:root {
  --color-surface: #fafafa;
  --color-surface-alt: #f1f1f1;
  --color-surface-deep: #e5e5e4;
  --color-ink: #4f4745;
  --color-ink-soft: #776d69;
  --color-ink-muted: #867c79;
  --color-line: #dbdad9;
  --color-primary: #b75c3e;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #f1e4e0;
  --color-accent: #e11e6d;
  --color-accent-ink: #ffffff;
  --color-highlight: #f6d2e1;
  --color-focus: #db1062;
  --color-contrast-surface: #1a1311;
  --color-contrast-ink: #e7e5e4;
  --color-contrast-line: #47413f;
  --color-contrast-accent: #e4397f;
  --overlay-scrim: linear-gradient(180deg, rgba(26, 19, 17, 0.35) 0%, rgba(26, 19, 17, 0.72) 55%, rgba(26, 19, 17, 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: 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(34px, 6.2vw, 79px);
  --text-figure: clamp(28px, 4.5vw, 57px);
  --weight-heading: 667;
  --weight-body: 400;
  --leading-body: 1.78;
  --leading-heading: 1.18;
  --tracking-heading: -0.003em;
  --radius-sm: 14px;
  --radius-md: 20px;
  --radius-lg: 25px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 6px 18px rgba(79, 71, 69, 0.08);
  --shadow-2: 0 18px 44px rgba(79, 71, 69, 0.14);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1260px;
  --measure: 72ch;
  --gutter: 24px;
  --section-y: 98px;
  --section-y-lg: 137px;
}

/* ============ 1. 重置与中文排版 ============ */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  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);
  font-variant-numeric: tabular-nums;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  text-wrap: balance;
}
img, svg, video { display: block; max-width: 100%; }
ul, ol { list-style: none; padding: 0; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
p { text-wrap: pretty; }
:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }

/* ============ 2. 布局骨架 ============ */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-block: var(--section-y); }
.section--tight { padding-block: var(--space-8); }
.section--lg { padding-block: var(--section-y-lg); }
.section--alt { background-color: var(--color-surface-alt); }
.section--deep { background-color: var(--color-surface-deep); }
.section--veil {
  background-color: var(--color-surface);
  background-image: linear-gradient(135deg,
    var(--color-primary-soft) 0%,
    var(--color-surface) 46%,
    var(--color-highlight) 100%);
}
.section--data {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--data .section__head { border-bottom-color: var(--color-contrast-line); }
.section--data .section__title,
.section--data h2,
.section--data h3 { color: var(--color-contrast-ink); }
.section--data .section__lead,
.section--data .entry__text,
.section--data .muted { color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent); }
.section--data .entry-list,
.section--data .entry { border-color: var(--color-contrast-line); }
.section--data .entry:hover { background-color: color-mix(in srgb, var(--color-contrast-ink) 8%, transparent); }
.section--data .entry__title { color: var(--color-contrast-ink); }
.section--data .entry__num { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); border-top-color: var(--color-contrast-accent); }
.section--data .rule { background-color: var(--color-contrast-line); }

.grid { display: grid; gap: var(--gutter); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.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; }

.stack > * + * { margin-top: var(--space-3); }
.stack--tight > * + * { margin-top: var(--space-2); }
.measure { max-width: var(--measure); }
.rule { height: var(--border-thin); background-color: var(--color-line); border: 0; }
.rule--accent { background-color: var(--color-accent); }
.muted { color: var(--color-ink-muted); }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ============ 3. 标题体系 ============ */
.display-title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.figure {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
  display: inline-block;
}
.figure--accent { color: var(--color-accent); }
.figure--on-dark { color: var(--color-contrast-ink); }
.eyebrow {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-primary);
}
.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.section__title { font-size: var(--text-3xl); color: var(--color-ink); }
.section__lead {
  max-width: 58ch;
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

