/* =========================================================
   加拿大主页 · 共享外壳样式表 /assets/site.css
   午夜蓝底 + 蓝图网格 + 枫叶红锚点 + 极光绿状态
   ========================================================= */

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

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

body, h1, h2, h3, h4, p, ul, ol, dl, dd, figure, blockquote { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
img, svg { max-width: 100%; }
[hidden] { display: none !important; }

/* ---------- tokens ---------- */
:root {
  --midnight-900: #070B18;
  --midnight-700: #0E1630;
  --blueprint-line: #1E2A4A;
  --maple-red: #E4322B;
  --maple-red-light: #FF6B5E;
  --aurora-green: #3DE0A8;
  --aurora-deep: #1C7F63;
  --silver: #C8D2E0;
  --silver-dim: #8A96A8;
  --paper: #F2F5FA;
  --ink: #10141F;

  --rail-w: 88px;
  --topbar-h: 64px;
  --gutter: clamp(18px, 4vw, 56px);
  --grid-gap: 24px;
  --radius: 2px;

  --font-display: "Source Han Sans SC Heavy", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Source Han Sans SC", "Roboto Condensed", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --font-serif: "Source Han Serif SC Medium", "Noto Serif SC", Georgia, "Songti SC", serif;

  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* ---------- base ---------- */
html { scroll-padding-top: calc(var(--topbar-h) + 16px); }

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

body {
  min-height: 100vh;
  background-color: var(--midnight-900);
  color: var(--silver);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.02em;
  word-break: normal;
  overflow-wrap: break-word;
}

/* 蓝图网格底纹 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(30, 42, 74, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 42, 74, 0.34) 1px, transparent 1px);
  background-size: 24px 24px;
  -webkit-mask-image: radial-gradient(120% 85% at 68% 0%, #000 0%, rgba(0, 0, 0, 0.35) 58%, transparent 100%);
  mask-image: radial-gradient(120% 85% at 68% 0%, #000 0%, rgba(0, 0, 0, 0.35) 58%, transparent 100%);
}

/* 极光环境光 */
body::after {
  content: "";
  position: fixed;
  inset-inline: 0;
  top: -18%;
  height: 78vh;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(46% 58% at 18% 32%, rgba(228, 50, 43, 0.16), transparent 70%),
    radial-gradient(52% 58% at 78% 20%, rgba(61, 224, 168, 0.14), transparent 72%);
  animation: aurora-drift 24s ease-in-out infinite alternate;
}

@keyframes aurora-drift {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to { transform: translate3d(-2%, 2%, 0) scale(1.05); }
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  color: var(--paper);
  line-height: 1.25;
  letter-spacing: 0.02em;
}

h1 { font-size: clamp(30px, 4.4vw, 44px); line-height: 1.18; }
h2 { font-size: clamp(22px, 2.6vw, 28px); }
h3 { font-size: 18px; }

:focus-visible {
  outline: 2px solid var(--aurora-green);
  outline-offset: 3px;
  border-radius: var(--radius);
}

#main-content {
  display: block;
  position: relative;
  z-index: 1;
}

p { max-width: 42em; }

/* ---------- 无损工具类 ---------- */
.wrap {
  width: min(1180px, 100% - (var(--gutter) * 2));
  margin-inline: auto;
}

.mono { font-family: var(--font-mono); letter-spacing: 0.04em; }

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

.sr-only-clip {
  position: fixed;
  top: -1000px;
  left: 0;
  opacity: 0;
  pointer-events: none;
}

.skip-link {
  position: absolute;
  top: 8px;
  left: 8px;
  z-index: 120;
  transform: translateY(-160%);
  padding: 10px 16px;
  background: var(--maple-red);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  border-radius: var(--radius);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 16px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  line-height: 1;
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.btn--primary {
  background: var(--maple-red);
  color: #fff;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}
.btn--primary:hover { background: var(--maple-red-light); color: var(--ink); }

.btn--ghost {
  border-color: var(--blueprint-line);
  color: var(--silver);
}
.btn--ghost:hover { border-color: var(--aurora-green); color: var(--aurora-green); }

