:root {
  --color-surface: #fafafa;
  --color-surface-alt: #f1f1f2;
  --color-surface-deep: #e4e5e6;
  --color-ink: #444950;
  --color-ink-soft: #686e79;
  --color-ink-muted: #777e88;
  --color-line: #d9dadb;
  --color-primary: #2f6ed0;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dee6f4;
  --color-accent: #1019ef;
  --color-accent-ink: #ffffff;
  --color-highlight: #d0d2f8;
  --color-focus: #030dfc;
  --color-contrast-surface: #171f2a;
  --color-contrast-ink: #e4e5e7;
  --color-contrast-line: #444b54;
  --color-contrast-accent: #7479f6;
  --overlay-scrim: linear-gradient(180deg, rgba(23, 31, 42, 0.35) 0%, rgba(23, 31, 42, 0.72) 55%, rgba(23, 31, 42, 0.92) 100%);
  --font-heading: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans 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(54px, 11.2vw, 143px);
  --text-figure: clamp(45px, 8.0vw, 103px);
  --weight-heading: 609;
  --weight-body: 400;
  --leading-body: 1.82;
  --leading-heading: 1.2;
  --tracking-heading: 0.004em;
  --radius-sm: 14px;
  --radius-md: 17px;
  --radius-lg: 20px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 6px 18px rgba(68, 73, 80, 0.08);
  --shadow-2: 0 18px 44px rgba(68, 73, 80, 0.14);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1240px;
  --measure: 69ch;
  --gutter: 32px;
  --section-y: 86px;
  --section-y-lg: 120px;
}

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

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

body {
  --rail-w: 200px;
  --topbar-h: 56px;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --glass: color-mix(in srgb, var(--color-surface) 74%, transparent);
  --glass-strong: color-mix(in srgb, var(--color-surface) 90%, transparent);
  --edge: color-mix(in srgb, var(--color-line) 78%, var(--color-surface));
  --tint: color-mix(in srgb, var(--color-surface) 42%, transparent);
  --hair: color-mix(in srgb, var(--color-primary) 14%, transparent);
  --color-heading: color-mix(in srgb, var(--color-ink) 42%, var(--color-contrast-surface));

  margin: 0;
  padding: 0;
  padding-top: var(--topbar-h);
  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;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 彩色底纹层：玻璃面板浮在它之上 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(58% 38% at 6% -8%, color-mix(in srgb, var(--color-primary) 28%, transparent) 0%, transparent 72%),
    radial-gradient(46% 34% at 98% 2%, color-mix(in srgb, var(--color-accent) 16%, transparent) 0%, transparent 70%),
    linear-gradient(180deg,
      var(--color-primary-soft) 0%,
      color-mix(in srgb, var(--color-primary-soft) 34%, var(--color-surface)) 34%,
      var(--color-surface) 60%);
}

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

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

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

a { color: inherit; }

button { font: inherit; color: inherit; }

hr { border: 0; }

/* ================= CJK typography ================= */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-heading);
  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); }

p { text-wrap: pretty; }

.display-type {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 0.92;
  letter-spacing: -0.03em;
  color: var(--color-heading);
  word-break: keep-all;
}

.hero-figure {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 0.94;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  font-variant-numeric: tabular-nums;
}

a.link-plain {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

/* ================= layout ================= */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section--flush-top { padding-block-start: 0; }

.section--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid var(--color-contrast-line);
}

.grid {
  display: grid;
  gap: var(--space-4);
}

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

.grid--2 { grid-template-columns: 1fr; }

.rule {
  height: 1px;
  background: var(--color-line);
  margin-block: var(--section-y);
}

.rule--tight { margin-block: var(--space-4); }

/* ================= 玻璃层叠 ================= */
.layer {
  position: relative;
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
}

.layer--tint {
  background:
    linear-gradient(140deg,
      var(--color-primary-soft) 0%,
      color-mix(in srgb, var(--color-highlight) 52%, var(--color-surface)) 58%,
      color-mix(in srgb, var(--color-accent) 10%, var(--color-surface)) 100%);
  border-color: var(--edge);
}