/* ============ 4. 徽标与状态 ============ */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1.5;
  white-space: nowrap;
}
.chip--group {
  background-color: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 26%, transparent);
  color: color-mix(in srgb, var(--color-primary) 78%, var(--color-ink));
}
.chip--accent {
  background-color: var(--color-highlight);
  border-color: color-mix(in srgb, var(--color-accent) 30%, transparent);
  color: color-mix(in srgb, var(--color-accent) 74%, var(--color-ink));
}
.chip--num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; letter-spacing: 0.02em; }
.chip--version { border-style: dashed; color: var(--color-ink-muted); background-color: transparent; }
.chip--on-dark {
  background-color: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.status-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
  flex: 0 0 auto;
}

/* ============ 5. 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color 180ms cubic-bezier(.2,.7,.3,1),
              color 180ms cubic-bezier(.2,.7,.3,1),
              border-color 180ms cubic-bezier(.2,.7,.3,1);
}
.btn--primary {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover { background-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface)); }
.btn--ghost {
  background-color: transparent;
  border-color: var(--color-line);
  color: var(--color-ink);
}
.btn--ghost:hover { border-color: var(--color-accent); color: var(--color-accent); }
.btn--coord { background-color: var(--color-primary); color: var(--color-primary-ink); }
.btn--coord::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-highlight);
}
.btn--coord:hover { background-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface)); }

/* ============ 6. 条目列表 ============ */
.entry-list { border-top: var(--border-thin) solid var(--color-line); }
.entry {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) auto;
  gap: var(--space-3);
  align-items: start;
  padding: var(--space-3) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
  transition: background-color 180ms cubic-bezier(.2,.7,.3,1),
              transform 180ms cubic-bezier(.2,.7,.3,1);
}
.entry:hover {
  background-color: color-mix(in srgb, var(--color-primary-soft) 42%, transparent);
  transform: translateY(-1px);
}
.entry__num {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  padding-top: 6px;
  border-top: var(--border-thin) solid var(--color-primary);
}
.entry__body { min-width: 0; }
.entry__title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
  margin-bottom: 6px;
}
.entry__text {
  max-width: var(--measure);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.entry__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: flex-end;
}

/* ============ 7. 深色数据面板 ============ */
.board {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-2);
}
.board__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}
.board__title { font-size: var(--text-lg); color: var(--color-contrast-ink); }
.board__figure {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-contrast-ink);
}
.board__unit {
  margin-left: 6px;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}
.board__grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
.board__cell {
  padding: var(--space-2) var(--space-2) var(--space-2) 0;
  border-top: var(--border-thin) solid var(--color-contrast-line);
}
.board__caption {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 64%, transparent);
}
.board__legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
}
.bar {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  height: calc(var(--space-8) * 1.5);
}
.bar__col {
  position: relative;
  flex: 1 1 0;
  height: var(--bar-h, 42%);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  background-color: color-mix(in srgb, var(--color-contrast-ink) 24%, transparent);
  transition: background-color 180ms cubic-bezier(.2,.7,.3,1);
}
.bar__col:hover,
.bar__col:focus-visible { background-color: color-mix(in srgb, var(--color-contrast-ink) 42%, transparent); }
.bar__col[data-current="true"] { background-color: var(--color-contrast-accent); }
.bar__col::after {
  content: attr(data-value);
  position: absolute;
  left: 50%;
  bottom: calc(100% + 6px);
  transform: translateX(-50%);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background-color: var(--color-contrast-ink);
  color: var(--color-contrast-surface);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms cubic-bezier(.2,.7,.3,1);
}
.bar__col:hover::after,
.bar__col:focus-visible::after { opacity: 1; }

