:root {
  --color-surface: #141515;
  --color-surface-alt: #252626;
  --color-surface-deep: #393c3b;
  --color-ink: #cdd6d3;
  --color-ink-soft: #859992;
  --color-ink-muted: #758a83;
  --color-line: #353837;
  --color-primary: #32cd99;
  --color-primary-ink: #111816;
  --color-primary-soft: #182f27;
  --color-accent: #1ae5a1;
  --color-accent-ink: #111816;
  --color-highlight: #153a2e;
  --color-focus: #0df2a5;
  --color-contrast-surface: #f1f3f2;
  --color-contrast-ink: #303634;
  --color-contrast-line: #c7c9c8;
  --color-contrast-accent: #0e7c57;
  --overlay-scrim: linear-gradient(180deg, rgba(241, 243, 242, 0.35) 0%, rgba(241, 243, 242, 0.72) 55%, rgba(241, 243, 242, 0.92) 100%);
  --font-heading: ui-monospace, SFMono-Regular, Menlo, Consolas, "PingFang SC", monospace;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --text-xs: 12.2px;
  --text-sm: 14.6px;
  --text-base: 16px;
  --text-lg: 19.2px;
  --text-xl: 23.0px;
  --text-2xl: 27.6px;
  --text-3xl: 33.2px;
  --text-4xl: 39.8px;
  --text-display: clamp(48px, 9.9vw, 127px);
  --text-figure: clamp(40px, 7.1vw, 91px);
  --weight-heading: 634;
  --weight-body: 400;
  --leading-body: 1.66;
  --leading-heading: 1.16;
  --tracking-heading: 0.011em;
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 5px;
  --radius-pill: 5px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 6px;
  --space-2: 12px;
  --space-3: 18px;
  --space-4: 24px;
  --space-6: 36px;
  --space-8: 48px;
  --container: 1240px;
  --measure: 68ch;
  --gutter: 18px;
  --section-y: 59px;
  --section-y-lg: 83px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 104px;
}

body {
  margin: 0;
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg, video { max-width: 100%; display: block; }
button { font: inherit; color: inherit; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-accent); }
ul, ol { margin: 0; padding: 0; }
hr { border: 0; border-top: 1px dotted var(--color-line); margin: var(--space-4) 0; }

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

.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;
}

/* ========== 中文排版 ========== */
h1, h2, h3, h4, h5 {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-lg); }
h4 { font-size: var(--text-base); }

p { margin: 0 0 var(--space-3); }
p:last-child { margin-bottom: 0; }

strong { font-weight: var(--weight-heading); color: var(--color-ink); }

.mono,
.num,
.index-label,
.status-tag,
.breadcrumbs,
.footer-col-title,
.footer-base,
.brand-sub,
.header-status {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.num {
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.display-title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 0.94;
  letter-spacing: -0.02em;
  margin: 0 0 var(--space-4);
  color: var(--color-ink);
}

.stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

.stat-label {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.index-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin: 0 0 var(--space-2);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
}

.index-label::before {
  content: "";
  width: 16px;
  height: 1px;
  background-color: var(--color-primary);
}

/* ========== 布局 ========== */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--flush-top { padding-top: 0; }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.grid-12 > * { min-width: 0; }

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

.slant-top {
  clip-path: polygon(0 26px, 100% 0, 100% 100%, 0 100%);
  padding-top: calc(var(--section-y) + 26px);
}

.divider-dotted {
  height: 0;
  border: 0;
  border-top: 1px dotted var(--color-line);
  margin: 0;
}

.prose { max-width: var(--measure); }
.prose p { margin-bottom: var(--space-3); }
.prose h2 { margin-top: var(--space-6); }
.prose h3 { margin-top: var(--space-4); }
.prose ul, .prose ol { margin: 0 0 var(--space-3); padding-left: 1.2em; }
.prose li { margin-bottom: var(--space-1); }

/* ========== 面板与标签 ========== */
.panel {
  position: relative;
  padding: var(--space-4);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-1);
}

.panel--deep { background-color: var(--color-surface-deep); }

.panel--glass {
  background-color: color-mix(in srgb, var(--color-surface-alt) 64%, transparent);
  border-color: color-mix(in srgb, var(--color-primary) 26%, var(--color-line));
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.panel--accent-edge {
  border-left: 2px solid var(--color-accent);
}

.panel-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px dotted var(--color-line);
}

.panel-head h3 { margin: 0; }

.status-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 2px var(--space-2);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  border: 1px solid color-mix(in srgb, var(--color-primary) 34%, transparent);
}

