/* ==========================================================================
   B体育主站 — 共享样式表 /assets/site.css
   夜场竞速 × 数据仪表盘｜粗野主义海报分层
   ========================================================================== */

/* ---------- 1. reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body, h1, h2, h3, h4, h5, h6, p, ul, ol, li, figure, figcaption, blockquote, dl, dd { margin: 0; }

ul, ol { padding: 0; list-style: none; }

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

button, input, select, textarea { font: inherit; color: inherit; }

button { background: none; border: 0; }

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

table { border-collapse: collapse; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #07110E;
  --ink-deep: #04100C;
  --panel: #0E1F1A;
  --line: #1E3A32;
  --cyan: #2FF3D0;
  --cyan-deep: #17A98F;
  --flare: #FF4B1F;
  --paper: #F2F5F3;
  --muted: #9BB0A8;
  --amber: #FFC24B;

  --shell: 1264px;
  --gutter: 20px;

  --bd: 2px;
  --shadow: 8px 8px 0 0 var(--ink-deep);
  --shadow-hover: 10px 10px 0 0 var(--ink-deep);

  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", ui-monospace, "Cascadia Mono", Menlo, Consolas, monospace;

  --t-fast: 180ms;
  --t-mid: 280ms;
  --t-slow: 320ms;
}

/* ---------- 3. 中文排版基线 ---------- */
body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  color: var(--paper);
  background-color: var(--ink);
  background-image: repeating-linear-gradient(
    115deg,
    rgba(47, 243, 208, 0.035) 0 1px,
    transparent 1px 28px
  );
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}

p { text-wrap: pretty; }

strong { font-weight: 700; }

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

[id] { scroll-margin-top: 128px; }

/* ---------- 4. 布局骨架 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(48px, 7vw, 96px); }
.section--tight { padding-block: clamp(28px, 4vw, 48px); }

.section--panel {
  background: var(--panel);
  border-block: var(--bd) solid var(--line);
}

.section--rule { border-top: var(--bd) solid var(--line); }

.section__head {
  display: grid;
  gap: 14px;
  max-width: 74ch;
  margin-bottom: clamp(24px, 3.5vw, 44px);
}

.section__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.12;
  letter-spacing: -0.01em;
}

.section__lead {
  color: var(--muted);
  max-width: 62ch;
}

/* 字号层级 12 / 14 / 16 / 20 / 28 / 40 / 64 / 96 */
.display-xl,
.display-lg,
.display-md {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

.display-xl { font-size: clamp(44px, 9vw, 96px); }
.display-lg { font-size: clamp(34px, 6vw, 64px); }
.display-md { font-size: clamp(26px, 4vw, 40px); }

.idx,
.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  display: inline-block;
  width: 22px;
  height: 8px;
  margin-right: 10px;
  background: var(--flare);
  transform: translateY(-2px) skewX(-18deg);
}

/* 栅格 */
.grid { display: grid; gap: clamp(16px, 2.4vw, 28px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.split {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: 0;
}

.split > *:first-child { padding-right: clamp(18px, 3vw, 40px); }

.split > * + * {
  border-left: var(--bd) solid var(--cyan);
  padding-left: clamp(18px, 3vw, 40px);
}

/* ---------- 5. 正文容器 ---------- */
.prose {
  max-width: 72ch;
  font-size: 17px;
  line-height: 1.75;
}

.prose p + p { margin-top: 1.2em; }

.prose h3 {
  font-size: 20px;
  line-height: 1.4;
  margin-top: 1.8em;
  margin-bottom: 0.6em;
}

.prose ul { margin-top: 0.8em; }

.prose li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 0.5em;
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 8px;
  background: var(--cyan);
  transform: rotate(45deg);
}

/* ---------- 6. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -120px;
  z-index: 300;
  padding: 12px 20px;
  background: var(--cyan);
  color: #04140F;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  border: var(--bd) solid var(--ink);
}

.skip-link:focus { top: 12px; }

/* ---------- 7. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: var(--ink);
  border-bottom: var(--bd) solid var(--line);
}

.status-band {
  max-height: 120px;
  overflow: hidden;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  transition: max-height var(--t-mid) ease, opacity var(--t-mid) ease;
}

