/* ============================================================
   启博中心 · QIBO EPN 共享样式表  /assets/site.css
   目录型站点骨架：品牌带 + 常用栏 + 命令栏 + 目录页脚
   ============================================================ */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 176px;
}
body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dt, dd, fieldset { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg, video, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
summary { list-style: none; }
summary::-webkit-details-marker { display: none; }
hr { border: 0; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 色彩 */
  --ink-base: #0E1B3A;
  --ink-2: #17295A;
  --cyan: #35E0D2;
  --amber: #E9A23B;
  --mint: #8FCFB6;
  --clay: #9C4F30;
  --stone: #7C8798;
  --paper: #F4F0E6;
  --ink: #0A1024;
  --line: #C9D4E8;
  --line-soft: rgba(201, 212, 232, .22);
  --line-hair: rgba(201, 212, 232, .12);
  --on-dark: #E7EDF9;
  --on-dark-dim: #C3CDE2;
  --on-paper-dim: #4A5568;

  /* 字体 */
  --font-head: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-num: ui-monospace, "SFMono-Regular", "Menlo", "Consolas", "Liberation Mono", monospace;

  --fs-h1: 44px;
  --fs-h2: 32px;
  --fs-h3: 24px;
  --fs-h4: 18px;
  --fs-note: 13px;
  --fs-micro: 12px;

  /* 尺寸与节奏 */
  --wrap: 1240px;
  --gutter: clamp(16px, 4vw, 40px);
  --r: 3px;
  --dur: .24s;
  --sticky-gap: 168px;
  --shadow-plate: 0 1px 0 rgba(10, 16, 36, .06), 0 14px 34px rgba(10, 16, 36, .3);
  --shadow-panel: 0 16px 40px rgba(10, 16, 36, .45);
}

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--ink-base);
  color: var(--on-dark);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .005em;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}
#main-content { flex: 1 0 auto; display: block; }
#main-content:focus { outline: none; }

h1, .h1, h2, .h2, h3, .h3, h4, .h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -.012em;
  color: var(--paper);
}
h1, .h1 { font-size: clamp(30px, 4.6vw, var(--fs-h1)); }
h2, .h2 { font-size: clamp(24px, 3.4vw, var(--fs-h2)); }
h3, .h3 { font-size: clamp(20px, 2.6vw, var(--fs-h3)); }
h4, .h4 { font-size: var(--fs-h4); letter-spacing: -.005em; }
p { max-width: 68ch; }
p + p { margin-top: .8em; }
strong, b { font-weight: 800; color: #fff; }

.num, code, kbd, samp, .mono {
  font-family: var(--font-num);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -.01em;
}
.num-unit { font-size: .68em; font-weight: 500; color: var(--stone); margin-left: .18em; font-family: var(--font-body); }

.visually-hidden {
  position: absolute; width: 1px; height: 1px; margin: -1px;
  padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---------- 4. 容器与布局工具 ---------- */
.container {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section { padding-block: clamp(40px, 6vw, 76px); }
.section--tight { padding-block: clamp(22px, 3vw, 36px); }
.section--paper { background: var(--paper); color: var(--ink); }
.section--paper h1, .section--paper h2, .section--paper h3, .section--paper h4 { color: var(--ink); }
.section--paper p { color: var(--on-paper-dim); }

.section__head { display: flex; flex-wrap: wrap; gap: 14px 20px; align-items: baseline; padding-bottom: 16px; border-bottom: 1px solid var(--line-hair); margin-bottom: clamp(18px, 2.6vw, 30px); }
.section__no { font-family: var(--font-num); font-size: var(--fs-micro); font-weight: 700; letter-spacing: .16em; color: var(--clay); background: rgba(156, 79, 48, .12); border: 1px solid rgba(156, 79, 48, .35); padding: 3px 8px; border-radius: 2px; }
.section__title { font-family: var(--font-head); font-size: clamp(22px, 3vw, var(--fs-h2)); font-weight: 800; letter-spacing: -.012em; }
.section__lead { font-size: 15px; color: var(--stone); max-width: 56ch; }

