:root {
  --color-surface: #f7f8f8;
  --color-surface-alt: #eeeff0;
  --color-surface-deep: #e1e3e4;
  --color-ink: #40484e;
  --color-ink-soft: #646e77;
  --color-ink-muted: #75808a;
  --color-line: #d6d8d9;
  --color-primary: #4178aa;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dee6ed;
  --color-accent: #168188;
  --color-accent-ink: #ffffff;
  --color-highlight: #cee3e4;
  --color-focus: #0d7b82;
  --color-contrast-surface: #192026;
  --color-contrast-ink: #e4e6e7;
  --color-contrast-line: #464c50;
  --color-contrast-accent: #24d1db;
  --overlay-scrim: linear-gradient(180deg, rgba(25, 32, 38, 0.35) 0%, rgba(25, 32, 38, 0.72) 55%, rgba(25, 32, 38, 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: 9.7px;
  --text-sm: 13.0px;
  --text-base: 15px;
  --text-lg: 20.0px;
  --text-xl: 26.7px;
  --text-2xl: 35.5px;
  --text-3xl: 47.4px;
  --text-4xl: 63.1px;
  --text-display: clamp(35px, 7.2vw, 92px);
  --text-figure: clamp(29px, 5.2vw, 66px);
  --weight-heading: 719;
  --weight-body: 400;
  --leading-body: 1.73;
  --leading-heading: 1.24;
  --tracking-heading: 0.03em;
  --radius-sm: 1px;
  --radius-md: 1px;
  --radius-lg: 1px;
  --radius-pill: 1px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 7px;
  --space-2: 14px;
  --space-3: 21px;
  --space-4: 28px;
  --space-6: 42px;
  --space-8: 56px;
  --container: 1360px;
  --measure: 71ch;
  --gutter: 21px;
  --section-y: 87px;
  --section-y-lg: 122px;
}

/* ============================================================
   01 · RESET
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
}
body { margin: 0; }
h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }
ul, ol { padding: 0; }
ul[class], ol[class] { list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; margin: 0; }

/* ============================================================
   02 · 中文排版与页面基底（工程蓝图点线网格）
   ============================================================ */
body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  color: var(--color-ink);
  background-color: var(--color-surface);
  background-image: radial-gradient(
    color-mix(in srgb, var(--color-line) 92%, transparent) 1px,
    transparent 1.4px
  );
  background-size: 21px 21px;
  background-position: 0 0;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
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-ink);
}
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 { max-width: var(--measure); }
strong { font-weight: 700; }
:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}
::selection { background: var(--color-highlight); color: var(--color-ink); }

.mono,
.eyebrow,
.crumbs__list,
.brand__sub,
.site-header__status,
.footer__head,
.footer__icp,
.footer__copy,
.rail__item,
.tag,
.tabs__tab,
.step__no,
.stat__label,
.figure__cap,
.figure__coord { font-family: var(--font-mono); }

.mono { font-size: var(--text-sm); letter-spacing: 0.06em; }
.eyebrow {
  display: inline-block;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-primary);
}
.display-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 1.02;
  letter-spacing: 0.02em;
  color: var(--color-ink);
}

/* ============================================================
   03 · 布局：容器 / 分节 / 网格
   ============================================================ */
.wrap {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.wrap--narrow { max-width: 960px; }

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--alt { background: var(--color-surface-alt); }
.section--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--deep h4 { color: var(--color-contrast-ink); }
.section--deep p { color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent); }
.section--deep .eyebrow,
.section--deep .mono { color: var(--color-contrast-accent); }

.grid { display: grid; gap: var(--space-3); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--6 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.col-2 { grid-column: span 2; }
.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-10 { grid-column: span 10; }
.col-12 { grid-column: span 12; }

@media (min-width: 1025px) {
  .offset-up { margin-top: calc(var(--space-6) * -1); }
}

/* ============================================================
   04 · 分节头 / 分隔语言 / 链接 / 按钮
   ============================================================ */
.sec-head {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(0, 1fr);
  gap: var(--space-1) var(--space-4);
  align-items: baseline;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-6);
  border-bottom: var(--border-thick) solid var(--color-ink);
}
.sec-head__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-primary);
}
.sec-head__title { font-size: var(--text-2xl); }
.sec-head__meta {
  grid-column: 2;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.section--deep .sec-head { border-bottom-color: var(--color-contrast-ink); }
.section--deep .sec-head__no { color: var(--color-contrast-accent); }
.section--deep .sec-head__meta { color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent); }