/* ============ 8. 图片容器（去边直角 + 网格 + 遮罩） ============ */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: 0;
  background-color: var(--color-surface-deep);
  isolation: isolate;
}
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--3x2 { aspect-ratio: 3 / 2; }
.media__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.72) contrast(1.04) brightness(0.96);
}
.media__grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image:
    linear-gradient(to right, color-mix(in srgb, var(--color-contrast-ink) 26%, transparent) 0 var(--border-thin), transparent var(--border-thin) 100%),
    linear-gradient(to bottom, color-mix(in srgb, var(--color-contrast-ink) 26%, transparent) 0 var(--border-thin), transparent var(--border-thin) 100%);
  background-size: 40px 40px;
}
.media__scrim { position: absolute; inset: 0; background-image: var(--overlay-scrim); pointer-events: none; }
.media__caption {
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 2;
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.6;
}
.media__marker {
  position: absolute;
  top: var(--space-2);
  left: var(--space-2);
  width: 14px;
  height: 14px;
  border-top: var(--border-thin) solid var(--color-contrast-ink);
  border-left: var(--border-thin) solid var(--color-contrast-ink);
  opacity: 0.7;
  z-index: 2;
  pointer-events: none;
}

/* ============ 9. 面包屑 / 表格 / 面板 / 正文 ============ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.breadcrumb__item { display: inline-flex; align-items: center; }
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: color-mix(in srgb, var(--color-ink-muted) 58%, transparent);
}
.breadcrumb a { color: var(--color-ink-soft); }
.breadcrumb a:hover { color: var(--color-accent); }

.table { width: 100%; border-collapse: collapse; font-size: var(--text-sm); }
.table th, .table td {
  padding: var(--space-2);
  text-align: left;
  border-bottom: var(--border-thin) solid var(--color-line);
  vertical-align: top;
}
.table thead th {
  background-color: var(--color-surface-deep);
  color: var(--color-ink-soft);
  font-weight: 500;
  letter-spacing: 0.06em;
}
.table td.num, .table th.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.panel {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  background-image: linear-gradient(160deg,
    var(--color-surface) 0%,
    color-mix(in srgb, var(--color-primary-soft) 58%, var(--color-surface)) 100%);
  box-shadow: var(--shadow-1);
}
.panel__title {
  font-size: var(--text-lg);
  color: var(--color-ink);
}
.panel__brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}
.panel__mark {
  padding: 3px 8px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 38%, transparent);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-primary);
}
.panel__text { font-size: var(--text-sm); color: var(--color-ink-soft); }
.panel__meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
  word-break: break-all;
}
.panel__list { display: flex; flex-direction: column; gap: var(--space-1); }
.panel__list li {
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  padding-bottom: var(--space-1);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.panel__list li:last-child { border-bottom: 0; padding-bottom: 0; }
.panel__list a { color: var(--color-ink); border-bottom: var(--border-thin) solid transparent; }
.panel__list a:hover { color: var(--color-accent); border-bottom-color: var(--color-accent); }
.panel__defs { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 6px var(--space-2); }
.panel__term { font-size: var(--text-xs); color: var(--color-ink-muted); letter-spacing: 0.06em; }
.panel__desc { font-size: var(--text-sm); color: var(--color-ink); }

.prose { max-width: var(--measure); font-size: var(--text-base); color: var(--color-ink); }
.prose h2 { font-size: var(--text-2xl); margin: var(--space-6) 0 var(--space-2); }
.prose h3 { font-size: var(--text-xl); margin: var(--space-4) 0 var(--space-2); }
.prose p { margin-bottom: var(--space-2); }
.prose ul { list-style: none; margin-bottom: var(--space-2); }
.prose li {
  position: relative;
  padding-left: var(--space-3);
  margin-bottom: 6px;
}
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 10px;
  height: var(--border-thin);
  background-color: var(--color-primary);
}
.prose a { color: var(--color-primary); text-decoration: underline; text-underline-offset: 3px; }
.prose a:hover { color: var(--color-accent); }