.status-tag--accent {
  background-color: color-mix(in srgb, var(--color-accent) 14%, transparent);
  color: var(--color-accent);
  border-color: color-mix(in srgb, var(--color-accent) 40%, transparent);
}

.status-tag--muted {
  background-color: color-mix(in srgb, var(--color-surface-deep) 60%, transparent);
  color: var(--color-ink-soft);
  border-color: var(--color-line);
}

.status-tag .status-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background-color: currentColor;
}

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.05em;
  line-height: 1.2;
  color: var(--color-ink);
  background-color: transparent;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.18s ease, border-color 0.18s ease, color 0.18s ease;
}

.btn:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background-color: var(--color-primary-soft);
}

.btn--primary {
  color: var(--color-primary-ink);
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn--primary:hover {
  color: var(--color-accent-ink);
  background-color: var(--color-accent);
  border-color: var(--color-accent);
}

.btn--ghost { border-style: dotted; }

/* ========== 面包屑 ========== */
.breadcrumbs {
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  list-style: none;
}

.breadcrumbs li + li::before {
  content: "/";
  margin-right: var(--space-2);
  color: var(--color-surface-deep);
}

.breadcrumbs a { color: var(--color-ink-soft); }
.breadcrumbs a:hover { color: var(--color-primary); }
.breadcrumbs [aria-current="page"] { color: var(--color-primary); }

/* ========== 图片容器 ========== */
.media-frame {
  position: relative;
  overflow: hidden;
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.62) contrast(1.14) brightness(0.78);
}

.media-frame__caption {
  margin: 0;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  border-top: 1px dotted var(--color-line);
}

.media-band {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  border-radius: var(--radius-md);
  border: var(--border-thin) solid var(--color-line);
  background-color: var(--color-surface-alt);
}

.media-band__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.media-band__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.6) contrast(1.16) brightness(0.76);
}

.media-band__scrim {
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image: var(--overlay-scrim);
}

.media-band__body {
  position: relative;
  z-index: 2;
  max-width: 54ch;
  padding: calc(var(--section-y) + var(--space-4)) var(--space-6);
  color: var(--color-contrast-ink);
}

.media-band__body h2,
.media-band__body h3 { color: var(--color-contrast-ink); }
.media-band__body p { color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent); }

.media-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--gutter);
}

/* ========== 站点头部 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background-color: color-mix(in srgb, var(--color-surface) 86%, transparent);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px dotted var(--color-line);
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background-color: var(--color-primary);
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: 0 50%;
  pointer-events: none;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -200%;
  z-index: 120;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-primary-ink);
  background-color: var(--color-primary);
  border-radius: var(--radius-sm);
  text-decoration: none;
}

.skip-link:focus { top: var(--space-2); color: var(--color-primary-ink); }

.header-shell {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-2) var(--gutter);
}

.brand-island {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-1) var(--space-3);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: inherit;
  text-decoration: none;
}

.brand:hover { color: inherit; }

.brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: -0.04em;
}

.brand-text { display: block; line-height: 1.25; }

.brand-name {
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: 0.08em;
  color: var(--color-ink);
}

.brand-sub {
  display: block;
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.header-status {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding-left: var(--space-3);
  border-left: 1px dotted var(--color-line);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  white-space: nowrap;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 20%, transparent);
  animation: statusPulse 2.4s ease-in-out infinite;
}

@keyframes statusPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.42; }
}

.nav-island {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}

.nav-list a {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.05em;
  color: var(--color-ink-soft);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: background-color 0.16s ease, color 0.16s ease;
  white-space: nowrap;
}

.nav-list a:hover {
  color: var(--color-ink);
  background-color: var(--color-surface-deep);
}

.nav-list a[aria-current="page"] {
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
}

.nav-list a[aria-current="page"]::before {
  content: "▸ ";
  color: var(--color-accent);
}

.nav-cta {
  display: inline-block;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-primary-ink);
  background-color: var(--color-primary);
  border-radius: var(--radius-sm);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.18s ease, color 0.18s ease;
}

.nav-cta:hover {
  color: var(--color-accent-ink);
  background-color: var(--color-accent);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
  cursor: pointer;
}

.nav-toggle-bars {
  display: grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle-bars span {
  display: block;
  height: 1px;
  background-color: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.site-header[data-open="true"] .nav-toggle {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.site-header[data-open="true"] .nav-toggle-bars span:first-child {
  transform: translateY(2.5px) rotate(45deg);
}

