:root {
  --color-surface: #fafafa;
  --color-surface-alt: #f0f0f0;
  --color-surface-deep: #e3e2e2;
  --color-ink: #37312f;
  --color-ink-soft: #685e5a;
  --color-ink-muted: #827772;
  --color-line: #d7d6d5;
  --color-primary: #ce470e;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #f4e1d9;
  --color-accent: #1876ce;
  --color-accent-ink: #ffffff;
  --color-highlight: #d1e2f2;
  --color-focus: #0c71cf;
  --color-contrast-surface: #1a0f0b;
  --color-contrast-ink: #e7e5e4;
  --color-contrast-line: #473e3b;
  --color-contrast-accent: #1b83e4;
  --overlay-scrim: linear-gradient(180deg, rgba(26, 15, 11, 0.35) 0%, rgba(26, 15, 11, 0.72) 55%, rgba(26, 15, 11, 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(57px, 11.6vw, 149px);
  --text-figure: clamp(47px, 8.4vw, 107px);
  --weight-heading: 849;
  --weight-body: 400;
  --leading-body: 1.74;
  --leading-heading: 1.28;
  --tracking-heading: -0.011em;
  --radius-sm: 1px;
  --radius-md: 2px;
  --radius-lg: 2px;
  --radius-pill: 2px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1120px;
  --measure: 67ch;
  --gutter: 32px;
  --section-y: 103px;
  --section-y-lg: 144px;
}

/* =========================================================
   美博体育 · 共享样式表 /assets/site.css
   双色海报体系：章节底色反相，边界只靠色差与留白
   ========================================================= */

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

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

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;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}

p, figure, blockquote, dl, dd, dt { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img, picture, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; margin: 0; height: 0; }

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

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

/* ---------- 容器与栅格 ---------- */
.wrap,
.header-inner,
.footer-inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid { display: grid; gap: var(--gutter); }
.grid--6 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }

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

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

/* ---------- 色块分区 ---------- */
.band {
  padding-block: var(--section-y);
}
.band--lg { padding-block: var(--section-y-lg); }
.band--tight { padding-block: var(--space-8); }
.band--primary { background: var(--color-primary); color: var(--color-primary-ink); }
.band--contrast { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.band--alt { background: var(--color-surface-alt); color: var(--color-ink); }
.band--deep { background: var(--color-surface-deep); color: var(--color-ink); }
.band--surface { background: var(--color-surface); color: var(--color-ink); }

.band--primary a { color: var(--color-primary-ink); }
.band--contrast a { color: var(--color-contrast-accent); }
.band--primary .eyebrow,
.band--primary .stat-value { color: var(--color-primary-ink); }
.band--contrast .eyebrow { color: var(--color-contrast-accent); }
.band--contrast .stat-value { color: var(--color-contrast-accent); }
.band--contrast .stat-label,
.band--contrast .figure-label {
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}

.band-slant {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 64px), 0 100%);
  padding-block-end: calc(var(--section-y) + 64px);
}
.band-slant.band--lg {
  padding-block-end: calc(var(--section-y-lg) + 64px);
}

/* ---------- 文字层级工具 ---------- */
.display {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 0.98;
  letter-spacing: -0.032em;
  color: inherit;
}

.figure-value {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-figure);
  line-height: 0.92;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}
.figure-value--primary { color: var(--color-primary); }
.figure-value--ink { color: var(--color-ink); }

.stat { display: flex; flex-direction: column; gap: var(--space-1); }
.stat-value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-xl);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}
.stat-label {
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--color-ink-muted);
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.18em;
  line-height: 1.3;
  color: var(--color-accent);
}

.quote-block {
  position: relative;
  margin-block: var(--space-6);
  padding: var(--space-4) var(--space-4) var(--space-4) calc(var(--space-6) + 30px);
  background: var(--color-primary-soft);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-lg);
  line-height: 1.5;
  letter-spacing: -0.008em;
  border-radius: var(--radius-sm);
}
.quote-block::before {
  content: "\201C";
  position: absolute;
  left: var(--space-4);
  top: calc(var(--space-2));
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-primary);
}
.band--primary .quote-block {
  background: color-mix(in srgb, var(--color-primary-ink) 92%, transparent);
  color: var(--color-ink);
}
.band--contrast .quote-block {
  background: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.band--contrast .quote-block::before { color: var(--color-contrast-accent); }

/* ---------- 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 13px 22px;
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-md);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  line-height: 1.2;
  transition: background-color 0.24s ease, color 0.24s ease, border-color 0.24s ease;
}
.btn:hover { background: var(--color-primary-ink); color: var(--color-primary); }

