/* ============================================================
   环亚赛事 · 共享基础样式 /assets/site.css
   城市看台长卷：深蓝底 + 看台橙强调 + 玻璃层 + 等宽数据
   ============================================================ */

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

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

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

ul, ol { list-style: none; }

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

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

a { color: inherit; }

/* ---------- 2. 变量 ---------- */
:root {
  --blue-deep: #0B2540;
  --orange: #FF6A1A;
  --blue-night: #121A26;
  --blue-sky: #1E5A8A;
  --green: #34C77B;
  --glass: #7FD3E8;
  --amber: #FFB547;
  --rose: #E2486B;
  --silver: #C7D0DA;
  --mist: #F4F7FA;
  --ink: #0B2540;

  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-display: var(--font-body);
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;

  --shell: 1440px;
  --gut: 24px;
  --pad: clamp(20px, 5vw, 8vw);
  --header-h: 72px;
  --cut: 7deg;
  --radius: 12px;
  --radius-s: 8px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--blue-deep);
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .01em;
  min-height: 100%;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 250;
  line-height: 1.08;
  letter-spacing: -.01em;
}

strong { font-weight: 700; }

::selection { background: var(--orange); color: #08192B; }

#main-content { scroll-margin-top: calc(var(--header-h) + 24px); }

:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 4. 布局工具 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.section { padding-block: clamp(56px, 8vw, 112px); position: relative; }
.section--deep { background: var(--blue-deep); }
.section--night { background: var(--blue-night); }
.section--sky { background: var(--blue-sky); }
.section--mist { background: var(--mist); color: var(--ink); }

.section--mist .chapter__lede,
.section--mist .stat__label,
.section--mist .prose { color: #41586F; }
.section--mist .card {
  background: rgba(30, 90, 138, .06);
  border-color: rgba(30, 90, 138, .18);
}
.section--mist .card:hover {
  background: rgba(30, 90, 138, .12);
  border-color: rgba(30, 90, 138, .3);
}
.section--mist .stat__value { color: var(--blue-deep); }

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

.grid > [class*="col-"] { grid-column: 1 / -1; }

@media (min-width: 901px) {
  .col-3 { grid-column: span 3; }
  .col-4 { grid-column: span 4; }
  .col-5 { grid-column: span 5; }
  .col-6 { grid-column: span 6; }
  .col-7 { grid-column: span 7; }
  .col-8 { grid-column: span 8; }
  .col-9 { grid-column: span 9; }
  .col-10 { grid-column: span 10; }
  .col-12 { grid-column: span 12; }
  .start-5 { grid-column-start: 5; }
  .start-6 { grid-column-start: 6; }
  .start-7 { grid-column-start: 7; }
  .start-8 { grid-column-start: 8; }
}

/* 章节之间的斜向看台色带 */
.band {
  height: clamp(18px, 3.5vw, 40px);
  background: repeating-linear-gradient(
    115deg,
    rgba(255, 106, 26, .88) 0 14px,
    rgba(255, 181, 71, .88) 14px 28px,
    rgba(127, 211, 232, .35) 28px 42px,
    rgba(127, 211, 232, 0) 42px 68px
  );
  opacity: .9;
}

/* ---------- 5. 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 200;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 18px;
  background: var(--amber);
  color: #08192B;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border-radius: 0 0 var(--radius-s) var(--radius-s);
  transition: top .16s var(--ease);
}
.skip-link:focus { top: 0; }

/* ---------- 6. 头部命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: linear-gradient(180deg, rgba(11, 37, 64, .97), rgba(11, 37, 64, .84));
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(127, 211, 232, .18);
  transition: box-shadow .2s var(--ease);
}
.site-header[data-scrolled] { box-shadow: 0 14px 34px rgba(0, 0, 0, .38); }

.cmd-bar {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--pad);
  min-height: var(--header-h);
  transition: min-height .2s var(--ease);
}
.site-header[data-scrolled] .cmd-bar { min-height: 56px; }