.site-header[data-stuck] .status-band {
  max-height: 0;
  opacity: 0;
}

.status-band__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 6px 28px;
  padding-block: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.status-band__brand { color: var(--cyan); }

.status-band__meta { display: flex; flex-wrap: wrap; gap: 6px 20px; }

.status-band__meta li { display: flex; align-items: center; gap: 8px; }

.status-band__meta li::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--cyan-deep);
  transform: rotate(45deg);
  flex: 0 0 6px;
}

.nav-band { background: var(--ink); }

.site-header[data-stuck] .nav-band { box-shadow: 0 6px 0 0 var(--ink-deep); }

.nav-band__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 24px;
  padding-block: 14px;
  min-height: 72px;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}

.brand__mark {
  width: 42px;
  height: 42px;
  flex: 0 0 42px;
  display: grid;
  place-items: center;
  background: var(--cyan);
  color: #04140F;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 22px;
  line-height: 1;
  clip-path: polygon(12% 0, 100% 0, 88% 100%, 0 100%);
}

.brand__text {
  display: grid;
  gap: 2px;
  line-height: 1.15;
}

.brand__text strong {
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.brand__text small {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

/* 主导航 */
.main-nav { margin-left: auto; }

.main-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.main-nav__list a {
  display: block;
  padding: 10px 13px;
  font-size: 15px;
  font-weight: 500;
  color: var(--paper);
  border-bottom: var(--bd) solid transparent;
  transition: color var(--t-fast) ease, border-color var(--t-fast) ease;
}

.main-nav__list a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.main-nav__list a[aria-current="page"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.nav-band__tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

.round-chip {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  white-space: nowrap;
}

.round-chip__value { color: var(--amber); font-weight: 700; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  padding: 10px 14px;
  border: var(--bd) solid var(--line);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  cursor: pointer;
  transition: border-color var(--t-fast) ease, color var(--t-fast) ease;
}

.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }

.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--cyan);
}

.nav-toggle__label { margin-left: 2px; }

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: var(--bd) solid var(--line);
  background: transparent;
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: transform var(--t-fast) ease, box-shadow var(--t-fast) ease,
    border-color var(--t-fast) ease, color var(--t-fast) ease, background-color var(--t-fast) ease;
}

.btn:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0 0 var(--cyan-deep);
}

.btn:active { transform: translate(0, 0); box-shadow: none; }

.btn--sm { padding: 8px 14px; font-size: 12px; }

.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #04140F;
  font-weight: 700;
  box-shadow: 6px 6px 0 0 var(--cyan-deep);
}

.btn--primary:hover {
  background: var(--cyan);
  color: #04140F;
  border-color: var(--cyan);
  transform: translate(-2px, -2px);
  box-shadow: 8px 8px 0 0 var(--cyan-deep);
}

.btn--flare {
  background: var(--flare);
  border-color: var(--flare);
  color: #140500;
  font-weight: 700;
  box-shadow: 6px 6px 0 0 #8F2409;
}

.btn--flare:hover {
  background: var(--flare);
  color: #140500;
  border-color: var(--flare);
  transform: translate(-2px, -2px);
  box-shadow: 8px 8px 0 0 #8F2409;
}

.btn--ghost { color: var(--muted); }

/* ---------- 9. 通用组件 ---------- */
.panel {
  background: var(--panel);
  border: var(--bd) solid var(--line);
  padding: clamp(20px, 2.6vw, 32px);
  box-shadow: var(--shadow);
  transition: border-color var(--t-fast) ease, box-shadow var(--t-fast) ease;
}

.panel:hover {
  border-color: var(--cyan);
  box-shadow: var(--shadow-hover);
}

.panel--flare { border-color: var(--flare); }

.panel--flare:hover { border-color: var(--flare); }

.stat { display: grid; gap: 6px; }

.stat__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(32px, 5vw, 64px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.stat--flare .stat__value { color: var(--flare); }

.stat__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.tag--cyan { border-color: var(--cyan); color: var(--cyan); }
.tag--amber { border-color: var(--amber); color: var(--amber); }

