:root {
  --color-surface: #fcfcfc;
  --color-surface-alt: #f3f3f3;
  --color-surface-deep: #e6e7e7;
  --color-ink: #424d4d;
  --color-ink-soft: #647272;
  --color-ink-muted: #788687;
  --color-line: #dbdcdc;
  --color-primary: #1f8184;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #ddebeb;
  --color-accent: #da2c25;
  --color-accent-ink: #ffffff;
  --color-highlight: #f6d7d5;
  --color-focus: #e21f18;
  --color-contrast-surface: #152425;
  --color-contrast-ink: #e4e7e7;
  --color-contrast-line: #434f50;
  --color-contrast-accent: #e35e59;
  --overlay-scrim: linear-gradient(180deg, rgba(21, 36, 37, 0.35) 0%, rgba(21, 36, 37, 0.72) 55%, rgba(21, 36, 37, 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: 11.4px;
  --text-sm: 14.3px;
  --text-base: 16px;
  --text-lg: 20.0px;
  --text-xl: 25.0px;
  --text-2xl: 31.2px;
  --text-3xl: 39.1px;
  --text-4xl: 48.8px;
  --text-display: clamp(44px, 9.0vw, 115px);
  --text-figure: clamp(37px, 6.5vw, 83px);
  --weight-heading: 619;
  --weight-body: 400;
  --leading-body: 1.79;
  --leading-heading: 1.27;
  --tracking-heading: 0.023em;
  --radius-sm: 375px;
  --radius-md: 525px;
  --radius-lg: 675px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 0 0 1px rgba(218, 44, 37, 0.35);
  --shadow-2: 0 0 28px rgba(218, 44, 37, 0.35);
  --space-1: 7px;
  --space-2: 14px;
  --space-3: 21px;
  --space-4: 28px;
  --space-6: 42px;
  --space-8: 56px;
  --container: 1120px;
  --measure: 68ch;
  --gutter: 21px;
  --section-y: 81px;
  --section-y-lg: 113px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 132px;
}

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;
}

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

button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }

ul, ol { margin: 0; padding: 0; list-style: none; }
p { margin: 0 0 var(--space-3); }
figure { margin: 0; }

/* ============ 2. 中文排版与标题 ============ */
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);
  text-wrap: balance;
}

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

code, kbd, samp, pre, .mono {
  font-family: var(--font-mono);
  font-size: 0.94em;
  letter-spacing: 0.02em;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  text-underline-offset: 3px;
}

a:hover { text-decoration: underline; }

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

small { font-size: var(--text-xs); }

::selection {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
  border-radius: var(--radius-pill);
}

/* ============ 3. 布局外壳 ============ */
.shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

@media (min-width: 721px) {
  .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; }
}

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

.prose { max-width: var(--measure); }
.prose > p { margin-block: 0 var(--space-3); }
.prose > h2, .prose > h3 { margin-block-start: var(--space-8); }

.bleed-start { margin-inline-start: calc(var(--gutter) * -1); }
.bleed-end { margin-inline-end: calc(var(--gutter) * -1); }

.dot-line {
  height: 0;
  border: 0;
  border-block-start: var(--border-thin) dotted var(--color-line);
  margin-block: var(--space-6);
}

/* ============ 4. 胶囊与按钮 ============ */
.pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  max-width: 100%;
  padding: 7px 21px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  background-color: var(--color-surface);
  color: var(--color-ink-soft);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-body);
  letter-spacing: 0.04em;
  line-height: 1.5;
  white-space: nowrap;
  text-align: center;
  transition: color 0.18s ease, background-color 0.18s ease,
              border-color 0.18s ease, box-shadow 0.18s ease,
              transform 0.18s ease;
}

.pill:hover {
  text-decoration: none;
  border-color: color-mix(in srgb, var(--color-primary) 55%, var(--color-line));
  color: var(--color-primary);
  transform: translateY(-1px);
}

.pill__icon { flex: none; }

.pill--sm { padding: 5px 14px; font-size: var(--text-xs); }

.pill--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.pill--primary:hover {
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
  background-color: color-mix(in srgb, var(--color-primary) 86%, var(--color-contrast-surface));
  box-shadow: 0 0 20px color-mix(in srgb, var(--color-primary) 45%, transparent);
}

.pill--accent {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.pill--accent:hover {
  color: var(--color-accent-ink);
  border-color: var(--color-accent);
  background-color: var(--color-accent);
  box-shadow: var(--shadow-2);
}