.site-header[data-open="true"] .nav-toggle-bars span:last-child {
  transform: translateY(-2.5px) rotate(-45deg);
}

/* ========== 长内容导航 ========== */
.toc {
  position: sticky;
  top: 104px;
  padding: var(--space-3);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}

.toc-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.toc-list { list-style: none; display: grid; gap: 2px; }

.toc-link {
  display: block;
  padding: var(--space-1) var(--space-2);
  border-left: 2px solid var(--color-line);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: border-color 0.16s ease, color 0.16s ease, background-color 0.16s ease;
}

.toc-link:hover { color: var(--color-ink); background-color: var(--color-surface-deep); }

.toc-link[aria-current="true"] {
  color: var(--color-primary);
  border-left-color: var(--color-focus);
  background-color: var(--color-highlight);
}

.back-to-top {
  position: fixed;
  right: var(--gutter);
  bottom: var(--gutter);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-primary-ink);
  background-color: var(--color-primary);
  border: 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ========== 站点页脚 ========== */
.site-footer {
  position: relative;
  margin-top: var(--section-y-lg);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: 1px dotted var(--color-contrast-line);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 9%;
  width: 132px;
  height: 4px;
  background-color: var(--color-contrast-accent);
  transform: translateY(-100%);
}

.footer-shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--section-y) var(--gutter) var(--space-6);
}

.footer-brand {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4) var(--space-8);
  padding-bottom: var(--space-4);
  border-bottom: 1px dotted var(--color-contrast-line);
}

.footer-identity { max-width: 46ch; }

.footer-brand-name {
  display: inline-block;
  margin-bottom: var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
}

.footer-tagline {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-contrast-accent);
}

.footer-note {
  margin: 0;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
}

.footer-contact {
  display: grid;
  gap: var(--space-1);
  list-style: none;
  min-width: 280px;
}

.footer-contact li {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: var(--space-2);
  align-items: baseline;
}

.footer-contact-key {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-contrast-accent);
}

.footer-contact-val {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  word-break: break-word;
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.footer-col-title {
  margin: 0 0 var(--space-2);
  padding-bottom: var(--space-1);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  line-height: 1.4;
  color: var(--color-contrast-accent);
  border-bottom: 1px dotted var(--color-contrast-line);
}

.footer-links {
  list-style: none;
  display: grid;
  gap: var(--space-1);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}

.footer-links a:hover {
  color: var(--color-contrast-accent);
  border-bottom-color: var(--color-contrast-accent);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-6);
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: 1px dotted var(--color-contrast-line);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}

.footer-copy, .footer-icp { margin: 0; }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  list-style: none;
}

.footer-legal a {
  color: var(--color-contrast-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.footer-legal a:hover { border-bottom-color: var(--color-contrast-accent); }

/* ========== 响应式 ========== */
@media (min-width: 1440px) {
  .container, .header-shell, .footer-shell { padding-inline: var(--space-6); }
}

@media (max-width: 1080px) {
  .header-status { display: none; }
  .nav-list a { padding: var(--space-2); font-size: var(--text-xs); }
}

@media (max-width: 960px) {
  .nav-toggle { display: inline-flex; }

  .nav-island {
    position: absolute;
    top: calc(100% + var(--space-2));
    left: var(--gutter);
    right: var(--gutter);
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-1);
    padding: var(--space-3);
    max-height: 72vh;
    overflow-y: auto;
    border-radius: var(--radius-lg);
  }

  .site-header[data-open="true"] .nav-island { display: flex; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .nav-list a {
    padding: var(--space-3);
    font-size: var(--text-base);
  }

  .nav-cta {
    margin-top: var(--space-2);
    padding: var(--space-3);
    text-align: center;
    font-size: var(--text-sm);
  }

  .toc { position: static; }

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

  .slant-top {
    clip-path: polygon(0 18px, 100% 0, 100% 100%, 0 100%);
    padding-top: calc(var(--section-y) + 18px);
  }
}

@media (max-width: 720px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-12 {
    grid-column: span 6;
  }

  .footer-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-contact { min-width: 0; }
  .footer-contact li { grid-template-columns: 1fr; gap: 0; }
  .footer-base { flex-direction: column; align-items: flex-start; }

  .media-band__body { padding: var(--section-y) var(--space-4); }

  .brand-sub { display: none; }
}

@media (max-width: 420px) {
  .footer-nav { grid-template-columns: 1fr; }
  .back-to-top { right: var(--space-2); bottom: var(--space-2); }
}

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

  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .back-to-top { transform: none; }
}