.rule { border-top: var(--border-thin) dotted var(--color-line); }
.rule--double { border-top: 3px double var(--color-ink); }
.rule--thick { border-top: var(--border-thick) solid var(--color-ink); }
.section--deep .rule,
.section--deep .rule--double,
.section--deep .rule--thick { border-color: var(--color-contrast-line); }

.link {
  color: var(--color-primary);
  border-bottom: var(--border-thin) dotted var(--color-primary);
  transition: color 0.15s linear, border-color 0.15s linear;
}
.link:hover { color: var(--color-accent); border-bottom: var(--border-thin) solid var(--color-accent); }
.link--quiet { color: var(--color-ink-soft); border-bottom-color: var(--color-line); }
.link--quiet:hover { color: var(--color-accent); border-bottom-color: var(--color-accent); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  min-height: 42px;
  padding: 9px var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.06em;
  transition: background-color 0.15s linear, color 0.15s linear, border-color 0.15s linear;
}
.btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-soft);
}
.btn--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover {
  background: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface));
  border-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface));
  color: var(--color-primary-ink);
}
.btn--accent {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.btn--accent:hover {
  background: color-mix(in srgb, var(--color-accent) 82%, var(--color-contrast-surface));
  border-color: color-mix(in srgb, var(--color-accent) 82%, var(--color-contrast-surface));
  color: var(--color-accent-ink);
}
.btn--ghost { background: transparent; }
.btn--block { width: 100%; }

/* ============================================================
   05 · 面包屑 / 面板 / 标签 / 旁注 / 指标
   ============================================================ */
.crumbs { padding-block: var(--space-2); border-bottom: var(--border-thin) dotted var(--color-line); }
.crumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.crumbs__list li { display: inline-flex; align-items: center; gap: var(--space-1); }
.crumbs__list li:not(:first-child)::before { content: "/"; color: var(--color-line); }
.crumbs__list a:hover { color: var(--color-primary); }

.panel {
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
}
.panel--alt { background: var(--color-surface-alt); }
.panel--raised { background: var(--color-surface); border-top: var(--border-thick) solid var(--color-primary); }
.panel--deep {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.panel--deep h3,
.panel--deep h4 { color: var(--color-contrast-ink); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 2px var(--space-1);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface-alt);
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}
.tag--primary {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
  color: var(--color-primary);
}
.tag--accent {
  border-color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 10%, var(--color-surface));
  color: var(--color-accent);
}
.tag--live { border-color: var(--color-accent); color: var(--color-accent); }
.section--deep .tag {
  background: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.section--deep .tag--accent,
.section--deep .tag--live {
  border-color: color-mix(in srgb, var(--color-contrast-accent) 60%, transparent);
  color: var(--color-contrast-accent);
}

.pulse-dot {
  position: relative;
  display: inline-block;
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-contrast-accent);
}
.pulse-dot::after {
  content: "";
  position: absolute;
  inset: -4px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-accent) 52%, transparent);
  border-radius: 50%;
}
.pulse-dot--accent { background: var(--color-accent); }
.pulse-dot--accent::after { border-color: color-mix(in srgb, var(--color-accent) 46%, transparent); }

.note {
  padding: var(--space-2) var(--space-3);
  border-left: var(--border-thick) solid var(--color-accent);
  background: var(--color-surface-alt);
  color: var(--color-ink-soft);
  font-size: var(--text-sm);
}
.section--deep .note {
  background: color-mix(in srgb, var(--color-contrast-ink) 8%, transparent);
  color: color-mix(in srgb, var(--color-contrast-ink) 86%, transparent);
}

.stat { display: grid; gap: var(--space-1); }
.stat__value {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1;
  color: var(--color-primary);
}
.stat__label {
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}
.section--deep .stat__value { color: var(--color-contrast-accent); }
.section--deep .stat__label { color: color-mix(in srgb, var(--color-contrast-ink) 66%, transparent); }

