/* =========================================================
   宝威体育BVTY · 共享样式表 /assets/site.css
   ========================================================= */

:root {
  --color-surface: #fafafa;
  --color-surface-alt: #f1f1f1;
  --color-surface-deep: #e4e5e5;
  --color-ink: #45494f;
  --color-ink-soft: #696f77;
  --color-ink-muted: #797e86;
  --color-line: #d9dadb;
  --color-primary: #4b75b4;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e2e7f0;
  --color-accent: #cf304d;
  --color-accent-ink: #ffffff;
  --color-highlight: #f2d6db;
  --color-focus: #dc2345;
  --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: 10.7px;
  --text-sm: 13.4px;
  --text-base: 15px;
  --text-lg: 18.8px;
  --text-xl: 23.4px;
  --text-2xl: 29.3px;
  --text-3xl: 36.6px;
  --text-4xl: 45.8px;
  --weight-heading: 629;
  --weight-body: 400;
  --leading-body: 1.77;
  --leading-heading: 1.28;
  --tracking-heading: 0.006em;
  --radius-sm: 5px;
  --radius-md: 6px;
  --radius-lg: 7px;
  --radius-pill: 7px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: 0 1px 0 rgba(69, 73, 79, 0.12);
  --shadow-2: 0 2px 0 rgba(69, 73, 79, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1060px;
  --measure: 73ch;
  --gutter: 16px;
  --section-y: 78px;
  --section-y-lg: 109px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

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;
  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);
  color: var(--color-ink);
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); }
button { font: inherit; color: inherit; }
ol, ul { margin: 0; padding: 0; }

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

/* ---------- 中文排版基线 ---------- */
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }
strong { font-weight: var(--weight-heading); }
.num,
[data-num] {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: 6px;
  z-index: 200;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform 160ms ease-out;
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.topbar { position: relative; }

.topbar__inner {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
  min-height: 58px;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: 0 50%;
  z-index: 2;
}

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

.brand__mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand__text { display: flex; flex-direction: column; line-height: 1.2; }
.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
}
.brand__descriptor {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

/* 阶段标签 */
.stage-tag {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin: 0;
  padding: 4px 11px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  background: var(--color-surface-alt);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-soft);
  white-space: nowrap;
  flex: 0 0 auto;
}
.stage-tag__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent) 16%, transparent);
}
.stage-tag__val--key { color: var(--color-ink); font-weight: 700; }
.stage-tag__sep { color: var(--color-line); }

/* 工具区 */
.topbar__tools {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.tool-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 11px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-ink-soft);
  font-size: var(--text-sm);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 160ms ease-out, color 160ms ease-out;
}
.tool-link__key {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.tool-link:hover { border-color: var(--color-primary); color: var(--color-primary); }
.tool-link:hover .tool-link__key { color: var(--color-primary); }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 11px;
  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);
  cursor: pointer;
  transition: border-color 160ms ease-out, background-color 160ms ease-out;
}
.nav-toggle:hover { border-color: var(--color-primary); }
.nav-toggle[aria-expanded="true"] {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
  color: var(--color-primary);
}
.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 14px;
}
.nav-toggle__bars i {
  display: block;
  height: 2px;
  width: 100%;
  background: currentColor;
  border-radius: 1px;
  transition: transform 160ms ease-out, opacity 160ms ease-out;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* ---------- 栏目轨道导航 ---------- */
.rail {
  position: fixed;
  left: 0;
  right: 0;
  top: 58px;
  z-index: 70;
  max-height: calc(100vh - 58px);
  overflow-y: auto;
  padding: var(--space-3) max(var(--space-3), calc((100vw - var(--container)) / 2)) var(--space-4);
  background: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-8px);
  transition: opacity 180ms ease-out, transform 180ms ease-out, visibility 180ms linear;
}
.rail[data-open="true"] {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.rail__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.rail__list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--border-thin);
  background: var(--color-line);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.rail__item { display: block; }