.pill--ghost {
  background-color: transparent;
  border-color: var(--color-line);
  color: var(--color-ink-soft);
}
.pill--ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  box-shadow: var(--shadow-1);
}

.pill--search {
  background-color: var(--color-surface);
  border-style: dashed;
  border-color: color-mix(in srgb, var(--color-primary) 55%, transparent);
  color: var(--color-primary);
}
.pill--search:hover {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: 0 0 18px color-mix(in srgb, var(--color-primary) 30%, transparent);
}

.pill--deep {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 55%, transparent);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.pill--deep:hover {
  color: var(--color-primary-ink);
  border-color: var(--color-contrast-accent);
  background-color: color-mix(in srgb, var(--color-contrast-accent) 22%, transparent);
  box-shadow: 0 0 18px color-mix(in srgb, var(--color-contrast-accent) 42%, transparent);
}

.pill.is-copied {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

/* ============ 5. 标签、编号与统计 ============ */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 5px 14px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 45%, transparent);
  border-radius: var(--radius-pill);
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  line-height: 1.6;
  white-space: nowrap;
}

.eyebrow--deep {
  background-color: color-mix(in srgb, var(--color-contrast-accent) 16%, transparent);
  border-color: color-mix(in srgb, var(--color-contrast-accent) 50%, transparent);
  color: var(--color-contrast-accent);
}

.section-index {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-ink-muted);
}

.section-index__num {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  letter-spacing: 0.02em;
  color: var(--color-primary);
}

.figure {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
}

.tag-corner {
  position: absolute;
  inset-block-start: var(--space-2);
  inset-inline-end: var(--space-2);
  z-index: 2;
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  box-shadow: var(--shadow-2);
}

/* ============ 6. 状态灯、状态条与计量 ============ */
.status-lamp {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.status-lamp::before {
  content: "";
  width: 7px;
  height: 7px;
  flex: none;
  border-radius: var(--radius-pill);
  background-color: var(--color-primary);
  box-shadow: 0 0 10px color-mix(in srgb, var(--color-primary) 65%, transparent);
}

.status-lamp--live::before {
  background-color: var(--color-accent);
  box-shadow: 0 0 12px color-mix(in srgb, var(--color-accent) 70%, transparent);
  animation: lamp-breathe 2.6s ease-in-out infinite;
}

.footer-upper .status-lamp { color: var(--color-contrast-ink); }
.footer-upper .status-lamp::before { background-color: var(--color-contrast-accent); }

@keyframes lamp-breathe {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.42; }
}

.status-bar {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 6px;
  border-radius: var(--radius-pill);
  background-color: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
}

.status-bar__seg {
  flex: 1;
  height: 7px;
  border-radius: var(--radius-pill);
  background-color: var(--color-line);
}

.status-bar__seg--on { background-color: var(--color-primary); }
.status-bar__seg--hot {
  background-color: var(--color-accent);
  box-shadow: 0 0 12px color-mix(in srgb, var(--color-accent) 55%, transparent);
}

.status-bar--deep {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 70%, transparent);
  border-color: var(--color-contrast-line);
}
.status-bar--deep .status-bar__seg { background-color: var(--color-contrast-line); }
.status-bar--deep .status-bar__seg--on { background-color: var(--color-contrast-ink); }
.status-bar--deep .status-bar__seg--hot { background-color: var(--color-contrast-accent); }

.meter {
  display: grid;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

.meter__track {
  height: 7px;
  border-radius: var(--radius-pill);
  background-color: var(--color-surface-deep);
  overflow: hidden;
}

.meter__fill {
  display: block;
  height: 100%;
  width: var(--meter-value, 50%);
  border-radius: inherit;
  background-image: linear-gradient(90deg, var(--color-primary), var(--color-contrast-accent));
}

/* ============ 7. 面板、强调与表格 ============ */
.panel {
  position: relative;
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
  border-radius: calc(var(--space-4) / 2);
  background-color: var(--color-surface-alt);
}

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

.panel--deep {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.panel--deep h2,
.panel--deep h3,
.panel--deep h4 { color: var(--color-contrast-ink); }
.panel--deep a { color: var(--color-contrast-accent); }

.panel--deep::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border-radius: inherit;
  background-image:
    linear-gradient(0deg, color-mix(in srgb, var(--color-contrast-line) 55%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--color-contrast-line) 55%, transparent) 1px, transparent 1px);
  background-size: 42px 42px;
  opacity: 0.5;
  -webkit-mask-image: linear-gradient(180deg, #000, transparent);
  mask-image: linear-gradient(180deg, #000, transparent);
}

