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  align-items: center;
  gap: 8px;
  padding: 11px 6px 11px 2px;
  border-top: 1px solid rgba(155, 163, 180, .14);
  color: var(--stone-300);
  text-decoration: none;
  transition: color .18s var(--ease), padding-inline-start .18s var(--ease);
}

.nav-list li:last-child .nav-link {
  border-bottom: 1px solid rgba(155, 163, 180, .14);
}

.nav-link__idx {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .1em;
  color: rgba(155, 163, 180, .52);
  transition: color .18s var(--ease);
}

.nav-link__label {
  font-size: 15px;
  letter-spacing: .06em;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--ivory-100);
  padding-inline-start: 8px;
}

.nav-link:hover .nav-link__idx { color: var(--flame-300); }

.nav-link[aria-current="page"] { color: var(--ivory-100); }

.nav-link[aria-current="page"] .nav-link__idx {
  color: var(--flame-500);
  font-weight: 700;
}

.nav-link[aria-current="page"]::before {
  content: "";
  position: absolute;
  inset-block: 5px;
  inset-inline-start: 0;
  width: 2px;
  background: var(--flame-500);
}

.rail__actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--edge);
  flex: 0 0 auto;
}

/* ---------- 6. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 18px;
  border: 1px solid transparent;
  font-size: 15px;
  letter-spacing: .08em;
  line-height: 1.3;
  text-decoration: none;
  cursor: pointer;
  transition: background .2s var(--ease), color .2s var(--ease),
    border-color .2s var(--ease), transform .2s var(--ease);
}

.btn--primary {
  background: var(--flame-500);
  border-color: var(--flame-500);
  color: #0a0d16;
  font-weight: 700;
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: var(--flame-300);
  border-color: var(--flame-300);
}

.btn--ghost {
  background: transparent;
  border-color: var(--edge-strong);
  color: var(--ivory-100);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: var(--chart-400);
  color: var(--chart-400);
}

.btn--quiet {
  padding: 8px 0;
  background: transparent;
  border-color: transparent;
  color: var(--stone-300);
}

.btn--quiet:hover,
.btn--quiet:focus-visible { color: var(--flame-300); }

/* ---------- 7. 轨道底部与返回顶部 ---------- */
.rail__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex: 0 0 auto;
  padding-top: 12px;
  border-top: 1px solid var(--edge);
}

.rail__v {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .16em;
  color: var(--chart-400);
}

.totop {
  padding: 4px 0;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .12em;
  color: var(--stone-300);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity .2s var(--ease), color .2s var(--ease), visibility .2s;
}

.totop[data-visible] {
  opacity: 1;
  visibility: visible;
  color: var(--ivory-100);
}

.totop:hover,
.totop:focus-visible { color: var(--flame-500); }

/* ---------- 8. 星标锚点 ---------- */
.star-anchor {
  position: fixed;
  inset-block-end: 22px;
  inset-inline-end: 22px;
  z-index: 90;
  display: flex;
  flex-direction: column-reverse;
  align-items: flex-end;
  gap: 10px;
}

.star-anchor__toggle {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  background: var(--flame-500);
  border: 1px solid #ffb894;
  color: #080c16;
  cursor: pointer;
  transition: background .2s var(--ease), transform .24s var(--ease);
}

.star-anchor__toggle:hover { background: var(--flame-300); }

.star-anchor__glyph {
  font-size: 22px;
  line-height: 1;
}

.star-anchor[data-open] .star-anchor__toggle { transform: rotate(45deg); }

.star-anchor__menu {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .22s var(--ease), transform .22s var(--ease), visibility .22s;
}

.star-anchor[data-open] .star-anchor__menu {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.star-anchor__menu a {
  display: block;
  padding: 9px 14px;
  background: var(--space-800);
  border: 1px solid var(--edge-strong);
  color: var(--ivory-100);
  font-size: var(--fs-xs);
  letter-spacing: .08em;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color .18s var(--ease), color .18s var(--ease), background .18s var(--ease);
}

.star-anchor__menu a:hover,
.star-anchor__menu a:focus-visible {
  border-color: var(--chart-400);
  color: var(--chart-400);
  background: var(--track-700);
}

/* ---------- 9. Footer ---------- */
.site-footer {
  position: relative;
  display: grid;
  grid-template-columns: minmax(240px, .9fr) minmax(0, 2fr);
  gap: clamp(28px, 5vw, 60px) clamp(24px, 4vw, 56px);
  padding: clamp(42px, 6vw, 84px) var(--pad-x) 26px;
  border-top: 1px solid var(--edge);
  background: linear-gradient(180deg, rgba(11, 20, 48, .92) 0%, rgba(5, 9, 18, 1) 72%);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset-block-start: 0;
  inset-inline-start: var(--pad-x);
  width: 128px;
  height: 2px;
  background: linear-gradient(90deg, var(--flame-500), var(--gold-400));
}