.rail__link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 12px var(--space-3);
  background: var(--color-surface);
  color: var(--color-ink);
  font-size: var(--text-lg);
  text-decoration: none;
  transition: background-color 160ms ease-out, color 160ms ease-out;
}
.rail__link:hover { background: var(--color-surface-alt); color: var(--color-primary); }
.rail__link[aria-current="page"] {
  background: var(--color-primary-soft);
  color: var(--color-primary);
  box-shadow: inset var(--border-thick) 0 0 0 var(--color-primary);
  font-weight: var(--weight-heading);
}
.rail__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  min-width: 2.2em;
}
.rail__link[aria-current="page"] .rail__no { color: var(--color-primary); }
.rail__label { flex: 1 1 auto; }

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: var(--section-y-lg);
  background: var(--color-surface-alt);
  border-top: var(--border-thin) solid var(--color-line);
  padding-block: var(--section-y) var(--space-4);
}

.footer__wrap {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.footer__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);
}
.footer__brand {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.footer__tagline {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

.footer__panels {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--border-thin);
  background: var(--color-line);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.footer-card {
  background: var(--color-surface);
  padding: var(--space-3);
  min-width: 0;
}
.footer-card__title {
  position: relative;
  margin: 0 0 var(--space-2);
  padding-left: 12px;
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.footer-card__title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.2em;
  bottom: 0.2em;
  width: var(--border-thick);
  background: var(--color-primary);
}
.footer-card__list {
  list-style: none;
  display: grid;
  gap: 7px;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  overflow-wrap: anywhere;
}
.footer-card__list li {
  padding-bottom: 7px;
  border-bottom: var(--border-thin) dotted var(--color-line);
}
.footer-card__list li:last-child { padding-bottom: 0; border-bottom: 0; }
.footer-card a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: var(--border-thin) dotted color-mix(in srgb, var(--color-primary) 45%, transparent);
  transition: color 160ms ease-out, border-color 160ms ease-out;
}
.footer-card a:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.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-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.footer__legal,
.footer__meta { margin: 0; }

/* ---------- 布局容器 ---------- */
.u-container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.u-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.u-span-3 { grid-column: span 3; }
.u-span-4 { grid-column: span 4; }
.u-span-5 { grid-column: span 5; }
.u-span-6 { grid-column: span 6; }
.u-span-7 { grid-column: span 7; }
.u-span-8 { grid-column: span 8; }
.u-span-9 { grid-column: span 9; }
.u-span-12 { grid-column: span 12; }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 7px;
  list-style: none;
}
.breadcrumb__list li + li::before {
  content: "/";
  margin-right: 7px;
  color: var(--color-line);
}
.breadcrumb a {
  color: inherit;
  text-decoration: none;
  border-bottom: var(--border-thin) dotted var(--color-line);
}
.breadcrumb a:hover {
  color: var(--color-primary);
  border-bottom-color: currentColor;
}

/* ---------- 区块标题 ---------- */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  margin: 0 0 var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.section-head__title {
  position: relative;
  margin: 0;
  padding-left: 13px;
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
}
.section-head__title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.16em;
  bottom: 0.16em;
  width: var(--border-thick);
  background: var(--color-primary);
}
.section-head__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

/* ---------- 正文 ---------- */
.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  color: var(--color-ink);
}
.prose h2 {
  margin: var(--space-6) 0 var(--space-2);
  padding-left: 13px;
  position: relative;
  font-size: var(--text-xl);
}
.prose h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.16em;
  bottom: 0.16em;
  width: var(--border-thick);
  background: var(--color-primary);
}
.prose h3 {
  margin: var(--space-4) 0 var(--space-1);
  font-size: var(--text-lg);
}
.prose ul,
.prose ol { margin: 0 0 1em; padding-left: 1.3em; }
.prose li { margin-bottom: 6px; }
.prose li::marker { color: var(--color-ink-muted); }
.prose blockquote {
  margin: var(--space-3) 0;
  padding: var(--space-2) var(--space-3);
  border-left: var(--border-thick) solid var(--color-highlight);
  background: color-mix(in srgb, var(--color-highlight) 34%, var(--color-surface));
  color: var(--color-ink-soft);
}
.prose a { color: var(--color-primary); text-decoration: underline; text-underline-offset: 3px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 9px 16px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 160ms ease-out, border-color 160ms ease-out, color 160ms ease-out;
}
.btn:hover { border-color: var(--color-primary); color: var(--color-primary); }
.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) 82%, var(--color-ink));
  border-color: color-mix(in srgb, var(--color-primary) 82%, var(--color-ink));
  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) 84%, var(--color-ink));
  border-color: color-mix(in srgb, var(--color-accent) 84%, var(--color-ink));
  color: var(--color-accent-ink);
}
.btn--ghost { background: transparent; }

