/* ============================================================
   星空体育中国站 · /assets/site.css
   深夜到清晨 · 蓝图网格 · 专题研究板
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: #05070F;
}

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

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

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

button { font: inherit; color: inherit; }

a { color: inherit; }

/* --- 2. 设计变量 --- */
:root {
  --ink: #05070F;
  --deep: #0B1220;
  --panel: #131C31;
  --line: #22304C;

  --orange: #FF7A2F;
  --orange-soft: #FFB77A;
  --cyan: #2FE3D2;
  --cyan-soft: #9BF4E9;
  --white: #F4F7FF;
  --gray: #93A1BF;
  --yellow: #F5C451;

  --font: "Noto Sans SC", "HarmonyOS Sans SC", "PingFang SC", system-ui, sans-serif;
  --mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, monospace;

  --shell: 1280px;
  --gutter: 24px;
  --radius: 22px;
  --radius-soft: 28px 18px 30px 16px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* --- 3. 基底与中文排版 --- */
body {
  min-height: 100vh;
  font-family: var(--font);
  font-weight: 300;
  font-size: 16px;
  line-height: 1.75;
  color: #E4EBFB;
  background-color: var(--ink);
  background-image:
    radial-gradient(1.6px 1.6px at 24px 32px, rgba(244, 247, 255, .40), transparent 100%),
    radial-gradient(1.4px 1.4px at 96px 78px, rgba(155, 244, 233, .28), transparent 100%),
    radial-gradient(880px 520px at 92% -12%, rgba(255, 122, 47, .16), transparent 62%),
    radial-gradient(760px 520px at -6% 8%, rgba(47, 227, 210, .12), transparent 60%),
    linear-gradient(rgba(34, 48, 76, .28) 1px, transparent 1px),
    linear-gradient(90deg, rgba(34, 48, 76, .28) 1px, transparent 1px);
  background-size: 180px 180px, 240px 240px, auto, auto, 112px 112px, 112px 112px;
  background-repeat: repeat, repeat, no-repeat, no-repeat, repeat, repeat;
}

h1, h2, h3, h4 {
  font-weight: 850;
  letter-spacing: -.01em;
  line-height: 1.18;
  color: var(--white);
  text-wrap: balance;
}

::selection {
  background: rgba(255, 122, 47, .32);
  color: var(--white);
}

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 6px;
}

#main-content {
  display: block;
  scroll-margin-top: 128px;
}

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

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}

.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

/* --- 5. 跳转链接 --- */
.skip-link {
  position: fixed;
  left: 16px;
  top: -72px;
  z-index: 200;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 700;
  color: #180800;
  background: var(--orange);
  border-radius: 0 0 12px 12px;
  text-decoration: none;
  transition: top .2s var(--ease);
}

.skip-link:focus {
  top: 0;
}

/* --- 6. 头部：左右分置 --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(5, 7, 15, .90);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--cyan-soft) 45%, var(--orange));
  transform: scaleX(0);
  transform-origin: left center;
}

.header-shell {
  display: grid;
  grid-template-columns: minmax(212px, 280px) minmax(0, 1fr);
  align-items: center;
  gap: 32px;
  padding-block: 18px;
  transition: padding .24s var(--ease);
}

.brand-rail {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-right: 24px;
  border-right: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  position: relative;
  flex: 0 0 auto;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background:
    radial-gradient(circle at 30% 28%, rgba(255, 183, 122, .95), rgba(255, 122, 47, .22) 44%, transparent 64%),
    radial-gradient(circle at 72% 74%, rgba(47, 227, 210, .88), rgba(47, 227, 210, .14) 48%, transparent 68%),
    var(--deep);
  transition: width .24s var(--ease), height .24s var(--ease);
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 7px;
  border: 1px solid rgba(244, 247, 255, .30);
  border-radius: 50%;
  clip-path: polygon(0 46%, 100% 46%, 100% 100%, 0 100%);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand-name {
  font-size: 18px;
  font-weight: 850;
  letter-spacing: -.01em;
  color: var(--white);
}

.brand-tagline {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .10em;
  color: var(--gray);
}