.btn--sm { padding: 9px 13px; font-size: 11.5px; }

/* ---------- 顶栏 ---------- */
.site-header { position: relative; z-index: 60; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 55;
  background: linear-gradient(180deg, rgba(7, 11, 24, 0.97), rgba(7, 11, 24, 0.86));
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.topbar__inner {
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 26px);
  min-height: var(--topbar-h);
  padding: 10px var(--gutter);
  border-bottom: 1px solid var(--blueprint-line);
}

.brand { display: flex; flex-direction: column; gap: 2px; min-width: 0; }

.brand__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 16px;
  color: var(--paper);
  letter-spacing: 0.06em;
}

.brand__domain {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--silver-dim);
  letter-spacing: 0.08em;
}

.path-bar {
  display: none;
  align-items: center;
  gap: 8px;
  padding-left: 16px;
  border-left: 1px solid var(--blueprint-line);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--silver-dim);
}

.path-bar__value { color: var(--maple-red-light); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

.utility-links { display: none; gap: 18px; font-size: 13px; }

.utility-links a {
  display: inline-block;
  padding-block: 4px;
  color: var(--silver-dim);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.utility-links a:hover {
  color: var(--paper);
  border-bottom-color: var(--maple-red);
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 4px;
  width: 42px;
  height: 42px;
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  transition: border-color 0.2s var(--ease);
}
.nav-toggle:hover { border-color: var(--aurora-green); }

.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--silver);
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}

body.is-nav-open .nav-toggle__bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
body.is-nav-open .nav-toggle__bar:nth-child(2) { opacity: 0; }
body.is-nav-open .nav-toggle__bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.scroll-progress {
  position: relative;
  height: 2px;
  overflow: hidden;
  background: rgba(30, 42, 74, 0.85);
}

.scroll-progress__fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--maple-red), #B0453F 45%, var(--aurora-green));
  transition: width 0.12s linear;
}

/* ---------- 返回本区起点 ---------- */
.back-path {
  position: fixed;
  right: clamp(12px, 3vw, 32px);
  top: calc(var(--topbar-h) + 14px);
  z-index: 58;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 13px;
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  background: rgba(14, 22, 48, 0.92);
  color: var(--silver-dim);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.back-path:hover { border-color: var(--aurora-green); color: var(--aurora-green); }
.back-path__mark { color: var(--maple-red-light); }

/* ---------- 轨道导航（移动端先写抽屉形态） ---------- */
.rail-nav {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 70;
  display: flex;
  flex-direction: column;
  width: min(320px, 86vw);
  padding: 20px 0 16px;
  background: var(--midnight-700);
  border-right: 1px solid var(--blueprint-line);
  overflow-y: auto;
  overscroll-behavior: contain;
  transform: translateX(-102%);
  transition: transform 0.28s var(--ease);
}

.rail-nav[data-open] { transform: translateX(0); }

.rail-nav__mark {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 16px 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--blueprint-line);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--silver-dim);
}
.rail-nav__mark strong {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.rail-nav__list { padding: 0 14px; }

.rail-nav__item { border-bottom: 1px solid rgba(30, 42, 74, 0.7); }

.rail-nav__link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 6px;
  color: var(--silver);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: 0.04em;
}

.rail-nav__code {
  min-width: 36px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--silver-dim);
}

.rail-nav__label { color: inherit; }

.rail-nav__link:hover { color: #fff; }
.rail-nav__link:hover .rail-nav__code { color: var(--maple-red-light); }

.rail-nav__link[aria-current="page"] { color: #fff; }
.rail-nav__link[aria-current="page"] .rail-nav__label { color: var(--maple-red-light); }
.rail-nav__link[aria-current="page"] .rail-nav__code { color: var(--maple-red-light); }

.rail-nav__note {
  margin: auto 16px 0;
  padding-top: 14px;
  border-top: 1px solid var(--blueprint-line);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--silver-dim);
}

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 65;
  background: rgba(7, 11, 24, 0.74);
  -webkit-backdrop-filter: blur(2px);
  backdrop-filter: blur(2px);
}

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: 96px;
  background: var(--midnight-700);
  border-top: 1px solid var(--blueprint-line);
}

.footer-band {
  height: 6px;
  background: linear-gradient(90deg, var(--maple-red) 0%, #7A2C48 38%, var(--aurora-deep) 70%, var(--aurora-green) 100%);
  opacity: 0.92;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
  padding: 46px 0 34px;
}