.rule { height: 1px; background: var(--line-hair); margin-block: clamp(20px, 3vw, 32px); }
.stack { display: grid; gap: clamp(14px, 2vw, 22px); }
.cluster { display: flex; flex-wrap: wrap; gap: 10px 14px; align-items: center; }

.page-grid { display: grid; gap: clamp(22px, 3vw, 40px); grid-template-columns: minmax(0, 1fr); }
@media (min-width: 960px) {
  .page-grid { grid-template-columns: minmax(200px, 248px) minmax(0, 1fr); align-items: start; }
}
.index-rail { display: grid; gap: 8px; }
@media (min-width: 960px) {
  .index-rail { position: sticky; top: var(--sticky-gap); }
}
.grid-2, .grid-3 { display: grid; gap: clamp(16px, 2.4vw, 26px); grid-template-columns: minmax(0, 1fr); }
@media (min-width: 720px) { .grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (min-width: 860px) { .grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); } }

/* ---------- 5. 面板 / 纸张叠层 ---------- */
.panel {
  background: var(--ink-2);
  border: 1px solid var(--line-soft);
  border-radius: var(--r);
  padding: clamp(18px, 2.6vw, 28px);
  box-shadow: var(--shadow-panel);
}
.plate {
  position: relative;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: clamp(20px, 3vw, 34px);
  box-shadow: var(--shadow-plate);
}
.plate h1, .plate h2, .plate h3, .plate h4 { color: var(--ink); }
.plate p { color: var(--on-paper-dim); }
.plate::after {
  content: ""; position: absolute; inset: 6px 6px auto auto;
  width: 34px; height: 2px; background: var(--clay); opacity: .7;
}

/* ---------- 6. 按钮与标签 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 12px 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r);
  background: var(--ink-2);
  color: var(--on-dark);
  font-size: 15px; font-weight: 700; letter-spacing: .015em;
  transition: background var(--dur) ease, border-color var(--dur) ease, color var(--dur) ease, transform var(--dur) ease;
}
.btn:hover { border-color: var(--cyan); color: var(--cyan); transform: translateY(-1px); }
.btn--primary { background: var(--amber); border-color: var(--amber); color: var(--ink); }
.btn--primary:hover { background: #F2B155; border-color: #F2B155; color: var(--ink); }
.btn--ghost { background: transparent; border-color: var(--cyan); color: var(--cyan); }
.btn--ghost:hover { background: rgba(53, 224, 210, .1); }
.btn--sm { padding: 8px 14px; font-size: 13.5px; }

.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: var(--fs-micro); font-weight: 700; letter-spacing: .08em;
  padding: 3px 9px; border: 1px solid var(--line-soft); border-radius: 2px;
  color: var(--stone);
}
.badge--cyan { color: var(--cyan); border-color: rgba(53, 224, 210, .45); }
.badge--amber { color: var(--amber); border-color: rgba(233, 162, 59, .5); background: rgba(233, 162, 59, .08); }
.badge--clay { color: var(--paper); background: var(--clay); border-color: var(--clay); }

/* ---------- 7. 面包屑 ---------- */
.breadcrumbs { padding-block: 16px 0; font-size: var(--fs-note); color: var(--stone); }
.breadcrumbs__list { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.breadcrumbs__item { display: inline-flex; align-items: center; }
.breadcrumbs__item::after { content: "/"; margin-left: 8px; color: rgba(201, 212, 232, .35); }
.breadcrumbs__item:last-child::after { content: none; }
.breadcrumbs__link { color: var(--stone); transition: color var(--dur) ease; }
.breadcrumbs__link:hover { color: var(--cyan); }
.breadcrumbs__current { color: var(--paper); font-weight: 700; }