/* ============================================================
   06 · 数据表（排名与积分）
   ============================================================ */
.data-table { font-variant-numeric: tabular-nums; }
.data-table caption {
  caption-side: top;
  text-align: left;
  padding-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.data-table th {
  padding: 10px var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--color-ink-soft);
  text-align: left;
  white-space: nowrap;
}
.data-table td {
  padding: 11px var(--space-2);
  border-bottom: var(--border-thin) dotted var(--color-line);
  vertical-align: baseline;
}
.data-table tbody tr:nth-child(even) { background: var(--color-surface-deep); }
.data-table tbody tr:hover { background: var(--color-highlight); }
.data-table .num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
.data-table .num--rank { color: var(--color-primary); }
.data-table .team { font-weight: 600; letter-spacing: 0.02em; }
.data-table__pos { font-family: var(--font-mono); color: var(--color-accent); }
.section--deep .data-table th {
  color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
  border-bottom-color: var(--color-contrast-line);
}
.section--deep .data-table td { border-bottom-color: var(--color-contrast-line); }
.section--deep .data-table tbody tr:nth-child(even) {
  background: color-mix(in srgb, var(--color-contrast-ink) 6%, transparent);
}
.section--deep .data-table tbody tr:hover {
  background: color-mix(in srgb, var(--color-contrast-accent) 14%, transparent);
}
.section--deep .data-table .num--rank { color: var(--color-contrast-accent); }

/* ============================================================
   07 · 图形容器（图片阶段使用）
   ============================================================ */
.figure { display: block; }
.figure__frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface-deep);
}
.figure__frame--wide { aspect-ratio: 21 / 9; }
.figure__frame--tall { aspect-ratio: 4 / 5; }
.figure__frame--square { aspect-ratio: 1 / 1; }
.figure__frame img { width: 100%; height: 100%; object-fit: cover; }
.figure__grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, color-mix(in srgb, var(--color-contrast-ink) 14%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--color-contrast-ink) 14%, transparent) 1px, transparent 1px);
  background-size: 42px 42px;
}
.figure__scrim { position: absolute; inset: 0; background: var(--overlay-scrim); }
.figure__coord {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  padding: 5px var(--space-1);
  background: color-mix(in srgb, var(--color-contrast-surface) 80%, transparent);
  color: var(--color-contrast-accent);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}
.figure__body {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 2;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
}
.figure__body h3,
.figure__body h4 { color: var(--color-contrast-ink); }
.figure__cap {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

/* ============================================================
   08 · 步骤路径与轮次轨道
   ============================================================ */
.steps {
  padding-left: var(--space-4);
  border-left: var(--border-thin) dotted var(--color-line);
}
.step { position: relative; padding: var(--space-3) 0 var(--space-4); }
.step::before {
  content: "";
  position: absolute;
  left: calc(var(--space-4) * -1 - 4px);
  top: calc(var(--space-3) + 8px);
  width: 7px;
  height: 7px;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-primary);
}
.step:last-child { padding-bottom: 0; }
.step__no {
  display: block;
  margin-bottom: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-accent);
}
.step h3, .step h4 { margin-bottom: var(--space-1); }
.section--deep .steps { border-left-color: var(--color-contrast-line); }
.section--deep .step::before { background: var(--color-contrast-surface); border-color: var(--color-contrast-accent); }

.rail {
  display: flex;
  overflow-x: auto;
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
  scrollbar-width: thin;
}
.rail__item {
  flex: 0 0 auto;
  padding: 10px var(--space-2);
  border-right: var(--border-thin) dotted var(--color-line);
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  white-space: nowrap;
  transition: background-color 0.15s linear, color 0.15s linear;
}
.rail__item:hover { color: var(--color-primary); background: var(--color-surface-alt); }
.rail__item--now,
.rail__item[aria-current] {
  color: var(--color-primary);
  background: var(--color-primary-soft);
  border-right-color: var(--color-primary);
}

/* ============================================================
   09 · 标签页与折叠面板
   ============================================================ */
.tabs { display: block; }
.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: var(--border-thick) solid var(--color-ink);
}
.tabs__tab {
  padding: 10px var(--space-3);
  border: var(--border-thin) solid transparent;
  border-bottom: 0;
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  transition: background-color 0.15s linear, color 0.15s linear, border-color 0.15s linear;
}
.tabs__tab:hover { color: var(--color-primary); background: var(--color-surface-alt); }
.tabs__tab[aria-selected="true"] {
  color: var(--color-primary);
  background: var(--color-primary-soft);
  border-color: var(--color-line);
  border-bottom-color: var(--color-surface);
}
.tabs__panel { padding-top: var(--space-4); }
.tabs__panel[hidden] { display: none; }

