/* ==========================================================================
   亚星体育 · 共享样式表  /assets/site.css
   高原夜空底 + 珠宝色分区 + 粗野主义信息块
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  background-color: #0A1730;
  scroll-behavior: smooth;
}

body, h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd, pre { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; color: inherit; margin: 0; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 变量 ---------- */
:root {
  --sky: #0A1730;
  --mid: #102A4C;
  --card: #163A63;
  --line: #24497A;
  --gold: #E7B23E;
  --gold-soft: #F6D488;
  --snow: #F2EEE4;
  --red: #C8382C;
  --green: #3F8F5C;
  --mist: #8CA0C4;
  --violet: #6A4CA6;
  --void: #050C1A;

  --font-display: "WordBreaker Heavy", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-data: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --maxw: 1360px;
  --gutter: 24px;
  --shadow-hard: 6px 6px 0 var(--void);
  --shadow-hard-sm: 4px 4px 0 var(--void);
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  color: var(--snow);
  background-color: var(--sky);
  background-image:
    radial-gradient(1200px 700px at 8% -6%, rgba(36, 73, 122, .60), transparent 65%),
    radial-gradient(1000px 620px at 102% 3%, rgba(106, 76, 166, .20), transparent 66%);
  background-repeat: no-repeat;
  background-size: 100% 1400px, 100% 1200px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (max-width: 640px) {
  body { font-size: 16px; }
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.2;
  color: var(--snow);
}

::selection { background: var(--gold); color: var(--sky); }

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

#main-content:focus { outline: none; }

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 200;
  padding: 12px 20px;
  background: var(--gold);
  color: var(--sky);
  font-weight: 700;
  font-size: 14px;
  border: 2px solid var(--sky);
  box-shadow: var(--shadow-hard-sm);
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 12px; }

/* ---------- 5. 容器与栅格 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid { display: grid; gap: 32px; }
.grid--62-38 { grid-template-columns: minmax(0, 62fr) minmax(0, 38fr); }
.grid--70-30 { grid-template-columns: minmax(0, 70fr) minmax(0, 30fr); }
.grid--38-62 { grid-template-columns: minmax(0, 38fr) minmax(0, 62fr); }
.grid--halves { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--thirds { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

@media (max-width: 1024px) {
  .grid--62-38,
  .grid--70-30,
  .grid--38-62,
  .grid--thirds { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 720px) {
  .grid { gap: 24px; }
  .grid--halves { grid-template-columns: minmax(0, 1fr); }
  .grid--auto { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 6. 章节节奏 ---------- */
.section { padding: 96px 0; }
.section--tight { padding: 64px 0; }
.section--wide { padding: 128px 0; }

@media (max-width: 720px) {
  .section { padding: 64px 0; }
  .section--tight { padding: 44px 0; }
  .section--wide { padding: 80px 0; }
}

.section-head {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 56ch;
  margin-bottom: 40px;
}

.eyebrow {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .20em;
  text-transform: uppercase;
  color: var(--gold);
}

.section-title {
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1.18;
}

.section-title--xl { font-size: clamp(30px, 5.6vw, 52px); }

.section-lead {
  font-size: 17px;
  line-height: 1.75;
  color: var(--mist);
  max-width: 46ch;
}

/* ---------- 7. 展览标签 ---------- */
.plate {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 12px;
  background: var(--card);
  border: 2px solid var(--line);
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
  align-self: flex-start;
}

.plate::before {
  content: "";
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  background: var(--gold);
}

.plate-note {
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  max-width: 48ch;
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 26px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform .16s var(--ease), box-shadow .16s var(--ease),
              background-color .16s var(--ease), color .16s var(--ease),
              border-color .16s var(--ease);
}

.btn--gold {
  background: var(--gold);
  color: var(--sky);
  box-shadow: 4px 4px 0 var(--red);
}
.btn--gold:hover { background: var(--gold-soft); transform: translate(-2px, -2px); box-shadow: 6px 6px 0 var(--red); }