.rail-coord {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--gray);
}

.rail-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(47, 227, 210, .16);
  animation: railPulse 4.5s ease-in-out infinite;
}

@keyframes railPulse {
  0%, 100% { opacity: .45; }
  50% { opacity: 1; }
}

/* 导航 */
.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: wrap;
}

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 9px 14px;
  font-size: 14.5px;
  color: var(--gray);
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 999px;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.nav-link::before {
  content: attr(data-nav-index);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .08em;
  color: var(--line);
  transition: color .2s var(--ease);
}

.nav-link:hover {
  color: var(--white);
  background: rgba(47, 227, 210, .08);
  border-color: rgba(47, 227, 210, .40);
}

.nav-link:hover::before { color: var(--cyan); }

.nav-link[aria-current="page"] {
  color: var(--white);
  background: rgba(255, 122, 47, .13);
  border-color: var(--orange);
}

.nav-link[aria-current="page"]::before { color: var(--orange); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* 移动端按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 15px;
  background: rgba(19, 28, 49, .65);
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
}

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  transition: background .2s var(--ease);
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: inherit;
  transition: top .24s var(--ease), transform .24s var(--ease);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { top: 0; transform: rotate(-45deg); }

.nav-toggle-label {
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--white);
}

/* 滚动后压缩态：品牌区块保留 */
.site-header[data-condensed] .header-shell { padding-block: 10px; }
.site-header[data-condensed] .brand-mark { width: 30px; height: 30px; }
.site-header[data-condensed] .nav-link { padding: 6px 11px; font-size: 13.5px; }
.site-header[data-condensed] .nav-actions .btn-ghost { display: none; }

/* --- 7. 联赛悬浮标签 --- */
.league-dock {
  position: fixed;
  z-index: 80;
  right: 24px;
  bottom: 24px;
  display: flex;
  align-items: center;
  gap: 14px;
  max-width: min(720px, calc(100vw - 48px));
  padding: 10px 16px;
  background: rgba(11, 18, 32, .93);
  border: 1px solid var(--line);
  border-radius: 999px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.league-dock-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .10em;
  color: var(--gray);
  white-space: nowrap;
}

.league-dock-tabs {
  display: flex;
  align-items: center;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
}

.league-dock-tabs::-webkit-scrollbar { display: none; }

.league-tab {
  padding: 7px 14px;
  font-size: 13px;
  white-space: nowrap;
  color: var(--gray);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.league-tab:hover {
  color: var(--white);
  border-color: rgba(47, 227, 210, .45);
}

.league-tab[aria-pressed="true"] {
  color: var(--cyan);
  border-color: var(--orange);
  background: rgba(255, 122, 47, .12);
}

.league-tab[aria-pressed="true"]::before {
  content: "◆ ";
  font-size: 10px;
  color: var(--orange);
}

.league-tab[data-disabled="true"],
.league-tab:disabled {
  opacity: .32;
  cursor: not-allowed;
  border-style: dashed;
}

.league-tab[data-disabled="true"]:hover,
.league-tab:disabled:hover {
  color: var(--gray);
  border-color: var(--line);
}

.league-dock-note {
  font-size: 11px;
  color: var(--gray);
  white-space: nowrap;
}

/* --- 8. 通用按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  text-decoration: none;
  color: var(--white);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease), transform .2s var(--ease);
}

.btn:hover { transform: translateY(-1px); }

.btn-primary {
  color: #180800;
  background: linear-gradient(120deg, var(--orange), var(--orange-soft));
  border-color: transparent;
}

.btn-primary:hover { filter: brightness(1.07); }

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

.btn-ghost:hover {
  color: var(--cyan-soft);
  border-color: rgba(47, 227, 210, .55);
  background: rgba(47, 227, 210, .07);
}

.btn-quiet {
  padding: 8px 16px;
  font-size: 13px;
  background: rgba(19, 28, 49, .75);
}

.btn-quiet:hover {
  border-color: var(--orange);
  color: var(--orange-soft);
}

/* --- 9. 页脚 --- */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: 96px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(11, 18, 32, .78), #05070F 62%);
}