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

.btn--ghost {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn--ghost:hover { background: var(--color-primary); color: var(--color-primary-ink); }

.band--contrast .btn {
  background: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}
.band--contrast .btn:hover {
  background: var(--color-contrast-ink);
  border-color: var(--color-contrast-ink);
  color: var(--color-contrast-surface);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 14px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  line-height: 1;
  white-space: nowrap;
  transition: background-color 0.22s ease, color 0.22s ease;
}
.chip:hover {
  background: var(--color-surface);
  color: var(--color-primary);
  outline: var(--border-thin) solid var(--color-primary);
  outline-offset: -1px;
}
.chip--accent { background: var(--color-accent); color: var(--color-accent-ink); }
.chip--accent:hover {
  background: var(--color-surface);
  color: var(--color-accent);
  outline-color: var(--color-accent);
}

.tag {
  display: inline-block;
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-highlight);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  line-height: 1.3;
}
.band--contrast .tag {
  background: color-mix(in srgb, var(--color-contrast-accent) 26%, var(--color-contrast-surface));
  color: var(--color-contrast-ink);
}

/* ---------- 内容卡 ---------- */
.card {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4);
  background: var(--color-surface-deep);
  color: var(--color-ink);
  border-radius: var(--radius-sm);
}
.card--primary { background: var(--color-primary); color: var(--color-primary-ink); }
.card--primary .stat-label,
.card--primary .figure-label { color: color-mix(in srgb, var(--color-primary-ink) 78%, transparent); }
.card--accent { background: var(--color-accent); color: var(--color-accent-ink); }
.card--accent .stat-label { color: color-mix(in srgb, var(--color-accent-ink) 82%, transparent); }
.card--soft { background: var(--color-surface-alt); }

/* ---------- 正文 ---------- */
.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 { font-size: var(--text-2xl); margin-top: var(--space-6); }
.prose h3 { font-size: var(--text-xl); margin-top: var(--space-6); }
.prose li + li { margin-top: var(--space-1); }
.prose ul li { padding-left: var(--space-3); position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 8px;
  height: 2px;
  background: var(--color-primary);
}
.prose a { color: var(--color-accent); }
.prose a:hover { text-decoration: underline; text-underline-offset: 3px; }
.band--contrast .prose { color: var(--color-contrast-ink); }
.band--contrast .prose a { color: var(--color-contrast-accent); }

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}
.breadcrumbs li { display: flex; align-items: center; gap: var(--space-1); }
.breadcrumbs li + li::before {
  content: "/";
  color: var(--color-ink-muted);
  opacity: 0.55;
}
.breadcrumbs a { color: var(--color-ink-soft); }
.breadcrumbs a:hover { color: var(--color-primary); }

/* ---------- 图片容器 ---------- */
.figure-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--color-surface-deep);
  border: var(--border-thick) solid var(--color-primary);
  border-radius: var(--radius-sm);
}
.figure-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure-frame--square { aspect-ratio: 1 / 1; }
.figure-frame--tall { aspect-ratio: 3 / 4; }
.figure-frame--wide { aspect-ratio: 21 / 9; }
.figure-frame--accent { border-color: var(--color-accent); }
.figure-frame--flat { border-color: var(--color-surface-deep); }

.figure-frame--overlay::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.figure-cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  padding: var(--space-4);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.6;
}
.figure-label {
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

/* ---------- 页头 ---------- */
.skip-link {
  position: fixed;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 120;
  transform: translateY(calc(-100% - var(--space-4)));
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  transition: transform 0.2s ease;
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--color-surface);
}

.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-3);
  padding-block: var(--space-3);
  transition: padding 0.28s ease;
}

.masthead-side {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 0;
}
.masthead-side--start { justify-content: flex-start; }
.masthead-side--end { justify-content: flex-end; }

.masthead-center { min-width: 0; }

.masthead-brand {
  display: block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: 1.08;
  letter-spacing: 0.05em;
  color: var(--color-ink);
  text-align: center;
  transition: font-size 0.28s ease, color 0.2s ease;
}
.masthead-brand:hover { color: var(--color-primary); }

.masthead-tag {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.32em;
  text-indent: 0.32em;
  line-height: 1.4;
  color: var(--color-ink-muted);
  text-align: center;
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border-radius: var(--radius-sm);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  line-height: 1;
  transition: background-color 0.22s ease, color 0.22s ease;
}
.nav-toggle:hover {
  background: var(--color-contrast-ink);
  color: var(--color-contrast-surface);
}
.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: currentColor;
}
.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }
.nav-toggle-text { display: inline-block; }