.fold { border-top: var(--border-thin) dotted var(--color-line); }
.fold:last-child { border-bottom: var(--border-thin) dotted var(--color-line); }
.fold__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2) 0;
  text-align: left;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--color-ink);
  transition: color 0.15s linear;
}
.fold__head::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-accent);
}
.fold__head[aria-expanded="true"]::after { content: "\2212"; }
.fold__head:hover { color: var(--color-primary); }
.fold__body { padding-bottom: var(--space-4); color: var(--color-ink-soft); }
.fold__body[hidden] { display: none; }

/* ============================================================
   10 · 头部（透明叠加 → 实色阅读态）
   ============================================================ */
.skip-link {
  position: fixed;
  top: -120px;
  left: var(--gutter);
  z-index: 200;
  padding: var(--space-1) var(--space-3);
  background: var(--color-accent);
  color: var(--color-accent-ink);
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
}
.skip-link:focus { top: var(--space-2); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: color-mix(in srgb, var(--color-contrast-surface) 82%, transparent);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
  transition: background-color 0.18s linear, color 0.18s linear, border-color 0.18s linear;
}
.site-header[data-scrolled] {
  background: var(--color-surface);
  color: var(--color-ink);
  border-bottom: var(--border-thick) solid var(--color-ink);
}
.site-header__grid {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-2) var(--gutter);
}

.brand { display: flex; align-items: center; gap: var(--space-2); order: 1; }
.brand__mark {
  position: relative;
  flex: none;
  width: 17px;
  height: 17px;
  border: var(--border-thin) solid currentColor;
}
.brand__mark::before {
  content: "";
  position: absolute;
  inset: 3px;
  background: var(--color-accent);
}
.brand__mark::after {
  content: "";
  position: absolute;
  top: 50%;
  left: -4px;
  width: calc(100% + 8px);
  border-top: var(--border-thin) dotted currentColor;
}
.brand__link { display: grid; gap: 1px; }
.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: 0.08em;
}
.brand__sub {
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: color-mix(in srgb, currentColor 66%, transparent);
}

.site-header__status {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  order: 2;
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: color-mix(in srgb, currentColor 76%, transparent);
}

.site-nav { order: 3; margin-left: auto; }
.site-nav__list { display: flex; align-items: center; gap: 2px; }
.site-nav__link {
  display: inline-block;
  padding: 8px 10px;
  border: var(--border-thin) solid transparent;
  border-bottom: var(--border-thin) dotted color-mix(in srgb, currentColor 34%, transparent);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: inherit;
  transition: color 0.15s linear, border-color 0.15s linear, background-color 0.15s linear;
}
.site-nav__link:hover {
  color: var(--color-accent);
  border-bottom: var(--border-thin) solid var(--color-accent);
}
.site-nav__link[aria-current="page"] {
  color: var(--color-accent);
  border-bottom: var(--border-thick) solid var(--color-accent);
}
.site-header[data-scrolled] .site-nav__link:hover,
.site-header[data-scrolled] .site-nav__link[aria-current="page"] { color: var(--color-focus); }
.site-header[data-scrolled] .site-nav__link[aria-current="page"] { border-bottom-color: var(--color-focus); }

.site-header__cta {
  order: 4;
  min-height: 36px;
  padding: 7px var(--space-2);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
}

.nav-toggle {
  display: none;
  order: 5;
  align-items: center;
  gap: var(--space-1);
  padding: 8px var(--space-2);
  border: var(--border-thin) solid color-mix(in srgb, currentColor 38%, transparent);
  border-radius: var(--radius-sm);
  color: inherit;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  transition: color 0.15s linear, border-color 0.15s linear;
}
.nav-toggle:hover { color: var(--color-accent); border-color: var(--color-accent); }
.nav-toggle__bars {
  position: relative;
  display: inline-block;
  width: 16px;
  height: 10px;
  border-top: var(--border-thin) solid currentColor;
  border-bottom: var(--border-thin) solid currentColor;
}
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  border-top: var(--border-thin) solid currentColor;
}
.nav-toggle[aria-expanded="true"] { color: var(--color-accent); border-color: var(--color-accent); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { border-top-color: transparent; border-bottom-color: transparent; }

.progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: transparent;
}
.progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--color-accent);
  transition: width 0.12s linear;
}