.site-footer::before {
  content: "";
  position: absolute;
  left: -8%;
  top: -34px;
  width: 116%;
  height: 68px;
  background: linear-gradient(90deg, rgba(47, 227, 210, .06), rgba(255, 122, 47, .12));
  transform: skewY(-1.4deg);
  pointer-events: none;
}

.footer-sky {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(620px 260px at 12% -6%, rgba(255, 122, 47, .15), transparent 62%),
    radial-gradient(540px 240px at 84% 6%, rgba(47, 227, 210, .12), transparent 64%);
}

.footer-shell {
  position: relative;
  padding-block: 64px 32px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) 2fr;
  gap: 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}

.footer-brand-line {
  font-size: 19px;
  font-weight: 850;
  letter-spacing: -.01em;
  color: var(--white);
}

.footer-hours {
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: var(--cyan-soft);
}

.feedback-panel {
  display: block;
  width: 100%;
  padding: 16px 18px;
  background: rgba(19, 28, 49, .85);
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  border-radius: 4px 18px 18px 4px;
}

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

.feedback-title {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--gray);
  margin-bottom: 6px;
}

.feedback-line {
  font-family: var(--mono);
  font-size: 14px;
  color: var(--cyan);
  word-break: break-all;
}

.feedback-note {
  margin-top: 6px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--gray);
}

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

.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--gray);
}

.footer-list {
  display: grid;
  gap: 10px;
}

.footer-link {
  display: inline-block;
  padding-bottom: 2px;
  font-size: 14.5px;
  color: rgba(244, 247, 255, .84);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

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

.footer-bottom {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.footer-contact {
  display: grid;
  gap: 6px;
  max-width: 62ch;
}

.footer-contact-line {
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--white);
  word-break: break-word;
}

.footer-address {
  font-size: 13px;
  color: var(--gray);
}

.footer-note {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--gray);
}

.footer-meta {
  display: grid;
  gap: 4px;
  justify-items: end;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--gray);
}

.footer-icp { color: var(--gray); }
.footer-copy { color: rgba(147, 161, 191, .8); }

/* --- 10. 通用内容组件 --- */
.band {
  position: relative;
  padding-block: 72px;
}

.band--deep {
  background: var(--deep);
  border-block: 1px solid var(--line);
}

.band--panel {
  background: linear-gradient(180deg, rgba(19, 28, 49, .78), rgba(5, 7, 15, 0));
}

.band-head {
  display: flex;
  align-items: flex-end;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.band-index {
  font-family: var(--mono);
  font-size: clamp(40px, 6vw, 56px);
  line-height: 1;
  color: rgba(34, 48, 76, .95);
  -webkit-text-stroke: 1px var(--line);
}

.eyebrow {
  margin-bottom: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  margin-bottom: 12px;
}

.lede {
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--gray);
}

.data-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -.01em;
  color: var(--cyan);
}

.divider {
  height: 1px;
  border: 0;
  margin: 32px 0;
  background: linear-gradient(90deg, var(--line), rgba(34, 48, 76, 0));
}

.card {
  padding: 24px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.card:hover {
  border-color: rgba(47, 227, 210, .42);
  background: #16203a;
}

.card-title {
  font-size: 19px;
  margin-bottom: 8px;
}

.card-meta {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--gray);
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .04em;
  color: var(--gray);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.pill--orange {
  color: var(--orange-soft);
  border-color: rgba(255, 122, 47, .52);
}

.pill--cyan {
  color: var(--cyan);
  border-color: rgba(47, 227, 210, .48);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-value {
  font-family: var(--mono);
  font-size: clamp(24px, 3vw, 28px);
  line-height: 1.2;
  color: var(--white);
}

.stat-label {
  font-size: 12px;
  color: var(--gray);
}

/* 专题研究板 */
.study-board {
  background: linear-gradient(160deg, rgba(19, 28, 49, .94), rgba(11, 18, 32, .74));
  border: 1px solid var(--line);
  border-radius: var(--radius-soft);
  overflow: hidden;
}