.cmd-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--mist);
}

.cmd-brand__mark {
  width: 26px;
  height: 26px;
  flex: 0 0 auto;
  background: var(--orange);
  clip-path: polygon(0 0, 100% 0, 100% 66%, 66% 100%, 0 100%);
  box-shadow: inset 0 0 0 1px rgba(8, 25, 43, .25);
}

.cmd-brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.cmd-brand__name {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .06em;
}
.cmd-brand__tag {
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .08em;
  color: var(--silver);
}

.cmd-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  min-height: 44px;
  min-width: 44px;
  padding: 0 14px;
  background: rgba(127, 211, 232, .12);
  border: 1px solid rgba(127, 211, 232, .3);
  border-radius: var(--radius-s);
  color: var(--mist);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .08em;
  cursor: pointer;
}
.cmd-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 12px;
  flex: 0 0 auto;
}
.cmd-toggle__bars i {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .16s var(--ease), opacity .16s var(--ease);
}
.cmd-toggle__bars i:nth-child(1) { top: 0; }
.cmd-toggle__bars i:nth-child(2) { top: 5px; }
.cmd-toggle__bars i:nth-child(3) { top: 10px; }
.cmd-toggle[aria-expanded="true"] .cmd-toggle__bars i:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.cmd-toggle[aria-expanded="true"] .cmd-toggle__bars i:nth-child(2) { opacity: 0; }
.cmd-toggle[aria-expanded="true"] .cmd-toggle__bars i:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

.cmd-nav {
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.6vw, 26px);
  margin-left: auto;
}

.cmd-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(2px, .8vw, 12px);
}

.cmd-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 10px;
  min-height: 40px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .02em;
  text-decoration: none;
  color: rgba(244, 247, 250, .78);
  border-radius: 6px;
  transition: color .16s var(--ease), background-color .16s var(--ease);
}
.cmd-nav__link:hover,
.cmd-nav__link:focus-visible {
  color: #fff;
  background: rgba(127, 211, 232, .14);
}
.cmd-nav__link[aria-current="page"] { color: #fff; }
.cmd-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 2px;
  height: 2px;
  background: var(--orange);
  border-radius: 2px;
}

.cmd-nav__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--orange);
}

.cmd-nav__meta {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.4vw, 20px);
  padding-left: clamp(10px, 1.4vw, 20px);
  border-left: 1px solid rgba(199, 208, 218, .18);
}

.cmd-status { display: flex; align-items: center; gap: 14px; }
.cmd-status__item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--silver);
  white-space: nowrap;
}
.cmd-status__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  animation: hya-breathe 2s ease-in-out infinite;
}
.cmd-status__item[data-state="sync"] .cmd-status__dot { background: var(--glass); animation-delay: .35s; }
.cmd-status__item[data-state="online"] .cmd-status__dot { background: var(--amber); animation-delay: .7s; }

@keyframes hya-breathe {
  0%, 100% { opacity: 1; }
  50% { opacity: .72; }
}

.cmd-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 18px;
  background: var(--orange);
  color: #08192B;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .03em;
  text-decoration: none;
  border-radius: var(--radius-s);
  border: 1px solid rgba(8, 25, 43, .15);
  white-space: nowrap;
  transition: background-color .16s var(--ease), color .16s var(--ease);
}
.cmd-cta:hover { background: var(--amber); }

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--orange), var(--amber) 60%, var(--glass));
}

/* ---------- 7. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--blue-night);
  border-top: 1px solid rgba(127, 211, 232, .16);
  color: var(--mist);
}
.site-footer::before {
  content: "";
  display: block;
  height: 5px;
  background: repeating-linear-gradient(
    90deg,
    var(--orange) 0 28px,
    rgba(255, 106, 26, 0) 28px 44px,
    var(--glass) 44px 56px,
    rgba(127, 211, 232, 0) 56px 72px
  );
  opacity: .6;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1fr 1.5fr;
  gap: clamp(24px, 3vw, 44px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 72px) var(--pad) clamp(28px, 4vw, 48px);
}