/* ---------- 节点标记 ---------- */
.node {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  white-space: nowrap;
}
.node__dot {
  width: 9px;
  height: 9px;
  flex: 0 0 auto;
  border-radius: 50%;
  border: var(--border-thin) solid var(--color-line);
  background: var(--color-surface);
  transition: border-color 200ms ease-out, background-color 200ms ease-out;
}
.node--square .node__dot { border-radius: 1px; }
.node--primary .node__dot { border-color: var(--color-primary); }
.node--accent .node__dot { border-color: var(--color-accent); background: var(--color-accent); }
.node--warn .node__dot {
  border-color: color-mix(in srgb, var(--color-accent) 42%, var(--color-highlight));
  background: var(--color-highlight);
}

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 2px 8px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-ink-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.7;
  white-space: nowrap;
}
.tag--blue {
  background: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 30%, transparent);
  color: var(--color-primary);
}
.tag--red {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.tag--yellow {
  background: var(--color-highlight);
  border-color: color-mix(in srgb, var(--color-accent) 32%, transparent);
  color: color-mix(in srgb, var(--color-accent) 72%, var(--color-ink));
}

/* ---------- 计分牌 ---------- */
.scoreboard {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--border-thin);
  background: var(--color-line);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.scoreboard__cell {
  background: var(--color-surface);
  padding: var(--space-3);
}
.scoreboard__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-4xl);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-ink);
  font-variant-numeric: tabular-nums;
}
.scoreboard__key {
  display: block;
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.scoreboard__cell--accent { background: var(--color-accent); }
.scoreboard__cell--accent .scoreboard__num { color: var(--color-accent-ink); }
.scoreboard__cell--accent .scoreboard__key { color: color-mix(in srgb, var(--color-accent-ink) 78%, transparent); }

/* ---------- 面板 ---------- */
.panel {
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}
.panel--soft {
  background: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 24%, var(--color-line));
}
.panel--alt { background: var(--color-surface-alt); }
.panel--deep { background: var(--color-surface-deep); }
.panel__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: 10px var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.panel__body { padding: var(--space-3); }
.panel__body > :last-child { margin-bottom: 0; }

/* ---------- 数据表 ---------- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.data-table caption {
  text-align: left;
  padding-bottom: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.data-table th,
.data-table td {
  padding: 9px 10px;
  text-align: left;
  vertical-align: top;
  border-bottom: var(--border-thin) dotted var(--color-line);
}
.data-table thead th {
  background: var(--color-surface-deep);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-heading);
  color: var(--color-ink-soft);
  white-space: nowrap;
}
.data-table tbody tr { transition: background-color 160ms ease-out; }
.data-table tbody tr:hover { background: var(--color-highlight); }
.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td { border-bottom: 0; }
.data-table .num { text-align: right; white-space: nowrap; }

/* ---------- 图片与展签 ---------- */
.figure {
  position: relative;
  margin: 0;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  overflow: hidden;
}
.figure__img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--color-surface-deep);
}
.figure__img--tall { aspect-ratio: 4 / 3; }
.figure__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  max-width: 100%;
  padding: 5px 10px;
  background: color-mix(in srgb, var(--color-surface) 88%, transparent);
  border-top: var(--border-thin) solid var(--color-line);
  border-right: var(--border-thin) solid var(--color-line);
  border-top-right-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-soft);
}
.figure__cap b { color: var(--color-ink); font-weight: 700; }

/* ---------- 横向主题带 ---------- */
.band {
  background: var(--color-surface-alt);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
  padding-block: var(--space-4);
}
.band--slice {
  background: var(--color-primary-soft);
  border: 0;
  clip-path: polygon(0 3%, 100% 0, 100% 97%, 0 100%);
  padding-block: var(--space-6);
}
.band--warn {
  background: color-mix(in srgb, var(--color-highlight) 60%, var(--color-surface));
  border-color: color-mix(in srgb, var(--color-accent) 22%, var(--color-line));
}