.nav-bar {
  display: block;
  background: var(--color-primary);
}

.nav-list {
  display: flex;
  justify-content: center;
  align-items: stretch;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.nav-list a {
  display: block;
  padding: 14px 18px;
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  line-height: 1.3;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease;
}
.nav-list a:hover,
.nav-list a[aria-current="page"] {
  background: var(--color-primary-ink);
  color: var(--color-primary);
}

.site-header.is-condensed .masthead { padding-block: var(--space-1); }
.site-header.is-condensed .masthead-brand { font-size: var(--text-lg); }
.site-header.is-condensed .masthead-tag { display: none; }
.site-header.is-condensed .chip { display: none; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--color-surface-alt);
  color: var(--color-ink);
}

.footer-band {
  height: var(--space-3);
  background: var(--color-primary);
}

.footer-inner {
  padding-block: var(--space-8) var(--space-6);
}

.footer-brand { max-width: 52ch; }

.footer-brand-name {
  display: inline-block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: 1.1;
  letter-spacing: 0.05em;
  color: var(--color-ink);
  transition: color 0.2s ease;
}
.footer-brand-name:hover { color: var(--color-primary); }

.footer-brand-note {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

.footer-index {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--space-6) var(--space-4);
  margin-top: var(--space-8);
}

.footer-col-title {
  margin-bottom: var(--space-2);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.18em;
  color: var(--color-primary);
}

.footer-col li + li { margin-top: var(--space-1); }

.footer-col a,
.footer-col span {
  display: inline-block;
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-ink-soft);
  transition: color 0.2s ease;
}
.footer-col a:hover { color: var(--color-primary); }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2) var(--space-6);
  margin-top: var(--space-8);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-muted);
}
.footer-legal-main { max-width: 62ch; }
.footer-legal-year { white-space: nowrap; }

/* ---------- 动效与状态 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.26s ease, transform 0.26s ease, visibility 0.26s ease,
              background-color 0.22s ease, color 0.22s ease;
}
.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.to-top:hover {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

/* ---------- 平板 ---------- */
@media (max-width: 900px) {
  html { scroll-padding-top: 112px; }

  .grid--6,
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .col-3,
  .col-4,
  .col-6 { grid-column: span 2; }
  .col-2 { grid-column: span 1; }

  .band { padding-block: var(--space-8); }
  .band--lg { padding-block: var(--space-8); }

  .masthead { padding-block: var(--space-2); }
  .masthead-tag { display: none; }

  .nav-toggle { display: inline-flex; }

  .nav-bar { display: none; }
  .nav-bar[data-open] { display: block; }

  .nav-list {
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    max-width: var(--container);
    padding-inline: var(--gutter);
    padding-block: var(--space-1);
  }
  .nav-list a {
    padding: 15px var(--space-2);
    font-size: var(--text-base);
    letter-spacing: 0.06em;
  }

  .footer-index {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: var(--space-6);
  }

  .band-slant {
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 40px), 0 100%);
    padding-block-end: calc(var(--space-8) + 40px);
  }
  .band-slant.band--lg { padding-block-end: calc(var(--space-8) + 40px); }
}

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

  .wrap,
  .header-inner,
  .footer-inner,
  .nav-list { padding-inline: var(--space-3); }

  .grid--2,
  .grid--3,
  .grid--6 { grid-template-columns: minmax(0, 1fr); }
  .col-2,
  .col-3,
  .col-4,
  .col-6 { grid-column: span 1; }

  .masthead {
    grid-template-columns: 1fr auto;
    gap: var(--space-2);
  }
  .masthead-side--start { display: none; }
  .masthead-side--end .chip { display: none; }
  .masthead-center { text-align: left; }
  .masthead-brand { text-align: left; font-size: var(--text-lg); }

  .quote-block {
    padding: var(--space-3) var(--space-3) var(--space-3) calc(var(--space-3) + 26px);
    font-size: var(--text-base);
  }
  .quote-block::before { left: var(--space-3); top: var(--space-2); font-size: var(--text-xl); }

  .footer-index { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-4) var(--space-3); }
  .footer-inner { padding-block: var(--space-6) var(--space-4); }
  .footer-legal { flex-direction: column; align-items: flex-start; margin-top: var(--space-6); }

  .to-top { right: var(--space-2); bottom: var(--space-2); }
}

@media (max-width: 420px) {
  .footer-index { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 降低动效 ---------- */
@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;
    scroll-behavior: auto !important;
  }

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