.footer-brand { display: flex; flex-direction: column; gap: 8px; }
.footer-brand__mark {
  width: 30px;
  height: 30px;
  background: var(--orange);
  clip-path: polygon(0 0, 100% 0, 100% 66%, 66% 100%, 0 100%);
  margin-bottom: 6px;
}
.footer-brand__name {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .06em;
}
.footer-brand__tag {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--glass);
}
.footer-brand__summary {
  margin-top: 8px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--silver);
}

.footer-col { display: flex; flex-direction: column; gap: 14px; }
.footer-col__title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--orange);
  text-transform: uppercase;
}
.footer-col__list { display: flex; flex-direction: column; gap: 4px; }

.footer-link {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  font-size: 15px;
  color: rgba(244, 247, 250, .82);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.footer-link:hover,
.footer-link:focus-visible {
  color: #fff;
  border-bottom-color: var(--orange);
}

.footer-col--contact { gap: 16px; }
.footer-meta { display: grid; gap: 4px 10px; grid-template-columns: auto 1fr; }
.footer-meta__key {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--silver);
  padding-top: 3px;
}
.footer-meta__val {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(244, 247, 250, .9);
  overflow-wrap: anywhere;
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 18px var(--pad) 26px;
  border-top: 1px solid rgba(199, 208, 218, .14);
  font-size: 13px;
  color: var(--silver);
}
.footer-base__copy { font-family: var(--font-mono); letter-spacing: .04em; }
.footer-base__icp { letter-spacing: .06em; }

/* ---------- 8. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-s);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .02em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}
.btn--primary { background: var(--orange); color: #08192B; }
.btn--primary:hover { background: var(--amber); }
.btn--ghost {
  background: rgba(127, 211, 232, .12);
  border-color: rgba(127, 211, 232, .34);
  color: var(--mist);
}
.btn--ghost:hover { background: rgba(127, 211, 232, .2); }
.btn--quiet {
  background: transparent;
  border-color: rgba(199, 208, 218, .32);
  color: var(--silver);
}
.btn--quiet:hover { border-color: var(--silver); color: var(--mist); }
.section--mist .btn--ghost,
.section--mist .btn--quiet { color: var(--blue-deep); border-color: rgba(30, 90, 138, .34); }

/* ---------- 9. 面包屑 ---------- */
.breadcrumb { font-size: 13px; color: var(--silver); }
.section--mist .breadcrumb { color: #53708C; }
.breadcrumb__list { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: rgba(199, 208, 218, .5);
}
.breadcrumb__item a {
  text-decoration: none;
  border-bottom: 1px solid rgba(199, 208, 218, .35);
}
.breadcrumb__item a:hover { border-bottom-color: var(--orange); }

/* ---------- 10. 正文容器 ---------- */
.prose {
  max-width: 72ch;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--silver);
}
.prose > * + * { margin-top: 1.1em; }
.prose h2 {
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 250;
  color: var(--mist);
  margin-top: 1.8em;
}
.prose h3 {
  font-size: clamp(19px, 2vw, 23px);
  font-weight: 400;
  color: var(--mist);
  margin-top: 1.6em;
}
.prose ul { list-style: none; }
.prose ul li {
  position: relative;
  padding-left: 20px;
}
.prose ul li + li { margin-top: .4em; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 8px;
  height: 2px;
  background: var(--orange);
}
.prose a {
  color: var(--glass);
  text-decoration: none;
  border-bottom: 1px solid rgba(127, 211, 232, .45);
}
.prose a:hover { border-bottom-color: var(--amber); }
.section--mist .prose h2,
.section--mist .prose h3 { color: var(--blue-deep); }