@media (max-width: 960px) {
  .nav-toggle { display: inline-flex; }
  .site-header__status { order: 6; flex-basis: 100%; padding-top: var(--space-1); }
  .site-header__cta { order: 3; margin-left: auto; }
  .site-nav {
    order: 5;
    display: none;
    flex-basis: 100%;
    margin-left: 0;
    margin-top: var(--space-1);
    padding-top: var(--space-1);
    border-top: var(--border-thin) solid color-mix(in srgb, currentColor 26%, transparent);
  }
  .site-header[data-open] .site-nav,
  .site-nav[data-open] { display: block; }
  .site-nav__list { flex-direction: column; align-items: stretch; }
  .site-nav__link {
    display: block;
    padding: 11px 2px;
    border-bottom: var(--border-thin) dotted color-mix(in srgb, currentColor 24%, transparent);
  }
  .site-nav__link[aria-current="page"] { border-bottom-width: var(--border-thin); }
}
@media (max-width: 560px) {
  .site-header__status { font-size: var(--text-xs); }
  .brand__sub { display: none; }
}

/* ============================================================
   11 · 阶梯式页脚
   ============================================================ */
.site-footer {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thick) solid var(--color-accent);
}
.footer__tier { padding-block: var(--space-8); }
.footer__tier--index {
  background-image: radial-gradient(
    color-mix(in srgb, var(--color-contrast-line) 70%, transparent) 1px,
    transparent 1.4px
  );
  background-size: 21px 21px;
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}
.footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.3fr);
  gap: var(--space-6);
}
.footer__brand { display: grid; gap: var(--space-1); align-content: start; }
.brand__mark--footer { color: var(--color-contrast-ink); margin-bottom: var(--space-1); }
.footer__brand-name {
  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__brand-sub {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-contrast-accent);
}
.footer__note {
  max-width: 46ch;
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}
.footer__col { display: grid; align-content: start; gap: var(--space-2); }
.footer__head {
  padding-bottom: var(--space-1);
  border-bottom: var(--border-thin) dotted var(--color-contrast-line);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}
.footer__list { display: grid; gap: 0; }
.footer__list a {
  display: block;
  padding: 8px 0;
  border-bottom: var(--border-thin) dotted color-mix(in srgb, var(--color-contrast-line) 80%, transparent);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  transition: color 0.15s linear, border-color 0.15s linear;
}
.footer__list a:hover {
  color: var(--color-contrast-accent);
  border-bottom: var(--border-thin) solid var(--color-contrast-accent);
}
.footer__list--plain li {
  display: flex;
  gap: var(--space-2);
  padding: 8px 0;
  border-bottom: var(--border-thin) dotted color-mix(in srgb, var(--color-contrast-line) 80%, transparent);
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 88%, transparent);
}
.footer__k {
  flex: none;
  min-width: 42px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-contrast-accent);
}
.footer__tier--legal { padding-block: var(--space-4); }
.footer__legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
}
.footer__legal-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}
.footer__legal-list a {
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) dotted var(--color-contrast-line);
  transition: color 0.15s linear, border-color 0.15s linear;
}
.footer__legal-list a:hover {
  color: var(--color-contrast-accent);
  border-bottom: var(--border-thin) solid var(--color-contrast-accent);
}
.footer__icp,
.footer__copy {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 60%, transparent);
}

@media (max-width: 1024px) {
  .footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-4); }
}
@media (max-width: 680px) {
  .footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer__tier { padding-block: var(--space-6); }
  .footer__legal { justify-content: flex-start; }
}

/* ============================================================
   12 · 响应式与动效偏好
   ============================================================ */
@media (max-width: 1024px) {
  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-5, .col-6, .col-7, .col-8, .col-9, .col-10, .col-11, .col-12 { grid-column: span 6; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 680px) {
  .section, .section--lg { padding-block: var(--space-8); }
  .grid--2, .grid--3, .grid--4, .grid--6, .grid--12 { grid-template-columns: minmax(0, 1fr); }
  .col-2, .col-3, .col-4, .col-5, .col-6,
  .col-7, .col-8, .col-9, .col-10, .col-12 { grid-column: 1 / -1; }
  .sec-head { grid-template-columns: minmax(0, 1fr); }
  .sec-head__meta { grid-column: 1; }
  h1 { font-size: var(--text-2xl); }
  h2 { font-size: var(--text-xl); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }
}