/* ============ 10. 头部 ============ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -64px;
  z-index: 200;
  padding: 10px var(--space-2);
  border-radius: var(--radius-sm);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  transition: top 180ms cubic-bezier(.2,.7,.3,1);
}
.skip-link:focus { top: var(--space-2); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background-color: transparent;
  border-bottom: var(--border-thin) solid transparent;
  transition: background-color 200ms cubic-bezier(.2,.7,.3,1),
              border-color 200ms cubic-bezier(.2,.7,.3,1),
              box-shadow 200ms cubic-bezier(.2,.7,.3,1);
}
.site-header[data-solid="true"] {
  background-color: color-mix(in srgb, var(--color-surface) 90%, transparent);
  backdrop-filter: blur(12px) saturate(1.15);
  border-bottom-color: var(--color-line);
  box-shadow: var(--shadow-1);
}
.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  width: 100%;
  max-width: var(--container);
  min-height: 68px;
  margin-inline: auto;
  padding: var(--space-2) var(--gutter);
}
.site-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
}
.site-header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: var(--border-thin);
  background-color: transparent;
}
.site-header__progress-fill {
  display: block;
  width: 0;
  height: 100%;
  background-color: var(--color-accent);
  transition: width 120ms linear;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  min-width: 0;
  color: var(--color-ink);
}
.brand__mark {
  padding: 4px 8px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 40%, transparent);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: var(--text-xs);
  font-weight: var(--weight-heading);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-primary);
}
.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.brand__rule { width: var(--border-thin); height: 20px; background-color: var(--color-line); }
.brand__sub {
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.nav { flex: 1 1 auto; min-width: 0; display: flex; align-items: center; }
.nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  overflow-x: auto;
  scrollbar-width: none;
}
.nav__list::-webkit-scrollbar { display: none; }
.nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-ink-soft);
  white-space: nowrap;
  transition: color 180ms cubic-bezier(.2,.7,.3,1),
              background-color 180ms cubic-bezier(.2,.7,.3,1);
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 2px;
  height: var(--border-thin);
  background-color: transparent;
  transition: background-color 180ms cubic-bezier(.2,.7,.3,1);
}
.nav__link:hover { color: var(--color-ink); background-color: color-mix(in srgb, var(--color-primary-soft) 55%, transparent); }
.nav__link:hover::after { background-color: var(--color-accent); }
.nav__link[aria-current="page"] {
  color: var(--color-ink);
  background-color: color-mix(in srgb, var(--color-primary-soft) 70%, transparent);
}
.nav__link[aria-current="page"]::after { background-color: var(--color-accent); }
.nav__drawer { display: none; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-ink);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: border-color 180ms cubic-bezier(.2,.7,.3,1), color 180ms cubic-bezier(.2,.7,.3,1);
}
.nav-toggle:hover { border-color: var(--color-accent); color: var(--color-accent); }
.nav-toggle__bars { display: flex; flex-direction: column; gap: 4px; width: 16px; }
.nav-toggle__bars span {
  display: block;
  height: var(--border-thin);
  background-color: currentColor;
  transition: transform 180ms cubic-bezier(.2,.7,.3,1);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child { transform: translateY(2.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child { transform: translateY(-2.5px) rotate(-45deg); }
.nav-toggle__label { letter-spacing: 0.08em; }

.nav-group { border-bottom: var(--border-thin) solid var(--color-line); }
.nav-group__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: var(--space-2);
  padding: var(--space-2) 0;
  border: 0;
  background: none;
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.14em;
  color: var(--color-ink);
  text-align: left;
  cursor: pointer;
}
.nav-group__toggle::after {
  content: "";
  width: 8px;
  height: 8px;
  border-right: var(--border-thin) solid var(--color-ink-muted);
  border-bottom: var(--border-thin) solid var(--color-ink-muted);
  transform: rotate(45deg);
  transition: transform 180ms cubic-bezier(.2,.7,.3,1);
}
.nav-group__toggle[aria-expanded="true"]::after { transform: rotate(-135deg); }
.nav-group__panel { padding-bottom: var(--space-2); }
.nav-group__list { display: flex; flex-direction: column; }
.nav-group__list a {
  display: block;
  padding: 10px 0 10px var(--space-2);
  border-left: var(--border-thin) solid var(--color-line);
  font-size: var(--text-base);
  color: var(--color-ink-soft);
  transition: color 180ms cubic-bezier(.2,.7,.3,1),
              border-color 180ms cubic-bezier(.2,.7,.3,1),
              padding-left 180ms cubic-bezier(.2,.7,.3,1);
}
.nav-group__list a:hover,
.nav-group__list a[aria-current="page"] {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  padding-left: calc(var(--space-2) + 4px);
}