/* ---------- 11. 章节 ---------- */
.chapter {
  position: relative;
  padding-block: clamp(44px, 6vw, 88px);
  scroll-margin-top: calc(var(--header-h) + 32px);
}
.chapter__head {
  display: grid;
  gap: 12px;
  padding-left: 18px;
  border-left: 2px solid var(--orange);
  margin-bottom: clamp(22px, 3vw, 40px);
}
.chapter__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--orange);
}
.chapter__title {
  font-size: clamp(30px, 5vw, 64px);
  font-weight: 250;
  line-height: 1.06;
  letter-spacing: -.015em;
}
.chapter__lede {
  max-width: 62ch;
  font-size: clamp(15.5px, 1.3vw, 18px);
  line-height: 1.75;
  color: var(--silver);
}

/* ---------- 12. 玻璃层与卡片 ---------- */
.glass {
  background: rgba(127, 211, 232, .12);
  border: 1px solid rgba(127, 211, 232, .22);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: background-color .16s var(--ease);
}
.glass:hover { background: rgba(127, 211, 232, .2); }

.card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2vw, 26px);
  background: rgba(127, 211, 232, .08);
  border: 1px solid rgba(127, 211, 232, .18);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: background-color .16s var(--ease), border-color .16s var(--ease);
}
.card:hover {
  background: rgba(127, 211, 232, .14);
  border-color: rgba(127, 211, 232, .34);
}
.card__title {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: .01em;
}
.card__text { font-size: 14.5px; line-height: 1.75; color: var(--silver); }
.card__meta {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--glass);
}

/* ---------- 13. 数据与标签 ---------- */
.stat { display: flex; flex-direction: column; gap: 4px; }
.stat__value {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.4vw, 32px);
  font-weight: 500;
  letter-spacing: .04em;
  line-height: 1.2;
  color: var(--mist);
}
.stat__label {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--silver);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--green);
  background: rgba(52, 199, 123, .14);
  border: 1px solid rgba(52, 199, 123, .32);
}

/* ---------- 14. 折叠面板 ---------- */
.accordion { border-top: 1px solid rgba(199, 208, 218, .22); }
.accordion__item { border-bottom: 1px solid rgba(199, 208, 218, .22); }
.accordion__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 56px;
  padding: 14px 4px;
  font-size: 17px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.accordion__summary::-webkit-details-marker { display: none; }
.accordion__summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  color: var(--orange);
  flex: 0 0 auto;
}
.accordion__item[open] .accordion__summary::after { content: "–"; }
.accordion__body {
  max-width: 70ch;
  padding: 0 4px 20px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--silver);
}
.section--mist .accordion,
.section--mist .accordion__item { border-color: rgba(30, 90, 138, .2); }
.section--mist .accordion__body { color: #41586F; }

/* ---------- 15. 图片容器基础规则 ---------- */
.media {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  background: linear-gradient(140deg, var(--blue-sky), var(--blue-night));
  aspect-ratio: 16 / 9;
  isolation: isolate;
}
.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--4x3 { aspect-ratio: 4 / 3; }
.media--16x9 { aspect-ratio: 16 / 9; }
.media--21x9 { aspect-ratio: 21 / 9; }
.media--1x1 { aspect-ratio: 1 / 1; }

.media__ph {
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, rgba(244, 247, 250, .07) 0 1px, transparent 1px 46px),
    repeating-linear-gradient(0deg, rgba(244, 247, 250, .07) 0 1px, transparent 1px 46px),
    repeating-linear-gradient(115deg, rgba(255, 106, 26, .16) 0 10px, transparent 10px 76px);
}
.media__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 12px 14px;
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--mist);
  background: linear-gradient(180deg, rgba(11, 37, 64, 0), rgba(11, 37, 64, .86));
}