.quote {
  margin: var(--space-4) 0;
  padding: var(--space-3) var(--space-4);
  border-inline-start: 4px solid var(--color-accent);
  border-start-end-radius: calc(var(--space-4) / 2);
  border-end-end-radius: calc(var(--space-4) / 2);
  background-color: var(--color-highlight);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  text-indent: 0;
}

.quote p:last-child { margin-block-end: 0; }

.spec-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border: var(--border-thin) solid var(--color-line);
  border-radius: calc(var(--space-4) / 2);
  overflow: hidden;
  background-color: var(--color-surface);
  font-size: var(--text-sm);
}

.spec-table th,
.spec-table td {
  padding: var(--space-2) var(--space-3);
  text-align: left;
  vertical-align: top;
  border-block-end: var(--border-thin) dotted var(--color-line);
}

.spec-table thead th {
  background-color: var(--color-surface-deep);
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-soft);
  white-space: nowrap;
}

.spec-table tbody tr:nth-child(even) { background-color: var(--color-surface-alt); }
.spec-table tbody tr:last-child td { border-block-end: 0; }
.spec-table td:first-child {
  font-family: var(--font-heading);
  color: var(--color-ink);
  white-space: nowrap;
}

/* ============ 8. 图片容器与展签 ============ */
.media {
  position: relative;
  overflow: hidden;
  border: var(--border-thin) solid var(--color-line);
  border-radius: calc(var(--space-4) / 2);
  background-color: var(--color-surface-deep);
}

.media img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.media--cut {
  border-radius: calc(var(--space-4) / 2);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.media--overlay::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: var(--overlay-scrim);
}

.media--overlay img { aspect-ratio: 4 / 3; }

.media__caption {
  position: absolute;
  inset-block-end: var(--space-2);
  inset-inline-start: var(--space-2);
  z-index: 2;
  max-width: calc(100% - var(--space-4));
  padding: 5px 14px;
  border-radius: var(--radius-pill);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  line-height: 1.6;
}

.media--overlay .media__caption {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 82%, transparent);
}

/* ============ 9. 面包屑 ============ */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  margin-block: var(--space-4) var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

.crumbs li { display: inline-flex; align-items: center; gap: var(--space-1); }
.crumbs li + li::before {
  content: "/";
  color: var(--color-line);
}
.crumbs a { color: var(--color-ink-soft); }
.crumbs [aria-current="page"] { color: var(--color-primary); }

/* ============ 10. 头部 ============ */
.skip-link {
  position: absolute;
  inset-inline-start: var(--space-2);
  top: calc(var(--space-8) * -1);
  z-index: 120;
  padding: 9px 21px;
  border-radius: var(--radius-pill);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  transition: top 0.18s ease;
}

.skip-link:focus {
  top: var(--space-2);
  text-decoration: none;
  outline-offset: 2px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background-color: var(--color-surface);
  border-block-end: var(--border-thin) dotted var(--color-line);
}

.brand-bar { background-color: var(--color-surface); }

.brand-bar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: 58px;
  padding-block: var(--space-2);
  transition: padding-block 0.2s ease, min-height 0.2s ease;
}

.site-header.is-condensed .brand-bar__inner {
  min-height: 46px;
  padding-block: var(--space-1);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 0;
  color: var(--color-ink);
}

.brand:hover { text-decoration: none; }

.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  min-width: 38px;
  height: 38px;
  padding-inline: var(--space-1);
  border-radius: var(--radius-pill);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  box-shadow: 0 0 18px color-mix(in srgb, var(--color-primary) 55%, transparent);
}

.brand__text { display: grid; gap: 1px; min-width: 0; }

.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.25;
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  white-space: nowrap;
}

.brand__tag {
  display: block;
  max-height: 20px;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  white-space: nowrap;
  transition: max-height 0.2s ease, opacity 0.2s ease;
}

.site-header.is-condensed .brand__tag {
  max-height: 0;
  opacity: 0;
}

.brand-bar__side {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: none;
}

.main-nav {
  position: relative;
  display: block;
  background-color: var(--color-surface-alt);
  border-block-start: var(--border-thin) dotted var(--color-line);
}