.study-board__head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  padding: 22px 26px;
  border-bottom: 1px solid var(--line);
}

.study-board__body {
  padding: 22px 26px;
}

.board-fold {
  border-top: 1px solid var(--line);
}

.board-fold > summary {
  position: relative;
  padding: 14px 26px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--cyan);
  cursor: pointer;
  list-style: none;
}

.board-fold > summary::-webkit-details-marker { display: none; }

.board-fold > summary::after {
  content: "+";
  position: absolute;
  right: 26px;
  color: var(--gray);
}

.board-fold[open] > summary::after { content: "–"; }

.board-fold > *:not(summary) {
  padding-inline: 26px;
}

/* 图片容器（页面阶段放图） */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: linear-gradient(140deg, var(--deep), var(--panel));
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(160deg, rgba(47, 227, 210, .12), transparent 46%, rgba(255, 122, 47, .16));
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--portrait { aspect-ratio: 3 / 4; }

/* 面包屑与正文 */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--gray);
}

.breadcrumb a {
  color: var(--gray);
  text-decoration: none;
}

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

.page-head {
  padding-block: 44px 26px;
  border-bottom: 1px solid var(--line);
}

.prose {
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.75;
  color: #D9E1F3;
}

.prose p { margin-bottom: 1.1em; }
.prose p:last-child { margin-bottom: 0; }

/* 动效与筛选状态 */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .24s var(--ease), transform .24s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

[data-league] {
  transition: opacity .16s var(--ease);
}

.is-fading { opacity: 0; }

.is-hidden { display: none !important; }

/* --- 11. 响应式 --- */
@media (max-width: 1024px) {
  .header-shell { grid-template-columns: minmax(180px, 230px) minmax(0, 1fr); gap: 24px; }
  .footer-top { grid-template-columns: 1fr; gap: 36px; }
}

@media (max-width: 960px) {
  .header-shell {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 16px;
    padding-block: 14px;
  }

  .brand-rail {
    padding-right: 0;
    border-right: 0;
  }

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

  .site-nav {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 14px;
    max-height: 0;
    padding-block: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    border-top: 1px solid transparent;
    transition: max-height .32s var(--ease), opacity .2s var(--ease), padding .3s var(--ease);
  }

  .site-nav[data-open] {
    max-height: 78vh;
    padding-block: 16px;
    overflow-y: auto;
    opacity: 1;
    visibility: visible;
    border-top-color: var(--line);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
  }

  .nav-link {
    justify-content: flex-start;
    padding: 12px 14px;
    font-size: 16px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: rgba(19, 28, 49, .5);
  }

  .nav-actions {
    padding-top: 4px;
  }

  .nav-actions .btn { flex: 1 1 auto; }

  .grid-12 { gap: 20px; }
  .col-3, .col-4, .col-6 { grid-column: span 6; }
  .col-8 { grid-column: span 12; }
}

@media (max-width: 768px) {
  :root { --gutter: 16px; }

  body { padding-bottom: 108px; }

  .band { padding-block: 52px; }

  .col-3, .col-4, .col-6, .col-8, .col-9 { grid-column: span 12; }

  .league-dock {
    left: 12px;
    right: 12px;
    bottom: 12px;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    max-width: none;
    padding: 10px 12px;
    border-radius: 18px;
  }

  .league-dock-tabs { width: 100%; }

  .league-dock-note { display: none; }

  .footer-cols { grid-template-columns: 1fr 1fr; gap: 24px; }

  .footer-bottom { flex-direction: column; }

  .footer-meta { justify-items: start; }

  .site-footer { margin-top: 72px; }
}

@media (max-width: 480px) {
  .brand-name { font-size: 16px; }
  .brand-tagline { letter-spacing: .06em; }
  .footer-cols { grid-template-columns: 1fr; }
  .study-board__head, .study-board__body { padding-inline: 18px; }
  .board-fold > summary { padding-inline: 18px; }
  .board-fold > *:not(summary) { padding-inline: 18px; }
}

/* --- 12. 降低动效 --- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }

  .btn:hover { transform: none; }
}