/* ---------- 16. 侧边章节目录 ---------- */
.chapter-rail {
  position: fixed;
  left: max(14px, 1.6vw);
  top: 50%;
  transform: translateY(-50%);
  z-index: 60;
  display: none;
  max-width: 190px;
}
.chapter-rail__list { display: flex; flex-direction: column; gap: 2px; }
.chapter-rail__link {
  position: relative;
  display: block;
  width: 100%;
  padding: 6px 8px 6px 14px;
  background: none;
  border: 0;
  border-left: 1px solid rgba(199, 208, 218, .22);
  text-align: left;
  font-size: 12px;
  line-height: 1.5;
  color: rgba(199, 208, 218, .62);
  cursor: pointer;
  transition: color .12s var(--ease);
}
.chapter-rail__link::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--orange);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform .12s var(--ease);
}
.chapter-rail__link:hover { color: var(--mist); }
.chapter-rail__link[aria-current="true"] { color: #fff; }
.chapter-rail__link[aria-current="true"]::before { transform: scaleY(1); }
.chapter-rail__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--orange);
}
.chapter-rail__text { display: block; }

@media (min-width: 1280px) {
  .chapter-rail { display: block; }
}

/* ---------- 17. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(16px, 2.4vw, 30px);
  bottom: clamp(16px, 3vh, 32px);
  z-index: 80;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  padding: 0;
  background: rgba(18, 26, 38, .88);
  border: 1px solid rgba(127, 211, 232, .34);
  border-radius: 50%;
  color: var(--mist);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  transform: translateY(18px);
  pointer-events: none;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: opacity .2s var(--ease), transform .2s var(--ease), background-color .16s var(--ease);
}
.to-top[data-visible] {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}
.to-top:hover { background: var(--orange); color: #08192B; border-color: var(--orange); }

/* ---------- 18. 入场渐显 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .16s var(--ease), transform .16s var(--ease);
}
.reveal[data-inview] {
  opacity: 1;
  transform: none;
}

/* ---------- 19. 移动端命令栏 ---------- */
@media (max-width: 1023px) {
  .cmd-toggle { display: inline-flex; }
  .cmd-brand__tag { display: none; }

  .cmd-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 10px var(--pad) 22px;
    background: rgba(9, 22, 38, .98);
    border-bottom: 1px solid rgba(127, 211, 232, .24);
    box-shadow: 0 24px 48px rgba(0, 0, 0, .45);
  }
  .cmd-nav[data-open] { display: flex; }

  .cmd-nav__list { flex-direction: column; align-items: stretch; gap: 2px; width: 100%; }
  .cmd-nav__link {
    justify-content: flex-start;
    min-height: 48px;
    padding: 12px 14px;
    font-size: 16px;
    border-radius: var(--radius-s);
  }
  .cmd-nav__link[aria-current="page"] { background: rgba(255, 106, 26, .12); }
  .cmd-nav__link[aria-current="page"]::after { left: 14px; right: auto; width: 22px; }

  .cmd-nav__meta {
    flex-direction: column;
    align-items: stretch;
    gap: 14px;
    margin-top: 14px;
    padding: 16px 0 0;
    border-left: 0;
    border-top: 1px solid rgba(199, 208, 218, .18);
  }
  .cmd-status { flex-direction: column; align-items: flex-start; gap: 8px; }
  .cmd-cta { width: 100%; }
}

@media (max-width: 1023px) and (min-width: 641px) {
  .cmd-nav__list { flex-direction: row; flex-wrap: wrap; }
  .cmd-nav__link { min-width: 46%; }
}

/* ---------- 20. 页脚响应式 ---------- */
@media (max-width: 1100px) {
  .footer-grid { grid-template-columns: 1fr 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-brand__summary { max-width: 56ch; }
}

@media (max-width: 640px) {
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-meta { grid-template-columns: 1fr; gap: 2px; }
  .footer-meta__key { padding-top: 10px; }
}

/* ---------- 21. 减少动态效果 ---------- */
@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; }
  .to-top { transform: none; }
  .scroll-progress__bar { transition: none; }
}