:root {
  --color-surface: #fcfcfc;
  --color-surface-alt: #f2f2f2;
  --color-surface-deep: #e3e4e4;
  --color-ink: #2f3337;
  --color-ink-soft: #5a6168;
  --color-ink-muted: #757d85;
  --color-line: #d7d8d9;
  --color-primary: #0875e2;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dae9f8;
  --color-accent: #7d14eb;
  --color-accent-ink: #ffffff;
  --color-highlight: #e5d2f9;
  --color-focus: #7c07f8;
  --color-contrast-surface: #0e1721;
  --color-contrast-ink: #e4e5e7;
  --color-contrast-line: #3d444d;
  --color-contrast-accent: #a45af1;
  --overlay-scrim: linear-gradient(180deg, rgba(14, 23, 33, 0.35) 0%, rgba(14, 23, 33, 0.72) 55%, rgba(14, 23, 33, 0.92) 100%);
  --font-heading: "Source Han Sans SC", "Noto Sans SC", SimHei, "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 9.5px;
  --text-sm: 13.5px;
  --text-base: 16px;
  --text-lg: 22.6px;
  --text-xl: 32.0px;
  --text-2xl: 45.2px;
  --text-3xl: 64.0px;
  --text-4xl: 90.4px;
  --text-display: clamp(60px, 12.4vw, 159px);
  --text-figure: clamp(50px, 8.9vw, 114px);
  --weight-heading: 834;
  --weight-body: 400;
  --leading-body: 1.74;
  --leading-heading: 1.25;
  --tracking-heading: -0.018em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 0px;
  --radius-pill: 0px;
  --border-thin: 2px;
  --border-thick: 2px;
  --shadow-1: 4px 4px 0 #2f3337;
  --shadow-2: 8px 8px 0 #2f3337;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1160px;
  --measure: 73ch;
  --gutter: 24px;
  --section-y: 85px;
  --section-y-lg: 119px;
}

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

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

body {
  margin: 0;
  background: 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;
}

h1, h2, h3, h4, h5, h6 {
  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: inherit;
}

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

ul, ol { margin: 0 0 var(--space-3); padding-left: 1.2em; }

a { color: inherit; text-decoration: none; }

img { display: block; max-width: 100%; height: auto; }

button { font: inherit; color: inherit; }

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

hr { border: 0; height: 0; margin: var(--space-4) 0; }

address { font-style: normal; }

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

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

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

.section-dark {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.section-dark .lede,
.section-dark .prose { color: var(--color-contrast-ink); }

.split {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: var(--gutter);
  align-items: start;
}

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

.grid-9 {
  display: grid;
  grid-template-columns: repeat(9, minmax(0, 1fr));
  gap: var(--gutter);
}

/* ===== 分隔语言 ===== */
.rule-heavy { height: 0; border-top: 4px solid var(--color-ink); }
.rule-double { height: 0; border-top: 6px double var(--color-ink); }

.section-dark .rule-heavy { border-top-color: var(--color-contrast-line); }
.section-dark .rule-double { border-top-color: var(--color-contrast-line); }

/* ===== 排版工具 ===== */
.display {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 0.86;
  letter-spacing: var(--tracking-heading);
  margin: 0;
  overflow-wrap: break-word;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
}

.section-dark .eyebrow { color: var(--color-contrast-accent); }

.lede {
  font-size: var(--text-lg);
  line-height: 1.6;
  max-width: var(--measure);
  color: var(--color-ink-soft);
}

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

.prose p { margin-bottom: var(--space-3); }

.prose h3 {
  font-size: var(--text-lg);
  margin-top: var(--space-4);
  margin-bottom: var(--space-2);
}

.prose ul { padding-left: 1.1em; }
.prose li { margin-bottom: var(--space-1); }

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

/* ===== 编号章节 ===== */
.chapter {
  border-top: 4px solid var(--color-ink);
  padding-top: var(--space-3);
}

.section-dark .chapter { border-top-color: var(--color-contrast-line); }

.chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-4xl);
  line-height: 0.8;
  letter-spacing: -0.06em;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.section-dark .chapter-num { color: var(--color-contrast-accent); }

.chapter-title {
  font-size: var(--text-3xl);
  line-height: 1.02;
  margin: 0 0 var(--space-3);
}

.chapter-body { max-width: var(--measure); }

/* ===== 块面 ===== */
.block {
  position: relative;
  padding: var(--space-4);
  background: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  box-shadow: var(--shadow-2);
}

.block-alt { background: var(--color-surface-alt); }

.block-primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-ink);
  box-shadow: var(--shadow-2);
}

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

.block-dark {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
  box-shadow: var(--shadow-2);
}

.block-hover {
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.block-hover:hover {
  transform: translate(-3px, -3px);
  box-shadow: 12px 12px 0 var(--color-ink);
}

/* ===== 数据组件 ===== */
.stat {
  padding: var(--space-3);
  background: var(--color-surface);
  border: var(--border-thick) solid var(--color-ink);
  box-shadow: var(--shadow-1);
}