.foot-brand { display: flex; flex-direction: column; gap: 14px; }

.foot-sign {
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: .18em;
  color: var(--ivory-100);
}

.foot-tagline {
  font-family: var(--font-serif);
  font-size: var(--fs-xs);
  line-height: 1.8;
  letter-spacing: .05em;
  color: var(--stone-300);
  max-width: 26ch;
}

.foot-chips { display: flex; flex-wrap: wrap; gap: 6px; }

.foot-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 40px);
}

.foot-col ul { display: flex; flex-direction: column; gap: 9px; }

.foot-col__title {
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--edge);
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  font-weight: 500;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--flame-300);
}

.foot-col a {
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--stone-300);
  text-decoration: none;
  transition: color .18s var(--ease);
}

.foot-col a:hover,
.foot-col a:focus-visible { color: var(--ivory-100); }

.foot-legal {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 18px 32px;
  padding-top: 22px;
  border-top: 1px solid var(--edge);
}

.foot-legal__row {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--stone-300);
  word-break: break-word;
}

.foot-legal__k {
  display: block;
  margin-bottom: 4px;
  font-size: 10px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: rgba(155, 163, 180, .62);
}

.foot-legal__copy {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--ivory-100);
}

.copy-btn {
  padding: 4px 8px;
  border: 1px solid var(--edge-strong);
  color: var(--chart-400);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .14em;
  cursor: pointer;
  transition: color .18s var(--ease), border-color .18s var(--ease), background .18s var(--ease);
}

.copy-btn:hover,
.copy-btn:focus-visible {
  border-color: var(--chart-400);
  background: rgba(63, 210, 199, .12);
}

.copy-btn[data-copied] {
  color: var(--gold-400);
  border-color: rgba(231, 180, 92, .6);
}

.foot-base {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 18px;
  border-top: 1px solid var(--edge);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(155, 163, 180, .82);
}

.foot-base .totop { visibility: visible; opacity: 1; }

/* ---------- 10. 内容骨架 ---------- */
.container {
  width: 100%;
  max-width: 1320px;
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(14px, 2vw, 28px);
}

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-12 { grid-column: span 12; }

.rule-orbit {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg,
    transparent 0%,
    rgba(155, 163, 180, .42) 14%,
    rgba(155, 163, 180, .42) 86%,
    transparent 100%);
}

/* ---------- 11. 排版语气 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .26em;
  text-transform: uppercase;
  color: var(--flame-300);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--flame-500);
}

.display {
  font-size: var(--fs-display);
  font-weight: 800;
  line-height: .96;
  letter-spacing: .02em;
  color: var(--ivory-100);
}

.serif-lede {
  font-family: var(--font-serif);
  font-size: clamp(17px, 1.6vw, 21px);
  line-height: 1.9;
  letter-spacing: .04em;
  color: var(--stone-300);
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: .1em;
}

.section-num {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .26em;
  color: var(--chart-400);
}

/* ---------- 12. 长文 ---------- */
.prose {
  max-width: 68ch;
  color: rgba(244, 240, 230, .86);
  font-size: var(--fs-base);
  line-height: 1.85;
}

.prose h2,
.prose h3 {
  margin-block: 2em .6em;
  font-weight: 700;
  line-height: 1.32;
  letter-spacing: .04em;
  color: var(--ivory-100);
}

.prose h2 { font-size: var(--fs-lg); }
.prose h3 { font-size: var(--fs-md); }

.prose p { margin-block: 0 1.05em; }

.prose ul { list-style: disc; padding-inline-start: 1.4em; margin-block: 0 1.1em; }
.prose ol { list-style: decimal; padding-inline-start: 1.6em; margin-block: 0 1.1em; }
.prose li { margin-block: .35em; }

.prose a {
  color: var(--chart-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 210, 199, .42);
}

.prose a:hover,
.prose a:focus-visible {
  color: var(--flame-300);
  border-bottom-color: var(--flame-300);
}

.prose blockquote {
  margin: 1.6em 0;
  padding-inline-start: 18px;
  border-inline-start: 2px solid var(--flame-500);
  font-family: var(--font-serif);
  color: var(--stone-300);
}

.prose code {
  padding: 1px 5px;
  background: rgba(63, 210, 199, .1);
  color: var(--chart-400);
  font-family: var(--font-mono);
  font-size: .92em;
}

/* ---------- 13. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--stone-300);
}