.main-nav::before {
  content: "";
  position: absolute;
  inset-inline: 0;
  top: 0;
  height: 3px;
  background-image: linear-gradient(
    90deg,
    var(--color-primary) 0%,
    var(--color-primary) 33%,
    var(--color-accent) 33%,
    var(--color-accent) 66%,
    var(--color-contrast-accent) 66%,
    var(--color-contrast-accent) 100%
  );
}

.main-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-block: var(--space-2);
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 7px 21px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-pill);
  color: var(--color-ink-soft);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  line-height: 1.5;
  white-space: nowrap;
  transition: color 0.18s ease, background-color 0.18s ease,
              border-color 0.18s ease, box-shadow 0.18s ease;
}

.nav-link:hover {
  text-decoration: none;
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 35%, transparent);
}

.nav-link[aria-current="page"] {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: 0 0 20px color-mix(in srgb, var(--color-primary) 45%, transparent);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  padding: 7px 14px;
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-pill);
  background-color: var(--color-surface);
  color: var(--color-primary);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  line-height: 1.5;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  border-radius: var(--radius-pill);
  background-color: currentColor;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  inset-inline-start: 0;
  width: 16px;
  height: 2px;
  border-radius: var(--radius-pill);
  background-color: currentColor;
}

.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }

.nav-toggle[aria-expanded="true"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.scroll-progress {
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: 3px;
  overflow: hidden;
  background-color: color-mix(in srgb, var(--color-line) 60%, transparent);
}

.scroll-progress__fill {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background-image: linear-gradient(90deg, var(--color-primary), var(--color-accent));
}

@media (max-width: 880px) {
  .nav-toggle { display: inline-flex; }

  .main-nav { display: none; }
  .main-nav[data-open="true"] { display: block; }

  .main-nav__inner {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-2);
    padding-block: var(--space-2) var(--space-3);
  }

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

  .nav-link {
    justify-content: flex-start;
    padding: 12px 21px;
    width: 100%;
  }

  .nav-cta { align-self: flex-start; }

  .brand__name { font-size: var(--text-base); }
  .brand-bar__side { gap: var(--space-1); }
  .status-lamp { display: none; }
}

@media (max-width: 520px) {
  .brand__tag { display: none; }
  .brand__mark { min-width: 34px; height: 34px; }
  .pill { padding: 7px 16px; }
}

/* ============ 11. 页脚 ============ */
.site-footer {
  margin-block-start: var(--section-y);
  background-color: var(--color-surface);
}

.footer-upper {
  position: relative;
  padding-block: var(--space-8) var(--space-6);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  overflow: hidden;
}

.footer-upper::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.45;
  background-image:
    linear-gradient(0deg, color-mix(in srgb, var(--color-contrast-line) 60%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--color-contrast-line) 60%, transparent) 1px, transparent 1px);
  background-size: 42px 42px;
  -webkit-mask-image: linear-gradient(180deg, #000, transparent);
  mask-image: linear-gradient(180deg, #000, transparent);
}

.footer-upper::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: 1px;
  background-image: linear-gradient(
    90deg,
    transparent,
    color-mix(in srgb, var(--color-contrast-accent) 85%, transparent),
    transparent
  );
}

.footer-upper__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--space-2);
}

.footer-upper__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  padding-block-end: var(--space-4);
  border-block-end: var(--border-thin) dotted var(--color-contrast-line);
}

.footer-brand {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.footer-index {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  margin-block-start: var(--space-6);
}

.footer-index__group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  min-width: 0;
}

.footer-index__label {
  margin-inline-end: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-contrast-accent);
  white-space: nowrap;
}

.footer-index__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-6);
  margin-block-start: var(--space-6);
  padding-block-start: var(--space-4);
  border-block-start: var(--border-thin) dotted var(--color-contrast-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-ink);
}

.footer-contact__item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  flex-wrap: wrap;
  word-break: break-all;
}

.footer-contact__key { color: var(--color-contrast-accent); letter-spacing: 0.12em; }

.footer-legal {
  background-color: var(--color-surface);
  border-block-start: var(--border-thin) solid var(--color-line);
}

.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-block: var(--space-4);
}

.footer-legal__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

@media (min-width: 960px) {
  .footer-upper__inner { padding-inline-start: var(--space-4); }
  .footer-upper__head { align-items: flex-end; }
}

@media (max-width: 720px) {
  .footer-index { gap: var(--space-4); }
  .footer-legal__inner { justify-content: flex-start; }
}

/* ============ 12. 动效与降级 ============ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .pill:hover { transform: none; }
  .status-lamp--live::before { animation: none; }
}