.btn--outline {
  background: transparent;
  color: var(--snow);
  border-color: var(--line);
  box-shadow: 4px 4px 0 var(--void);
}
.btn--outline:hover { border-color: var(--gold); color: var(--gold); transform: translate(-2px, -2px); }

.btn:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--void); }

/* ---------- 9. 面包屑 ---------- */
.breadcrumb { padding-top: 22px; }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.breadcrumb-link { color: var(--mist); }
.breadcrumb-link:hover { color: var(--gold); }
.breadcrumb-item[aria-current="page"] { color: var(--snow); }

/* ---------- 10. 长文容器 ---------- */
.prose {
  max-width: 34em;
  font-size: 17px;
  line-height: 1.75;
  color: var(--snow);
}

.prose p + p { margin-top: 1.15em; }

.prose h2 {
  font-size: clamp(22px, 2.6vw, 28px);
  margin: 1.8em 0 .6em;
}
.prose h3 {
  font-size: clamp(18px, 2vw, 22px);
  margin: 1.5em 0 .5em;
}

.prose ul {
  display: flex;
  flex-direction: column;
  gap: .55em;
  margin: 1em 0;
}

.prose ul li { position: relative; padding-left: 1.5em; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 9px;
  height: 2px;
  background: var(--gold);
}

.prose a {
  color: var(--gold);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.prose a:hover { color: var(--gold-soft); }

/* ---------- 11. 数据卡 / 统计 / 标签 ---------- */
.data-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 20px 22px;
  background: var(--card);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-hard-sm);
}

.data-card-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.data-card-title { font-size: 16px; font-weight: 700; color: var(--snow); }

.data-card-meta {
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--mist);
  white-space: nowrap;
}

.data-card-body { display: flex; flex-direction: column; gap: 10px; }

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

.stat-value {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(26px, 3vw, 34px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--gold);
}

.stat-label { font-size: 13px; color: var(--mist); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.6;
  background: var(--line);
  color: var(--snow);
  white-space: nowrap;
}

.tag--out { background: var(--red); color: var(--snow); }
.tag--back { background: var(--green); color: var(--snow); }
.tag--move { background: var(--violet); color: var(--snow); }
.tag--gold { background: var(--gold); color: var(--sky); }

/* ---------- 12. 图片容器（页面阶段放占位） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(150deg, var(--mid) 0%, var(--sky) 55%, var(--card) 100%);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-hard-sm);
}

.media-frame-inner {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  display: grid;
  place-items: center;
  overflow: hidden;
}

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

.media-frame--wide .media-frame-inner { aspect-ratio: 21 / 9; }
.media-frame--tall .media-frame-inner { aspect-ratio: 4 / 5; }
.media-frame--square .media-frame-inner { aspect-ratio: 1 / 1; }

.media-frame-caption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  background: rgba(10, 23, 48, .72);
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

.media-frame-placeholder {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: rgba(140, 160, 196, .55);
}

/* ---------- 13. 章节索引 ---------- */
.chapter-rail {
  position: sticky;
  top: 96px;
  align-self: start;
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 18px 0;
  border-left: 2px solid var(--line);
}

.chapter-rail-title {
  padding: 0 0 12px 18px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
}

.chapter-rail-link {
  display: block;
  margin-left: -2px;
  padding: 8px 0 8px 18px;
  border-left: 2px solid transparent;
  font-size: 14px;
  line-height: 1.5;
  color: var(--mist);
  transition: color .20s var(--ease), border-color .20s var(--ease),
              background-color .20s var(--ease);
}

.chapter-rail-link:hover { color: var(--snow); background: rgba(36, 73, 122, .28); }
.chapter-rail-link.is-active { color: var(--gold); border-left-color: var(--gold); }

@media (max-width: 1024px) {
  .chapter-rail { position: static; top: auto; }
}

/* ---------- 14. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--sky);
  border-bottom: 2px solid var(--line);
}

.header-inner {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 14px var(--gutter);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  column-gap: 32px;
  row-gap: 10px;
  min-height: 72px;
}