/* ---------- 时间轴 ---------- */
.timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--space-3) + 1px);
  width: var(--border-thin);
  background: var(--color-line);
}
.timeline__item {
  position: relative;
  padding: var(--space-3) 0 var(--space-3) 56px;
  border-bottom: var(--border-thin) dotted var(--color-line);
  transition: transform 200ms ease-out;
}
.timeline__item:last-child { border-bottom: 0; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: calc(var(--space-3) - 4px);
  top: calc(var(--space-3) + 8px);
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  transition: border-color 200ms ease-out, background-color 200ms ease-out;
}
.timeline__item.is-revealed::before { border-color: var(--color-primary); }
.timeline__item--square::before { border-radius: 1px; }
.timeline__item--red::before { border-color: var(--color-accent); background: var(--color-accent); }
.timeline__item--warn::before {
  border-color: color-mix(in srgb, var(--color-accent) 42%, var(--color-highlight));
  background: var(--color-highlight);
}
.timeline__item--alt { transform: translateX(10px); }

.timeline__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.timeline__title {
  margin: 0 0 6px;
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
}
.timeline__body {
  margin: 0;
  max-width: var(--measure);
  color: var(--color-ink-soft);
}

/* ---------- 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 13px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  cursor: pointer;
  box-shadow: var(--shadow-1);
  opacity: 0;
  visibility: hidden;
  transition: opacity 180ms ease-out, visibility 180ms linear, border-color 160ms ease-out, color 160ms ease-out;
}
.to-top.is-on { opacity: 1; visibility: visible; }
.to-top:hover { border-color: var(--color-primary); color: var(--color-primary); }

/* ---------- 显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 240ms ease-out, transform 240ms ease-out;
}
[data-reveal].is-revealed { opacity: 1; transform: none; }

/* ---------- 断点 ---------- */
@media (min-width: 900px) {
  .timeline::before { left: 25%; }
  .timeline__item { padding-left: calc(25% + var(--space-4)); }
  .timeline__item::before { left: calc(25% - 5px); }
  .timeline__item--alt { transform: translateX(-10px); }
}

@media (min-width: 1320px) {
  .nav-toggle { display: none; }
  .rail {
    position: fixed;
    left: var(--space-3);
    right: auto;
    top: calc(58px + var(--space-4));
    width: 96px;
    padding: 0;
    max-height: none;
    overflow: visible;
    background: transparent;
    border-bottom: 0;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
    transition: none;
  }
  .rail__title {
    margin-bottom: var(--space-2);
    color: var(--color-ink-muted);
  }
  .rail__list {
    gap: 2px;
    background: transparent;
    border: 0;
    border-left: var(--border-thin) solid var(--color-line);
    border-radius: 0;
    overflow: visible;
  }
  .rail__link {
    flex-direction: column;
    align-items: flex-start;
    gap: 1px;
    margin-left: -1px;
    padding: 7px 8px 7px 11px;
    border-left: var(--border-thick) solid transparent;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: transparent;
    font-size: var(--text-sm);
    line-height: 1.35;
  }
  .rail__link:hover { background: var(--color-surface-alt); color: var(--color-primary); }
  .rail__link[aria-current="page"] {
    border-left-color: var(--color-primary);
    background: var(--color-primary-soft);
    box-shadow: none;
  }
  .rail__no { font-size: 10px; min-width: 0; }
}

@media (max-width: 1100px) {
  .footer__panels { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 820px) {
  :root { --section-y: 56px; --section-y-lg: 72px; }
  .stage-tag { display: none; }
  .u-span-3,
  .u-span-4,
  .u-span-5,
  .u-span-6,
  .u-span-7,
  .u-span-8,
  .u-span-9 { grid-column: span 12; }
  .site-footer { padding-block: var(--section-y) var(--space-3); }
}

@media (max-width: 620px) {
  .tool-link__txt { display: none; }
  .brand__descriptor { display: none; }
  .footer__panels { grid-template-columns: 1fr; }
  .footer__brand { font-size: var(--text-lg); }
  .rail__link { font-size: var(--text-base); }
  .footer__base { flex-direction: column; align-items: flex-start; }
}

/* ---------- 无障碍动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .timeline__item--alt { transform: none; }
  .rail { transition: none; }
}