/* 面包屑 */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.breadcrumb a { transition: color var(--t-fast) ease; }
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb__sep { color: var(--line); }
.breadcrumb [aria-current="page"] { color: var(--paper); }

/* 章节索引条 */
.index-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  padding-block: 14px;
  border-top: var(--bd) solid var(--line);
  border-bottom: var(--bd) solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.index-bar a {
  color: var(--muted);
  border-bottom: var(--bd) solid transparent;
  padding-bottom: 2px;
  transition: color var(--t-fast) ease, border-color var(--t-fast) ease;
}

.index-bar a:hover { color: var(--paper); }

.index-bar a[aria-current="true"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* 图片容器 */
.figure {
  position: relative;
  overflow: hidden;
  border: var(--bd) solid var(--line);
  background: var(--panel);
}

.figure__media,
.figure__slot {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background-color: var(--panel);
  transition: transform var(--t-slow) ease;
}

.figure__slot {
  display: grid;
  place-items: center;
  background-image:
    repeating-linear-gradient(135deg, rgba(47, 243, 208, 0.08) 0 2px, transparent 2px 16px),
    repeating-linear-gradient(45deg, rgba(255, 75, 31, 0.06) 0 2px, transparent 2px 44px);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.figure--portrait .figure__media,
.figure--portrait .figure__slot { aspect-ratio: 4 / 5; }

.figure--square .figure__media,
.figure--square .figure__slot { aspect-ratio: 1 / 1; }

.figure--slanted { clip-path: polygon(0 0, 100% 0, 100% 100%, 0 88%); }

.figure__caption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.figure:hover .figure__media { transform: scale(1.02); }

/* 时间轴 */
.timeline {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(160px, 1fr);
  overflow-x: auto;
  border-bottom: var(--bd) solid var(--line);
}

.timeline__node {
  position: relative;
  padding: 22px 18px 18px;
  border-left: var(--bd) solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.timeline__node:first-child { border-left: 0; }

.timeline__node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 10px;
  height: 10px;
  background: var(--cyan-deep);
  transform: translate(-50%, -50%) rotate(45deg);
}

.timeline__node--current { color: var(--paper); }

.timeline__node--current::before { background: var(--flare); }

/* 数据表 */
.data-table {
  width: 100%;
  font-size: 15px;
}

.data-table th,
.data-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: baseline;
}

.data-table thead th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
  border-bottom: var(--bd) solid var(--cyan);
}

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

.data-table tbody tr { transition: background-color var(--t-fast) ease; }

.data-table tbody tr:hover { background: rgba(47, 243, 208, 0.06); }

/* 分段切换 */
.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 24px;
  border-bottom: var(--bd) solid var(--line);
}

.tabs__tab {
  padding: 12px 2px;
  margin-bottom: -2px;
  border-bottom: var(--bd) solid transparent;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--muted);
  cursor: pointer;
  transition: color var(--t-fast) ease, border-color var(--t-fast) ease;
}

.tabs__tab:hover { color: var(--paper); }

.tabs__tab[aria-selected="true"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.tabs__panel { padding-top: 24px; }

.tabs__panel[hidden] { display: none; }

/* 手风琴 */
.accordion { border-top: var(--bd) solid var(--line); }

.accordion__item { border-bottom: 1px solid var(--line); }

.accordion__trigger {
  width: 100%;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 0;
  text-align: left;
  font-size: 17px;
  font-weight: 600;
  color: var(--paper);
  cursor: pointer;
  transition: color var(--t-fast) ease;
}

.accordion__trigger:hover { color: var(--cyan); }

.accordion__mark {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--cyan);
  flex: 0 0 auto;
}

.accordion__panel { padding-bottom: 20px; color: var(--muted); }

.accordion__panel[hidden] { display: none; }

/* ---------- 10. 页脚 ---------- */
.site-footer {
  background: var(--ink);
  border-top: var(--bd) solid var(--line);
}

.footer-rail {
  background: var(--panel);
  border-bottom: var(--bd) solid var(--line);
}

.footer-rail__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  padding-block: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.footer-rail__mark { color: var(--cyan); }

.footer-rail__note { color: var(--muted); }

.footer-main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: clamp(28px, 4vw, 56px);
  padding-block: clamp(36px, 5vw, 56px);
}