.layer--accent {
  background:
    linear-gradient(150deg,
      color-mix(in srgb, var(--color-accent) 88%, var(--color-primary)) 0%,
      color-mix(in srgb, var(--color-primary) 72%, var(--color-contrast-surface)) 100%);
  border-color: color-mix(in srgb, var(--color-accent) 55%, var(--color-surface));
  color: var(--color-accent-ink);
}

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

.panel {
  position: relative;
  background: var(--glass);
  border: var(--border-thin) solid var(--edge);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  -webkit-backdrop-filter: blur(16px) saturate(1.15);
  backdrop-filter: blur(16px) saturate(1.15);
  padding: var(--space-3);
  color: var(--color-ink);
}

.panel--lg {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-2);
  padding: var(--space-4);
}

.panel--flush { padding: 0; }

.panel--deep {
  background: color-mix(in srgb, var(--color-contrast-surface) 74%, transparent);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.panel__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  margin-bottom: var(--space-3);
}

.panel__head > :first-child { margin-inline-end: auto; }

.panel__body > * + * { margin-top: var(--space-3); }

.panel__foot {
  margin-top: var(--space-3);
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.panel--deep .panel__head,
.panel--deep .panel__foot { border-color: var(--color-contrast-line); }
.panel--deep .panel__foot { color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent); }

/* ================= buttons / tags ================= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid transparent;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms var(--ease-out), background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: color-mix(in srgb, var(--color-primary) 70%, var(--color-contrast-surface));
}

.btn--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border-color: color-mix(in srgb, var(--color-accent) 70%, var(--color-contrast-surface));
}

.btn--ghost {
  background: var(--glass);
  color: var(--color-ink);
  border-color: var(--color-line);
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 12px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid var(--color-line);
  background: var(--glass);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  font-variant-numeric: tabular-nums;
}

.tag--primary {
  background: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 32%, transparent);
  color: var(--color-primary);
}

.tag--accent {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.tag--outline {
  background: transparent;
  border-color: color-mix(in srgb, var(--color-ink-muted) 45%, transparent);
  color: var(--color-ink-muted);
}

/* ================= 强调机制：引号 + 缩进 ================= */
.quote {
  margin-block: var(--space-4);
  padding-inline-start: var(--space-3);
  border-inline-start: 3px solid var(--color-accent);
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-heading);
  font-weight: var(--weight-heading);
}

.quote::before {
  content: "“";
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  line-height: 1;
  color: var(--color-accent);
  margin-bottom: var(--space-1);
}

.quote__source {
  display: block;
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  font-weight: var(--weight-body);
  color: var(--color-ink-muted);
}

/* ================= 数据组件 ================= */
.stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat__value {
  font-family: var(--font-mono);
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

.stat__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--glass);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
}

.data-table th,
.data-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: var(--border-thin) solid var(--color-line);
  white-space: nowrap;
}

.data-table th {
  background: var(--color-primary-soft);
  color: var(--color-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
}

.data-table tbody tr:nth-child(even) { background: var(--color-surface-deep); }
.data-table tbody tr:last-child td { border-bottom: 0; }

/* 页签 */
.tabs { display: block; }

.tabs__bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  padding-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.tabs__btn {
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid var(--color-line);
  background: var(--glass);
  color: var(--color-ink-soft);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}

.tabs__btn[aria-selected="true"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.tab-panel { padding-top: var(--space-3); }
.tab-panel[hidden] { display: none; }

/* 图片区块 */
.media-block {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid var(--edge);
  background-color: var(--color-surface-alt);
  background-image:
    repeating-linear-gradient(90deg, var(--hair) 0 1px, transparent 1px 88px),
    repeating-linear-gradient(0deg, var(--hair) 0 1px, transparent 1px 88px),
    linear-gradient(160deg, var(--color-primary-soft) 0%, color-mix(in srgb, var(--color-highlight) 40%, var(--color-surface)) 100%);
}

.media-block__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-block__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}

.media-block__body {
  position: relative;
  z-index: 2;
  padding: var(--space-4);
  color: var(--color-contrast-ink);
}

.media-block__body h2,
.media-block__body h3 { color: var(--color-contrast-ink); }