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

.brand-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  background: var(--gold);
  color: var(--sky);
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  line-height: 1;
  box-shadow: 3px 3px 0 var(--red);
  transition: width .2s var(--ease), height .2s var(--ease), font-size .2s var(--ease);
}

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

.brand-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.1;
  color: var(--snow);
  transition: font-size .2s var(--ease);
}

.brand-tagline {
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: .06em;
  color: var(--mist);
  white-space: nowrap;
}

/* 移动按钮 */
.nav-toggle {
  display: none;
  justify-self: end;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  background: var(--card);
  border: 2px solid var(--line);
  color: var(--snow);
  font-size: 13px;
  font-weight: 700;
  transition: border-color .16s var(--ease), color .16s var(--ease);
}
.nav-toggle:hover { border-color: var(--gold); color: var(--gold); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--gold);
  transition: background-color .2s var(--ease);
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--gold);
  transition: transform .2s 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 { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-6px) rotate(-45deg); }

.nav-toggle-label { letter-spacing: .08em; }

/* 导航 */
.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 26px;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  min-width: 0;
}

.nav-list--secondary {
  padding-left: 22px;
  border-left: 2px solid var(--line);
}

.nav-item { min-width: 0; }

.nav-link {
  display: block;
  padding: 8px 12px;
  border-bottom: 2px solid transparent;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--mist);
  white-space: nowrap;
  transition: color .18s var(--ease), border-color .18s var(--ease),
              background-color .18s var(--ease);
}

.nav-link:hover {
  color: var(--snow);
  background: rgba(36, 73, 122, .38);
}

.nav-link[aria-current="page"] {
  color: var(--gold);
  border-bottom-color: var(--gold);
  background: rgba(231, 178, 62, .08);
}

/* 快捷入口 */
.header-tools {
  display: flex;
  align-items: center;
  gap: 10px;
}

.tool-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  background: var(--card);
  border: 2px solid var(--line);
  color: var(--snow);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.3;
  white-space: nowrap;
  box-shadow: 3px 3px 0 var(--void);
  transition: transform .16s var(--ease), box-shadow .16s var(--ease),
              background-color .16s var(--ease), border-color .16s var(--ease);
}
.tool-link:hover {
  background: var(--mid);
  border-color: var(--gold);
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--void);
}
.tool-link:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--void); }

.tool-link-text { letter-spacing: .04em; }

.tool-count {
  display: inline-block;
  min-width: 20px;
  padding: 3px 5px;
  background: var(--gold);
  color: var(--sky);
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 700;
  line-height: 1;
  text-align: center;
  border-radius: 999px;
}

/* 滚动折叠态 */
.site-header.is-condensed .header-inner { min-height: 56px; padding-top: 6px; padding-bottom: 6px; }
.site-header.is-condensed .brand-tagline { display: none; }
.site-header.is-condensed .brand-mark { width: 32px; height: 32px; font-size: 18px; box-shadow: 2px 2px 0 var(--red); }
.site-header.is-condensed .brand-name { font-size: 18px; }
.site-header.is-condensed .nav-link { padding-top: 6px; padding-bottom: 6px; }

/* 头部响应式 */
@media (max-width: 1080px) {
  .header-inner { grid-template-columns: minmax(0, 1fr) auto; column-gap: 16px; }
  .brand { grid-column: 1; grid-row: 1; }
  .nav-toggle { grid-column: 2; grid-row: 1; display: inline-flex; }
  .header-tools { grid-column: 1 / -1; grid-row: 3; flex-wrap: wrap; }
  .site-nav {
    grid-column: 1 / -1;
    grid-row: 2;
    display: none;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    margin-top: 4px;
    padding-top: 10px;
    border-top: 2px solid var(--line);
    overflow: visible;
  }
  .site-nav[data-open="true"] { display: flex; }
  .nav-list { flex-direction: column; align-items: stretch; gap: 0; }
  .nav-list--secondary {
    margin-top: 8px;
    padding-left: 0;
    padding-top: 8px;
    border-left: 0;
    border-top: 1px solid var(--line);
  }
  .nav-link { padding: 12px 6px; font-size: 15px; }