.footer-col { position: relative; }

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--paper);
}
.footer-col__title::before {
  content: "";
  display: block;
  width: 6px;
  height: 6px;
  background: var(--aurora-green);
}
.footer-col--guide .footer-col__title::before { background: var(--maple-red); }

.footer-guide a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 0;
  font-size: 14px;
  color: var(--silver);
  border-bottom: 1px dashed rgba(30, 42, 74, 0.85);
  transition: color 0.2s var(--ease);
}
.footer-guide a:hover { color: var(--paper); }
.footer-guide a:hover .footer-guide__code { color: var(--maple-red-light); }

.footer-guide__code {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--silver-dim);
}

.footer-contact { display: grid; gap: 10px; }

.footer-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  font-size: 13.5px;
}

.footer-contact__label {
  min-width: 58px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--silver-dim);
}

.footer-contact__value {
  color: var(--silver);
  font-size: 13px;
}

.copy-btn {
  padding: 3px 8px;
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--silver-dim);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease), background-color 0.2s var(--ease);
}
.copy-btn:hover { border-color: var(--aurora-green); color: var(--aurora-green); }
.copy-btn.is-done {
  background: var(--aurora-green);
  border-color: var(--aurora-green);
  color: var(--midnight-900);
}

.footer-note {
  margin-top: 12px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--silver-dim);
}

.footer-legal { display: grid; gap: 9px; }
.footer-legal a {
  font-size: 13.5px;
  color: var(--silver);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.footer-legal a:hover {
  color: var(--maple-red-light);
  border-bottom-color: var(--maple-red);
}

.footer-bottom {
  border-top: 1px solid var(--blueprint-line);
  background: rgba(7, 11, 24, 0.5);
}

.footer-bottom__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 16px 0;
}

.footer-brand {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  max-width: none;
}

.footer-brand__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--paper);
}

.footer-brand__domain,
.footer-meta {
  font-size: 11.5px;
  color: var(--silver-dim);
}

/* ---------- 通用内容组件 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--grid-gap);
}

.col-3, .col-4, .col-6, .col-8, .col-12 { grid-column: span 12; }

.divider {
  height: 1px;
  background: var(--blueprint-line);
  border: 0;
  margin: 32px 0;
}

.color-band {
  height: 6px;
  background: linear-gradient(90deg, var(--maple-red), var(--aurora-green));
  border-radius: 1px;
}
.color-band--soft {
  background: linear-gradient(90deg, rgba(228, 50, 43, 0.55), rgba(61, 224, 168, 0.5));
}

.section-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 26px;
}

.section-head__code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--maple-red-light);
}

.section-head__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3vw, 28px);
  line-height: 1.3;
  color: var(--paper);
}

.section-head__desc {
  max-width: 40em;
  font-size: 14px;
  color: var(--silver-dim);
}

.mark-code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--silver-dim);
}
.mark-code--red { color: var(--maple-red-light); }
.mark-code--green { color: var(--aurora-green); }

.lede {
  max-width: 40em;
  font-size: 17px;
  line-height: 1.75;
  color: var(--silver);
}

.serif-accent {
  font-family: var(--font-serif);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.prose {
  max-width: 40em;
  font-size: 16px;
  line-height: 1.75;
  color: var(--silver);
}
.prose p + p { margin-top: 1.1em; }
.prose h3 { margin: 1.8em 0 0.6em; }
.prose ul { display: grid; gap: 0.5em; margin-top: 0.8em; }
.prose li { padding-left: 1.2em; position: relative; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background: var(--aurora-green);
}

.card {
  position: relative;
  padding: 22px;
  background: var(--midnight-700);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
}

.card--paper {
  background: var(--paper);
  border-color: #D7DEE9;
  color: var(--ink);
}
.card--paper .card__title,
.card--paper .card__code { color: var(--ink); }

.card--red { border-left: 3px solid var(--maple-red); }
.card--green { border-left: 3px solid var(--aurora-green); }

.card__code {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--silver-dim);
}

.card__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.45;
  color: var(--paper);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px;
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--silver-dim);
}
.tag--red { color: var(--maple-red-light); border-color: rgba(228, 50, 43, 0.5); }
.tag--green { color: var(--aurora-green); border-color: rgba(61, 224, 168, 0.45); }

/* ---------- 图片容器基础规则 ---------- */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  isolation: isolate;
  background: linear-gradient(135deg, #0E1630 0%, #12203C 46%, #0B1A2A 100%);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
}