.footer-brand { display: grid; gap: 18px; align-content: start; }

.footer-brand__desc {
  max-width: 36ch;
  font-size: 15px;
  color: var(--muted);
}

.footer-brand .btn { justify-self: start; }

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 32px);
}

.footer-col__title {
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: var(--bd) solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-col__list li + li { margin-top: 9px; }

.footer-col__list a {
  font-size: 15px;
  color: var(--muted);
  transition: color var(--t-fast) ease;
}

.footer-col__list a:hover { color: var(--cyan); }

.footer-legal {
  background: var(--ink-deep);
  border-top: var(--bd) solid var(--line);
}

.footer-legal__inner {
  display: grid;
  gap: 8px;
  padding-block: 24px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.8;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.footer-legal__row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
}

.footer-legal a {
  border-bottom: 1px solid var(--line);
  transition: color var(--t-fast) ease, border-color var(--t-fast) ease;
}

.footer-legal a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.footer-legal__contact { word-break: break-word; }

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

.footer-legal__copy { color: var(--muted); }

/* ---------- 11. 脚本注入元素 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 200;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--amber) 55%, var(--flare));
  pointer-events: none;
}

.to-top {
  position: fixed;
  right: 20px;
  bottom: 22px;
  z-index: 180;
  padding: 10px 16px;
  border: var(--bd) solid var(--cyan);
  background: var(--panel);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  box-shadow: 6px 6px 0 0 var(--ink-deep);
  cursor: pointer;
  transition: background-color var(--t-fast) ease, color var(--t-fast) ease;
}

.to-top[hidden] { display: none; }

.to-top:hover { background: var(--cyan); color: #04140F; }

/* 入场显现 */
.reveal.is-armed { transition: opacity var(--t-mid) ease, transform var(--t-mid) ease; }

.reveal.is-armed:not(.is-in) {
  opacity: 0;
  transform: translateY(16px);
}

/* ---------- 12. 响应式 ---------- */
@media (max-width: 1080px) {
  .main-nav__list a { padding: 10px 10px; font-size: 14px; }
  .round-chip { display: none; }
}

@media (max-width: 980px) {
  .nav-toggle { display: inline-flex; }

  .main-nav {
    order: 5;
    flex: 1 1 100%;
    margin-left: 0;
    display: none;
    border-top: var(--bd) solid var(--line);
  }

  .site-header[data-open] .main-nav {
    display: block;
    animation: nav-drop var(--t-mid) ease both;
  }

  .site-header[data-open] .nav-toggle {
    border-color: var(--cyan);
    color: var(--cyan);
  }

  .main-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding-block: 6px;
  }

  .main-nav__list a {
    padding: 14px 4px;
    border-bottom: 1px solid var(--line);
    border-left: var(--bd) solid transparent;
    font-size: 16px;
  }

  .main-nav__list a:hover,
  .main-nav__list a[aria-current="page"] {
    border-bottom-color: var(--line);
    border-left-color: var(--cyan);
    padding-left: 14px;
  }

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

  .split > *:first-child { padding-right: 0; }

  .split > * + * {
    border-left: 0;
    border-top: var(--bd) solid var(--cyan);
    padding-left: 0;
    padding-top: clamp(20px, 3vw, 32px);
    margin-top: clamp(20px, 3vw, 32px);
  }

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

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

@keyframes nav-drop {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }

  .nav-band__tools .btn { padding: 8px 12px; font-size: 11px; }

  .status-band__meta { gap: 4px 14px; }

  .footer-cols { grid-template-columns: minmax(0, 1fr); gap: 26px; }

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

  .index-bar { gap: 8px 16px; }

  .data-table th,
  .data-table td { padding: 10px 10px; }

  .to-top { right: 14px; bottom: 14px; padding: 9px 13px; }
}

@media (max-width: 480px) {
  :root { --gutter: 16px; }

  .brand__mark { width: 36px; height: 36px; flex-basis: 36px; font-size: 18px; }

  .brand__text strong { font-size: 15px; }

  .nav-band__tools { display: none; }
}

/* ---------- 13. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}