/* ============ 11. 页脚 ============ */
.site-footer {
  padding-block: var(--space-8) var(--space-6);
  border-top: var(--border-thin) solid var(--color-line);
  background-color: var(--color-surface);
  background-image: linear-gradient(150deg,
    var(--color-surface) 0%,
    color-mix(in srgb, var(--color-primary-soft) 68%, var(--color-surface)) 58%,
    color-mix(in srgb, var(--color-highlight) 68%, var(--color-surface)) 100%);
}
.footer-panels {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--gutter);
}
.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-4);
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.footer-base__note { letter-spacing: 0.04em; }

.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 140;
  padding: 10px 14px;
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  cursor: pointer;
  box-shadow: var(--shadow-1);
  transition: border-color 180ms cubic-bezier(.2,.7,.3,1), color 180ms cubic-bezier(.2,.7,.3,1);
}
.to-top:hover { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); }

/* ============ 12. 显现动效 ============ */
[data-reveal] {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 240ms cubic-bezier(.2,.7,.3,1), transform 240ms cubic-bezier(.2,.7,.3,1);
}
[data-reveal].is-visible { opacity: 1; transform: none; }

/* ============ 13. 响应式 ============ */
@media (max-width: 1100px) {
  .footer-panels { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 980px) {
  :root { --section-y: 72px; --section-y-lg: 96px; }
  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5 { grid-column: span 3; }
  .col-6 { grid-column: span 6; }
  .col-7, .col-8, .col-9, .col-12 { grid-column: span 6; }
  .brand__rule, .brand__sub { display: none; }
  .chip--version { display: none; }
  .nav-toggle { display: inline-flex; }
  .nav {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 110;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-3) var(--gutter) var(--space-6);
    overflow-y: auto;
    background-color: var(--color-surface);
    background-image: linear-gradient(180deg,
      var(--color-surface) 0%,
      color-mix(in srgb, var(--color-primary-soft) 42%, var(--color-surface)) 100%);
    border-top: var(--border-thin) solid var(--color-line);
  }
  .nav[data-open="true"] { display: flex; }
  .nav__list { display: none; }
  .nav__drawer { display: block; width: 100%; }
  .entry { grid-template-columns: 52px minmax(0, 1fr); }
  .entry__tags { grid-column: 2 / 3; justify-content: flex-start; }
}
@media (max-width: 640px) {
  :root { --section-y: 56px; --section-y-lg: 72px; }
  .grid--12 { grid-template-columns: minmax(0, 1fr); }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-12 { grid-column: 1 / -1; }
  .footer-panels { grid-template-columns: minmax(0, 1fr); }
  .site-header__inner { gap: var(--space-2); }
  .brand__name { font-size: var(--text-base); }
  .btn--coord { padding: 9px 12px; }
  .entry { grid-template-columns: minmax(0, 1fr); gap: var(--space-2); }
  .entry__tags { grid-column: 1 / -1; }
  .board { padding: var(--space-3); border-radius: var(--radius-md); }
  .to-top { right: var(--space-2); bottom: var(--space-2); }
}

/* ============ 14. 无障碍与减弱动效 ============ */
@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;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .entry:hover { transform: none; }
}