.img-frame::before,
.img-frame::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--aurora-deep);
  pointer-events: none;
}
.img-frame::before { top: 8px; left: 8px; border-right: 0; border-bottom: 0; }
.img-frame::after { right: 8px; bottom: 8px; border-left: 0; border-top: 0; }

.img-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame--16x9 { aspect-ratio: 16 / 9; }
.img-frame--4x3 { aspect-ratio: 4 / 3; }
.img-frame--1x1 { aspect-ratio: 1 / 1; }
.img-frame--tall { aspect-ratio: 3 / 4; }

.img-frame--fill { position: absolute; inset: 0; }

.img-frame--aurora {
  background:
    linear-gradient(120deg, rgba(228, 50, 43, 0.24), rgba(61, 224, 168, 0.2) 58%, rgba(14, 22, 48, 0.92)),
    var(--midnight-700);
}

.img-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 10px 14px;
  font-size: 12px;
  color: var(--silver);
  background: linear-gradient(180deg, transparent, rgba(7, 11, 24, 0.92));
}

/* ---------- 断点 ---------- */
@media (min-width: 560px) {
  .col-3 { grid-column: span 6; }
  .col-4 { grid-column: span 6; }
  .col-6 { grid-column: span 12; }
  .col-8 { grid-column: span 12; }
}

@media (min-width: 760px) {
  .path-bar { display: flex; }
  .utility-links { display: flex; }
  .nav-toggle { display: none; }

  .footer-grid {
    grid-template-columns: 1.05fr 1.25fr 0.9fr;
    gap: 40px;
  }
  .footer-col + .footer-col {
    padding-left: 32px;
    border-left: 1px solid var(--blueprint-line);
  }
  .footer-col + .footer-col::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 0;
    width: 1px;
    height: 10px;
    background: var(--aurora-green);
  }

  .col-3 { grid-column: span 3; }
  .col-4 { grid-column: span 4; }
  .col-6 { grid-column: span 6; }
  .col-8 { grid-column: span 8; }
}

@media (min-width: 900px) {
  body { padding-left: var(--rail-w); }

  .rail-nav {
    width: var(--rail-w);
    transform: none;
    transition: none;
    padding: 18px 0 14px;
  }

  .rail-nav__mark {
    flex-direction: column;
    align-items: center;
    gap: 4px;
    margin: 0 10px 14px;
    padding-bottom: 12px;
  }
  .rail-nav__mark strong { font-size: 14px; letter-spacing: 0.02em; }

  .rail-nav__list {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 0 8px;
  }

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

  .rail-nav__link {
    position: relative;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 11px 6px;
    font-size: 12.5px;
    color: var(--silver-dim);
    transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
  }

  .rail-nav__link:hover { background: rgba(30, 42, 74, 0.55); }

  .rail-nav__label {
    writing-mode: vertical-rl;
    text-orientation: upright;
    line-height: 1.05;
    letter-spacing: 0.16em;
    font-family: var(--font-display);
    font-weight: 800;
  }

  .rail-nav__link[aria-current="page"]::before {
    content: "";
    position: absolute;
    left: 0;
    top: 6px;
    bottom: 6px;
    width: 2px;
    background: var(--maple-red);
  }

  .rail-nav__note {
    margin: auto 10px 0;
    text-align: center;
    letter-spacing: 0.06em;
  }

  .nav-scrim { display: none; }
}

@media (min-width: 960px) {
  .img-frame--16x9 { aspect-ratio: 21 / 9; }
}

@media (max-height: 780px) and (min-width: 900px) {
  .rail-nav__link { padding: 8px 6px; gap: 6px; }
}

@media (max-width: 899px) {
  body.is-nav-open { overflow: hidden; }
  .topbar .btn--primary { display: none; }
}

@media (max-width: 480px) {
  :root { --topbar-h: 60px; }
  .brand__domain { font-size: 10px; }
  .footer-bottom__inner { justify-content: flex-start; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  body::after { animation: none; }
  .rail-nav,
  .btn,
  .nav-toggle,
  .nav-toggle__bar,
  .copy-btn,
  .skip-link,
  .scroll-progress__fill,
  .back-path,
  .utility-links a,
  .footer-legal a { transition: none; }
  .scroll-progress__fill { transition: none; }
}