.stat-value {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-4xl);
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--color-accent);
  margin-bottom: var(--space-1);
}

.stat-value-lg {
  font-size: var(--text-figure);
  color: var(--color-primary);
}

.stat-label {
  display: block;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  letter-spacing: 0.06em;
}

.section-dark .stat {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
}

.section-dark .stat-value { color: var(--color-contrast-accent); }
.section-dark .stat-label { color: var(--color-contrast-ink); opacity: 0.72; }

.datatable {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  background: var(--color-surface);
}

.datatable th,
.datatable td {
  border: 1px solid var(--color-line);
  padding: 10px var(--space-2);
  text-align: left;
  vertical-align: top;
}

.datatable thead th {
  background: var(--color-surface-deep);
  border-bottom: var(--border-thick) solid var(--color-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  letter-spacing: 0.02em;
}

.datatable tbody tr:nth-child(even) {
  background: color-mix(in srgb, var(--color-surface-deep) 50%, var(--color-surface));
}

.num-cell {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.4;
  background: var(--color-primary-soft);
  border: var(--border-thin) solid var(--color-ink);
  color: var(--color-ink);
}

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

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

/* ===== 按钮与路径 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 14px var(--space-3);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-base);
  line-height: 1;
  background: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  box-shadow: var(--shadow-1);
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-2);
}

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

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

.btn-quiet {
  background: transparent;
  box-shadow: none;
  border-color: currentColor;
}

.btn-quiet:hover {
  transform: none;
  box-shadow: var(--shadow-1);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.breadcrumb a {
  padding: 2px 4px;
  border-bottom: 2px solid transparent;
}

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

.breadcrumb .sep { color: var(--color-ink-muted); }

/* ===== 图片容器 ===== */
.figure {
  margin: 0;
  background: var(--color-surface);
  border: var(--border-thick) solid var(--color-ink);
  box-shadow: var(--shadow-2);
}

.figure-media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--color-surface-deep);
}

.figure-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure-caption {
  padding: var(--space-2) var(--space-3);
  border-top: var(--border-thick) solid var(--color-ink);
  background: var(--color-surface);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

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

.media-label {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.2;
}

.ratio-16x9 { aspect-ratio: 16 / 9; }
.ratio-4x3 { aspect-ratio: 4 / 3; }
.ratio-1x1 { aspect-ratio: 1 / 1; }
.ratio-3x4 { aspect-ratio: 3 / 4; }
.ratio-21x9 { aspect-ratio: 21 / 9; }

/* ===== 标签切换 ===== */
.tabs {
  background: var(--color-surface);
  border: var(--border-thick) solid var(--color-ink);
  box-shadow: var(--shadow-2);
}

.tab-list {
  display: flex;
  flex-wrap: wrap;
  border-bottom: var(--border-thick) solid var(--color-ink);
}

.tab {
  flex: 0 0 auto;
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface);
  color: var(--color-ink);
  border: 0;
  border-right: var(--border-thick) solid var(--color-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease;
}

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

.tab[aria-selected="true"] {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

.tab-panel {
  padding: var(--space-4);
}

.tab-panel[hidden] { display: none; }

/* ===== 滚动进度 ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  z-index: 200;
  pointer-events: none;
  background: transparent;
}

.scroll-progress-bar {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: var(--color-primary);
}

/* ===== 头部 ===== */
.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-thick) solid transparent;
  backdrop-filter: blur(8px) saturate(130%);
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.site-header[data-scrolled="true"] {
  background: var(--color-surface);
  color: var(--color-ink);
  border-bottom-color: var(--color-ink);
}

.header-inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 300;
  padding: 12px var(--space-3);
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border: var(--border-thick) solid var(--color-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  transition: top 0.18s ease;
}

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

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

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  box-shadow: var(--shadow-1);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1.05;
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: var(--tracking-heading);
}

.brand-sub {
  font-size: var(--text-xs);
  letter-spacing: 0.24em;
  opacity: 0.72;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: 10px 14px;
  background: transparent;
  color: inherit;
  border: var(--border-thick) solid currentColor;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  cursor: pointer;
}

.nav-toggle-text { line-height: 1; }

.nav-toggle-icon {
  position: relative;
  display: inline-block;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle-icon::before { top: -6px; }
.nav-toggle-icon::after { top: 6px; }

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex: 0 1 auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-link {
  display: inline-block;
  padding: 10px var(--space-2);
  border: var(--border-thin) solid transparent;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  color: inherit;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.nav-link:hover {
  border-color: currentColor;
  background: var(--color-primary-soft);
  color: var(--color-ink);
}

.site-header[data-scrolled="true"] .nav-link:hover { color: var(--color-ink); }

.nav-link[aria-current="page"] {
  background: var(--color-accent);
  color: var(--color-accent-ink);
  border-color: var(--color-ink);
}

.nav-contact {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: 3px solid currentColor;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  color: inherit;
}