  .site-header.is-condensed .header-inner { min-height: 56px; }
}

@media (max-width: 480px) {
  :root { --gutter: 16px; }
  .header-inner { padding-top: 10px; padding-bottom: 10px; }
  .brand-name { font-size: 19px; }
  .brand-tagline { font-size: 11px; }
  .tool-link { padding: 8px 11px; font-size: 12px; }
}

/* ---------- 15. 页脚 ---------- */
.site-footer {
  margin-top: 96px;
  background: linear-gradient(180deg, var(--mid) 0%, var(--sky) 62%);
  border-top: 2px solid var(--line);
  color: var(--snow);
}

.footer-inner {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 64px var(--gutter) 32px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1.6fr);
  gap: 48px 64px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 34ch;
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--snow);
}

.footer-brand-line {
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.footer-stripe {
  display: flex;
  gap: 6px;
  height: 6px;
  width: 132px;
}
.footer-stripe span { flex: 1; display: block; }
.footer-stripe span:nth-child(1) { background: var(--gold); }
.footer-stripe span:nth-child(2) { background: var(--red); }
.footer-stripe span:nth-child(3) { background: var(--green); }
.footer-stripe span:nth-child(4) { background: var(--violet); }

.footer-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
}

.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--font-data);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
}

.footer-list { display: flex; flex-direction: column; gap: 2px; }

.footer-link {
  display: inline-block;
  padding: 6px 0;
  border-bottom: 1px solid transparent;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(242, 238, 228, .84);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.footer-link:hover { color: var(--gold); border-bottom-color: var(--gold); }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 20px 32px;
  margin-top: 48px;
  padding-top: 28px;
  border-top: 2px solid var(--line);
}

.footer-contact-item { display: flex; flex-direction: column; gap: 5px; }

.footer-contact-label {
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mist);
}

.footer-contact-value {
  font-size: 15px;
  line-height: 1.65;
  color: var(--snow);
  word-break: break-word;
}

.footer-contact-value--data {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  letter-spacing: .01em;
}

.footer-note {
  margin-top: 28px;
  padding: 14px 18px;
  border-left: 4px solid var(--violet);
  background: rgba(106, 76, 166, .14);
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  margin-top: 36px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

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

.footer-legal-link {
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
  transition: color .18s var(--ease);
}
.footer-legal-link:hover { color: var(--gold); }

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 20px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--mist);
}

.footer-icp { white-space: nowrap; }
.footer-copy { white-space: nowrap; }

@media (max-width: 1024px) {
  .footer-top { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 640px) {
  .site-footer { margin-top: 64px; }
  .footer-inner { padding: 48px var(--gutter) 28px; }
  .footer-columns { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
  .footer-brand-name { font-size: 25px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 400px) {
  .footer-columns { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 16. 滚动进度条与返回首屏 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 120;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--gold) 0%, var(--red) 55%, var(--violet) 100%);
  pointer-events: none;
}

.to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 16px;
  background: var(--gold);
  color: var(--sky);
  border: 2px solid var(--sky);
  box-shadow: 4px 4px 0 var(--red);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.2;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .24s var(--ease), transform .24s var(--ease),
              visibility .24s var(--ease), background-color .16s var(--ease);
}

.to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--gold-soft); }
.to-top:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--red); }

.to-top-arrow { font-family: var(--font-data); font-size: 14px; line-height: 1; }

@media (max-width: 640px) {
  .to-top { right: 16px; bottom: 16px; padding: 10px 13px; font-size: 12px; }
}

/* ---------- 17. 入场显现 ---------- */
html.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
}

html.has-js [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity .24s var(--ease), transform .24s var(--ease);
}

/* ---------- 18. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

  html.has-js [data-reveal],
  html.has-js [data-reveal].is-visible {
    opacity: 1;
    transform: none;
  }
}