/* ---------- 8. 数据表 ---------- */
.table-scroll { overflow-x: auto; border: 1px solid var(--line-soft); border-radius: var(--r); }
.data-table { font-size: 14.5px; min-width: 620px; }
.data-table th, .data-table td { padding: 12px 14px; border-bottom: 1px solid var(--line-hair); text-align: left; vertical-align: top; }
.data-table thead th {
  background: var(--ink-2); color: var(--paper);
  font-size: var(--fs-note); font-weight: 800; letter-spacing: .06em;
  border-bottom: 1px solid var(--line-soft);
}
.data-table tbody tr:hover { background: rgba(53, 224, 210, .06); }
.data-table tbody tr:last-child td { border-bottom: 0; }
.data-table .is-new { background: rgba(143, 207, 182, .12); }
.data-table .is-highlight { color: var(--amber); }

/* ---------- 9. 展开组 ---------- */
.fold {
  background: rgba(23, 41, 90, .62);
  border: 1px solid var(--line-soft);
  border-radius: var(--r);
  transition: border-color var(--dur) ease;
}
.fold + .fold { margin-top: 10px; }
.fold:hover { border-color: rgba(53, 224, 210, .45); }
.fold[open] { border-color: rgba(53, 224, 210, .55); }
.fold__head {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 15px 18px; cursor: pointer; font-weight: 700; color: var(--paper);
}
.fold__no { font-family: var(--font-num); font-size: var(--fs-micro); font-weight: 700; color: var(--clay); background: rgba(156, 79, 48, .14); border: 1px solid rgba(156, 79, 48, .4); border-radius: 2px; padding: 2px 6px; margin-top: 3px; flex: 0 0 auto; }
.fold__summary { display: block; font-weight: 400; font-size: 13.5px; color: var(--stone); margin-top: 2px; }
.fold[open] .fold__head { border-bottom: 1px solid var(--line-hair); }
.fold__body { padding: 16px 18px; font-weight: 400; color: var(--on-dark-dim); }

/* ---------- 10. 图片容器（供页面阶段放置图片） ---------- */
.media-frame {
  position: relative;
  display: block;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  border-radius: var(--r);
  background-color: var(--ink-base);
  background-image:
    linear-gradient(180deg, rgba(23, 41, 90, .92), rgba(14, 27, 58, .92)),
    repeating-linear-gradient(90deg, rgba(201, 212, 232, .13) 0 1px, transparent 1px 40px),
    repeating-linear-gradient(0deg, rgba(201, 212, 232, .13) 0 1px, transparent 1px 40px);
  background-size: auto, 40px 40px, 40px 40px;
}
.media-frame > img { width: 100%; height: 100%; object-fit: cover; }
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--dial {
  aspect-ratio: 1 / 1; border-radius: 50%;
  background-image:
    radial-gradient(circle at 50% 50%, rgba(53, 224, 210, .18) 0 2px, transparent 3px),
    conic-gradient(from 210deg, rgba(53, 224, 210, .35) 0 22%, rgba(233, 162, 59, .35) 22% 44%, rgba(156, 79, 48, .3) 44% 60%, rgba(143, 207, 182, .3) 60% 78%, rgba(53, 224, 210, .35) 78% 100%);
}
.media-frame--paper { background-color: var(--paper); background-image: none; border-color: var(--line); }
.media-caption { display: flex; gap: 8px; margin-top: 10px; font-size: var(--fs-note); color: var(--stone); }

/* ---------- 11. 页头 ---------- */
.skip-link {
  position: absolute; left: var(--gutter); top: -64px; z-index: 200;
  padding: 10px 16px;
  background: var(--cyan); color: var(--ink);
  font-size: 14px; font-weight: 800;
  border-radius: 0 0 var(--r) var(--r);
  transition: top .18s ease;
}
.skip-link:focus { top: 0; }