.breadcrumb li { display: flex; align-items: center; gap: 8px; }

.breadcrumb li + li::before {
  content: "/";
  color: rgba(155, 163, 180, .45);
}

.breadcrumb a { color: var(--stone-300); text-decoration: none; }
.breadcrumb a:hover,
.breadcrumb a:focus-visible { color: var(--flame-300); }
.breadcrumb [aria-current="page"] { color: var(--ivory-100); }

/* ---------- 14. 档案卡片 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background: rgba(23, 36, 76, .55);
  border: 1px solid var(--edge);
}

.card--ink { background: var(--space-800); }

.card--terra {
  background: var(--terra-500);
  border-color: rgba(0, 0, 0, .22);
  color: #FDF7EE;
}

.card--moss {
  background: var(--moss-500);
  border-color: rgba(0, 0, 0, .22);
  color: #08110A;
}

.card__num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .22em;
  color: var(--flame-300);
}

.card--terra .card__num { color: #3A1A10; }
.card--moss .card__num { color: #16240F; }

/* ---------- 15. 图片容器 ---------- */
.figure {
  display: block;
  margin: 0;
  background: var(--space-800);
  border: 1px solid var(--edge);
}

.figure__media {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background:
    repeating-linear-gradient(135deg, rgba(63, 210, 199, .06) 0 1px, transparent 1px 14px),
    radial-gradient(120% 120% at 22% 0%, rgba(23, 36, 76, .95), rgba(5, 9, 18, 1));
}

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

.figure__cap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 6px 12px;
  padding: 9px 12px;
  border-top: 1px solid var(--edge);
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--stone-300);
}

.figure--wide .figure__media { aspect-ratio: 21 / 9; }
.figure--tall .figure__media { aspect-ratio: 4 / 5; }

/* ---------- 16. 响应式：平板与手机 ---------- */
@media (max-width: 1023px) {
  body {
    padding-inline-start: 0;
    font-size: var(--fs-sm);
  }

  .site-header {
    position: sticky;
    inset-block: auto;
    inset-inline-start: auto;
    width: auto;
    border-inline-end: 0;
    border-block-end: 1px solid var(--edge);
    background: #070C1B;
  }

  .rail-progress { display: none; }

  .rail {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "meta meta"
      "nav nav";
    gap: 0 12px;
    height: auto;
    padding: 12px var(--pad-x) 10px;
  }

  .rail__meta {
    grid-area: meta;
    flex-direction: row;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px 12px;
    padding-block-end: 10px;
  }

  .rail__name { font-size: 21px; letter-spacing: .24em; }

  .rail__tagline {
    display: none;
  }

  .rail__chips { margin-inline-start: auto; }

  .nav-toggle {
    display: inline-flex;
    grid-area: meta;
    justify-self: end;
    align-self: start;
    margin-block-start: 2px;
  }

  .rail__nav {
    grid-area: nav;
    flex: none;
    visibility: hidden;
    max-height: 0;
    overflow: hidden;
    gap: 10px;
    transition: max-height .34s var(--ease), visibility 0s linear .34s;
  }

  .rail__nav[data-open] {
    visibility: visible;
    max-height: calc(100dvh - 120px);
    overflow-y: auto;
    transition: max-height .34s var(--ease), visibility 0s;
  }

  .rail__navlabel { padding-block-start: 4px; }

  .nav-link {
    grid-template-columns: 34px minmax(0, 1fr);
    padding-block: 13px;
  }

  .nav-link__label { font-size: var(--fs-sm); white-space: normal; }

  .rail__actions {
    flex-direction: row;
    flex-wrap: wrap;
    margin-top: 0;
    padding-block: 16px 18px;
  }

  .rail__actions .btn { flex: 1 1 160px; }

  .rail__foot { display: none; }

  .site-footer {
    grid-template-columns: minmax(0, 1fr);
    padding-inline: var(--pad-x);
  }

  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }

  .span-3, .span-4, .span-5, .span-6,
  .span-7, .span-8, .span-9 { grid-column: span 6; }

  #main-content { scroll-margin-top: 140px; }
}

@media (max-width: 640px) {
  .container { padding-inline: 18px; }

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

  .foot-sign { letter-spacing: .14em; }

  .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .span-3, .span-4, .span-5, .span-6,
  .span-7, .span-8, .span-9, .span-12 { grid-column: span 2; }

  .star-anchor { inset-block-end: 14px; inset-inline-end: 14px; }
  .star-anchor__toggle { width: 48px; height: 48px; }
  .star-anchor__glyph { font-size: 19px; }

  .banner, .prose { font-size: var(--fs-sm); }
}

/* ---------- 17. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

  .rail-progress__fill { transition: none; }
}