.media-block--16x9 { aspect-ratio: 16 / 9; }
.media-block--21x9 { aspect-ratio: 21 / 9; }
.media-block--1x1 { aspect-ratio: 1 / 1; }

/* ================= 面包屑 & 正文容器 ================= */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

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

.breadcrumb li + li::before {
  content: "/";
  margin-inline-end: var(--space-1);
  color: var(--color-line);
}

.breadcrumb a {
  color: var(--color-ink-soft);
  text-decoration: none;
}

.breadcrumb a:hover { color: var(--color-accent); }

.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.prose > * + * { margin-top: var(--space-3); }

.prose h2 { margin-top: var(--space-6); font-size: var(--text-2xl); }
.prose h3 { margin-top: var(--space-4); font-size: var(--text-xl); }

.prose ul,
.prose ol { padding-inline-start: 1.35em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 6px; }

.prose a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

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

.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  padding: 2px 6px;
  border-radius: 6px;
  background: var(--color-surface-deep);
}

/* ================= 顶部玻璃细条 ================= */
.site-header { position: relative; z-index: 40; }

.skip-link {
  position: fixed;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 100;
  padding: 10px 18px;
  border-radius: var(--radius-pill);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform 160ms var(--ease-out);
}

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

.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--topbar-h);
  z-index: 40;
  background: color-mix(in srgb, var(--color-surface) 78%, transparent);
  border-bottom: var(--border-thin) solid var(--color-line);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
  backdrop-filter: blur(16px) saturate(1.2);
}

.topbar__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding-inline: var(--space-2);
  max-width: var(--container);
  margin-inline: auto;
}

.topbar__progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transform-origin: left center;
  will-change: transform;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--color-heading);
  flex: 0 0 auto;
}

.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 26px;
  border-radius: var(--radius-pill);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
}

.brand__text { display: flex; flex-direction: column; line-height: 1.1; }

.brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

/* 索引带 */
.indexstrip {
  display: none;
  align-items: center;
  gap: 2px;
  margin-inline: auto;
}

.indexstrip__link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 10px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid transparent;
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}

.indexstrip__link:hover {
  background: color-mix(in srgb, var(--color-primary-soft) 72%, transparent);
  border-color: var(--color-line);
  color: var(--color-heading);
}

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

/* 口径微数字 */
.topbar__meta {
  display: none;
  align-items: center;
  gap: var(--space-1);
  margin-inline-start: auto;
}

.meta-chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid var(--color-line);
  background: var(--glass);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* 抽屉按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  margin-inline-start: auto;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid var(--color-line);
  background: var(--glass);
  color: var(--color-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  cursor: pointer;
}

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

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 16px;
  height: 14px;
}

.nav-toggle__bars > span {
  display: block;
  height: 1px;
  background: currentColor;
}

/* ================= 侧边轨道导航 / 移动抽屉 ================= */
.site-nav {
  position: fixed;
  top: var(--topbar-h);
  left: 0;
  bottom: 0;
  width: min(84vw, 320px);
  z-index: 35;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-2);
  overflow-y: auto;
  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
  border-right: var(--border-thin) solid var(--color-line);
  box-shadow: var(--shadow-2);
  -webkit-backdrop-filter: blur(18px) saturate(1.15);
  backdrop-filter: blur(18px) saturate(1.15);
  transform: translateX(-104%);
  transition: transform 240ms var(--ease-out);
}

.site-nav[data-open="true"] { transform: translateX(0); }

.site-nav__title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  padding-inline: 12px;
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.site-nav__link {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: var(--border-thin) solid transparent;
  color: var(--color-ink);
  text-decoration: none;
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}

.site-nav__link:hover {
  background: color-mix(in srgb, var(--color-surface) 76%, transparent);
  border-color: var(--color-line);
  color: var(--color-heading);
}

.site-nav__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 22px;
  border-radius: var(--radius-pill);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
}

.site-nav__label { white-space: nowrap; }

.site-nav__link[aria-current="page"] {
  background: var(--color-highlight);
  border-color: color-mix(in srgb, var(--color-accent) 34%, transparent);
  color: var(--color-accent);
  font-weight: var(--weight-heading);
}

.site-nav__link[aria-current="page"] .site-nav__num {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