.site-header { position: relative; z-index: 60; background: var(--ink-base); }

/* 11.1 品牌带 */
.brand-rail {
  background: linear-gradient(90deg, var(--ink-base) 0%, #12224A 58%, var(--ink-base) 100%);
  border-bottom: 1px solid var(--line-hair);
}
.brand-rail__inner { display: flex; align-items: center; justify-content: space-between; gap: 12px 18px; min-height: 46px; padding-block: 7px; }
.brand-rail__brand { display: inline-flex; align-items: center; gap: 10px; font-size: 14.5px; font-weight: 800; letter-spacing: .03em; }
.brand-rail__word { color: var(--paper); transition: color var(--dur) ease; }
.brand-rail__brand:hover .brand-rail__word { color: var(--cyan); }
.brand-rail__sep { color: var(--stone); margin-inline: 6px; font-weight: 400; }
.brand-mark {
  width: 16px; height: 16px; flex: 0 0 auto; border-radius: 50%;
  border: 1px solid rgba(53, 224, 210, .6);
  background-image:
    radial-gradient(circle at 50% 50%, var(--cyan) 0 22%, transparent 26%),
    conic-gradient(from 200deg, rgba(53, 224, 210, .95), rgba(233, 162, 59, .9), rgba(53, 224, 210, .95));
  box-shadow: 0 0 0 3px rgba(53, 224, 210, .08);
}
.brand-rail__meta { display: flex; align-items: center; flex-wrap: wrap; gap: 8px 12px; justify-content: flex-end; }
.batch-tag {
  font-family: var(--font-num); font-size: var(--fs-micro); font-weight: 700; letter-spacing: .02em;
  color: var(--amber);
  background: rgba(233, 162, 59, .08);
  border: 1px solid rgba(233, 162, 59, .4);
  border-radius: 2px; padding: 3px 9px;
}
.lang-tag { font-size: var(--fs-micro); letter-spacing: .12em; color: var(--stone); padding-left: 11px; border-left: 1px solid var(--line-soft); }

/* 11.2 吸顶区（常用栏 + 命令栏） */
.site-header__sticky {
  position: sticky; top: 0; z-index: 60;
  background: rgba(14, 27, 58, .97);
  box-shadow: 0 10px 26px rgba(10, 16, 36, .38);
}

.utility-bar { background: linear-gradient(180deg, var(--ink-2), var(--ink-base)); border-bottom: 1px solid var(--line-hair); }
.utility-bar__inner { display: flex; align-items: center; gap: 16px; padding-block: 10px; }
.utility-bar__title {
  flex: 0 0 auto; font-size: var(--fs-micro); font-weight: 800; letter-spacing: .22em;
  color: var(--stone); padding-left: 9px; border-left: 2px solid var(--clay);
}
.utility-bar__list {
  display: flex; flex: 1 1 auto; gap: 10px;
  min-width: 0; padding-bottom: 2px;
  overflow-x: auto; scrollbar-width: thin;
  scroll-snap-type: x proximity;
}
.utility-bar__item { display: flex; }
.util-card {
  display: flex; align-items: center; gap: 12px;
  min-width: 232px; padding: 9px 14px;
  background: rgba(14, 27, 58, .66);
  border: 1px solid var(--line-soft);
  border-radius: var(--r);
  scroll-snap-align: start;
  transition: border-color var(--dur) ease, background var(--dur) ease, transform var(--dur) ease;
}
.util-card:hover { border-color: var(--cyan); background: rgba(53, 224, 210, .07); transform: translateY(-1px); }
.util-card__no {
  flex: 0 0 auto; font-family: var(--font-num); font-size: 11px; font-weight: 700; line-height: 1.5;
  color: var(--ink); background: var(--cyan); border-radius: 2px; padding: 2px 5px;
}
.util-card__body { display: flex; flex-direction: column; min-width: 0; }
.util-card__name { font-size: 14.5px; font-weight: 800; letter-spacing: .02em; color: var(--paper); }
.util-card__hint { font-size: var(--fs-micro); color: var(--stone); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.util-card__go { margin-left: auto; color: var(--cyan); font-size: 15px; transition: transform var(--dur) ease; }
.util-card:hover .util-card__go { transform: translateX(3px); }

.command-bar { position: relative; background: var(--ink-base); border-bottom: 1px solid var(--line-soft); }
.command-bar__inner { position: relative; display: flex; align-items: center; gap: 16px; min-height: 54px; }