.nav-contact:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* ===== 页脚 ===== */
.site-footer {
  margin-top: var(--section-y);
  padding-block: var(--space-8) var(--space-4);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: 8px solid var(--color-primary);
}

.footer-inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
}

.footer-brand-name {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-3xl);
  line-height: 0.92;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.footer-brand-sub {
  margin: var(--space-2) 0 0;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.24em;
  color: var(--color-contrast-accent);
}

.footer-hot {
  max-width: 34ch;
  padding-left: var(--space-3);
  border-left: 4px solid var(--color-primary);
}

.footer-hot-label {
  margin: 0 0 4px;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  color: var(--color-contrast-ink);
}

.footer-hot-note {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  opacity: 0.72;
}

.footer-rule {
  height: 0;
  margin-block: var(--space-6);
  border-top: 6px double var(--color-contrast-line);
}

.footer-cols {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr) minmax(0, 1.35fr);
  gap: var(--space-4);
}

.footer-col { min-width: 0; }

.footer-col-title {
  margin: 0 0 var(--space-3);
  padding-bottom: var(--space-1);
  border-bottom: var(--border-thick) solid var(--color-contrast-accent);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  color: var(--color-contrast-ink);
}

.footer-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.footer-list a {
  display: inline-block;
  padding: 6px 0;
  border-bottom: var(--border-thin) solid transparent;
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  transition: color 0.18s ease, border-color 0.18s ease;
}

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

.footer-list-plain li { padding: 6px 0; }

.footer-meta {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-contrast-ink);
  overflow-wrap: anywhere;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
}

.footer-bottom p { margin: 0; }

.footer-line { color: var(--color-contrast-ink); }

.footer-copy {
  font-family: var(--font-mono);
  color: var(--color-contrast-ink);
  opacity: 0.62;
}

.footer-icp {
  font-family: var(--font-mono);
  color: var(--color-contrast-accent);
}

/* ===== 平板 ===== */
@media (max-width: 1080px) {
  .footer-cols { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-col:last-child { grid-column: 1 / -1; }
}

/* ===== 移动导航与堆叠 ===== */
@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: 72vh;
    overflow-y: auto;
    padding: var(--space-2) var(--gutter) var(--space-4);
    background: var(--color-contrast-surface);
    color: var(--color-contrast-ink);
    border-top: var(--border-thick) solid var(--color-contrast-line);
    border-bottom: var(--border-thick) solid var(--color-ink);
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-link {
    display: block;
    padding: 14px 0;
    border: 0;
    border-bottom: var(--border-thin) solid var(--color-contrast-line);
    font-size: var(--text-base);
  }

  .nav-link:hover {
    background: transparent;
    color: var(--color-contrast-accent);
  }

  .nav-link[aria-current="page"] {
    background: var(--color-accent);
    color: var(--color-accent-ink);
    padding-inline: var(--space-2);
  }

  .nav-contact {
    align-self: flex-start;
    margin-top: var(--space-3);
    color: var(--color-contrast-accent);
    border-bottom-color: var(--color-contrast-accent);
  }

  .split { grid-template-columns: minmax(0, 1fr); }
  .grid-9 { grid-template-columns: minmax(0, 1fr); }

  .footer-cols { grid-template-columns: minmax(0, 1fr); }
  .footer-col:last-child { grid-column: auto; }
  .footer-hot { border-left: 0; padding-left: 0; }
}

@media (min-width: 901px) {
  .grid-9 > .span-3 { grid-column: span 3; }
  .grid-9 > .span-4 { grid-column: span 4; }
  .grid-9 > .span-5 { grid-column: span 5; }
  .grid-9 > .span-6 { grid-column: span 6; }
  .grid-9 > .span-7 { grid-column: span 7; }
  .grid-9 > .span-9 { grid-column: span 9; }
}

/* ===== 手机 ===== */
@media (max-width: 640px) {
  :root { --gutter: 16px; }

  .header-inner { min-height: 66px; }
  .brand-mark { width: 38px; height: 38px; font-size: var(--text-base); }
  .brand-sub { display: none; }
  .brand-name { font-size: var(--text-base); }

  .block { padding: var(--space-3); }
  .tab { border-right: 0; border-bottom: var(--border-thin) solid var(--color-ink); width: 100%; text-align: left; }
  .tab-panel { padding: var(--space-3); }

  .datatable,
  .datatable thead,
  .datatable tbody,
  .datatable tr,
  .datatable th,
  .datatable td { display: block; width: 100%; }

  .datatable thead { display: none; }

  .datatable tr {
    margin-bottom: var(--space-2);
    border: var(--border-thin) solid var(--color-ink);
  }

  .datatable td {
    border: 0;
    border-bottom: 1px solid var(--color-line);
    padding: 10px var(--space-2);
  }

  .datatable td:last-child { border-bottom: 0; }

  .num-cell { text-align: left; }

  .footer-brand-name { font-size: var(--text-2xl); }
}

/* ===== 动效偏好 ===== */
@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;
  }

  .block-hover:hover,
  .btn:hover { transform: none; }
}