/* 竖向滚动刻度 */
.nav-rail { display: none; }

.nav-rail__track {
  position: relative;
  display: block;
  width: 2px;
  height: 104px;
  border-radius: var(--radius-pill);
  background: color-mix(in srgb, var(--color-ink-muted) 28%, transparent);
  overflow: hidden;
}

.nav-rail__fill {
  position: absolute;
  inset: 0;
  display: block;
  background: linear-gradient(180deg, var(--color-accent), var(--color-primary));
  transform: scaleY(0);
  transform-origin: bottom center;
  will-change: transform;
}

.nav-rail__pct {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  font-variant-numeric: tabular-nums;
}

/* 移动端抽屉遮罩 */
body[data-nav-open="true"]::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--color-contrast-surface) 55%, transparent);
}

/* ================= 页脚深条 ================= */
.site-footer {
  margin-top: var(--section-y-lg);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.site-footer__inner {
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-2) var(--space-3) var(--space-3);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
}

.site-footer__brand {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1);
  margin-inline-end: auto;
}

.site-footer__mark {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
}

.site-footer__meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
  font-variant-numeric: tabular-nums;
}

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

.site-footer__links li + li::before {
  content: "·";
  margin-inline-end: var(--space-1);
  color: var(--color-contrast-line);
}

.site-footer__links a {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
  text-decoration: none;
  border-bottom: var(--border-thin) solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}

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

.site-footer__mail {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-accent);
  word-break: break-all;
}

/* ================= 显现 / 返回顶部 ================= */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 240ms var(--ease-out), transform 240ms var(--ease-out);
}

html.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

.to-top {
  position: fixed;
  right: var(--space-2);
  bottom: var(--space-2);
  z-index: 25;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: var(--radius-pill);
  border: var(--border-thin) solid var(--color-line);
  background: var(--glass-strong);
  color: var(--color-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  cursor: pointer;
  box-shadow: var(--shadow-1);
  -webkit-backdrop-filter: blur(14px) saturate(1.2);
  backdrop-filter: blur(14px) saturate(1.2);
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: opacity 200ms var(--ease-out), transform 200ms var(--ease-out);
}

.to-top.is-visible {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.to-top__arrow { font-family: var(--font-mono); color: var(--color-accent); }

/* ================= 焦点 ================= */
:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ================= 响应式 ================= */
@media (min-width: 600px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .topbar__meta { display: inline-flex; }
}

@media (min-width: 768px) {
  .container { padding-inline: var(--space-4); }
  .topbar__inner { padding-inline: var(--space-4); }
  .site-footer__inner { padding: var(--space-2) var(--space-4) var(--space-3); }
  .tabs__bar { gap: var(--space-2); }
}

@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }

  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .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-12 { grid-column: span 12; }

  .indexstrip { display: inline-flex; }
  .nav-toggle { display: none; }

  .site-nav {
    width: var(--rail-w);
    transform: none;
    box-shadow: none;
    padding: var(--space-4) var(--space-2);
    justify-content: space-between;
    background: color-mix(in srgb, var(--color-primary-soft) 46%, transparent);
    border-right: var(--border-thin) solid var(--color-line);
    -webkit-backdrop-filter: blur(12px) saturate(1.1);
    backdrop-filter: blur(12px) saturate(1.1);
    z-index: 30;
  }

  .site-nav[data-open="true"] { transform: none; }

  .nav-rail {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    padding-inline: 12px;
  }

  body[data-nav-open="true"]::after { content: none; }

  .to-top { right: var(--space-4); bottom: var(--space-4); }
}

@media (min-width: 1240px) {
  .layer { padding: var(--space-6); }
}

/* 无 backdrop-filter 时的回退：提高玻璃不透明度 */
@supports not ((backdrop-filter: blur(2px)) or (-webkit-backdrop-filter: blur(2px))) {
  .panel,
  .tabs__btn,
  .to-top { background: var(--color-surface); }
  .topbar { background: var(--color-surface); }
  .site-nav { background: var(--color-surface); }
}

/* ================= 动效降级 ================= */
@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;
  }

  html.js [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .btn:hover { transform: none; }
  .site-nav { transition: none; }
}