.nav-toggle {
  display: none; align-items: center; gap: 10px;
  padding: 9px 14px;
  border: 1px solid var(--line-soft); border-radius: var(--r);
  font-size: 14px; font-weight: 700; color: var(--paper);
  transition: border-color var(--dur) ease, color var(--dur) ease, background var(--dur) ease;
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle__bars { display: inline-flex; flex-direction: column; gap: 3px; width: 16px; }
.nav-toggle__bars span { height: 2px; width: 100%; background: currentColor; border-radius: 1px; transition: opacity var(--dur) ease, width var(--dur) ease, background var(--dur) ease; }
.nav-toggle[aria-expanded="true"] { border-color: var(--amber); color: var(--amber); background: rgba(233, 162, 59, .1); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1),
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { opacity: .3; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { background: var(--amber); }

.site-nav { display: flex; flex: 1 1 auto; align-items: stretch; gap: 2px; min-width: 0; }
.site-nav__item { display: flex; }
.site-nav__link {
  position: relative; display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 12px;
  font-size: 14.5px; font-weight: 700; letter-spacing: .02em;
  color: var(--stone);
  border-bottom: 2px solid transparent;
  transition: color var(--dur) ease, border-color var(--dur) ease, background var(--dur) ease;
}
.site-nav__link:hover { color: var(--paper); background: rgba(53, 224, 210, .06); }
.site-nav__idx { font-family: var(--font-num); font-size: 11px; font-weight: 700; opacity: .72; }
.site-nav__link[aria-current="page"] { color: var(--paper); border-bottom-color: var(--cyan); }
.site-nav__link[aria-current="page"] .site-nav__idx { color: var(--amber); opacity: 1; }

/* ---------- 12. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(40px, 6vw, 80px);
  background: var(--ink);
  border-top: 1px solid var(--line-soft);
}
.site-footer::before {
  content: ""; position: absolute; left: 0; right: 0; top: 0; height: 3px;
  background: linear-gradient(90deg, var(--cyan) 0 16%, var(--amber) 16% 30%, var(--clay) 30% 40%, rgba(201, 212, 232, .25) 40% 100%);
}

.footer-head {
  display: flex; flex-wrap: wrap; gap: 16px 22px; align-items: flex-start; justify-content: space-between;
  padding-block: clamp(28px, 4vw, 46px) 20px;
  border-bottom: 1px solid var(--line-hair);
}
.footer-brand { display: flex; gap: 14px; align-items: flex-start; max-width: 540px; }
.footer-brand .brand-mark { margin-top: 5px; }
.footer-brand__text { display: grid; gap: 4px; }
.footer-brand__name { font-family: var(--font-head); font-size: var(--fs-h4); font-weight: 800; letter-spacing: .02em; color: var(--paper); }
.footer-brand__desc { font-size: 13.5px; line-height: 1.7; color: var(--stone); max-width: 46ch; }

.footer-grid {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 36px);
  padding-block: clamp(26px, 3.6vw, 42px);
}
.footer-col { min-width: 0; }
.footer-col__title {
  font-size: var(--fs-micro); font-weight: 800; letter-spacing: .2em;
  color: var(--cyan); padding-bottom: 9px; margin-bottom: 14px;
  border-bottom: 1px solid var(--line-hair);
}
.footer-list { display: grid; gap: 9px; }
.footer-list__item { display: flex; }
.footer-list__link {
  font-size: 14px; color: var(--on-dark-dim);
  transition: color var(--dur) ease, padding-left var(--dur) ease;
}
.footer-list__link:hover { color: var(--cyan); padding-left: 4px; }
.footer-list__note { font-size: 12.5px; line-height: 1.6; color: var(--stone); }

.footer-bottom {
  display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: center; justify-content: space-between;
  padding-block: 18px 28px;
  border-top: 1px solid var(--line-hair);
  font-size: var(--fs-note); color: var(--stone);
}
.footer-legal { display: flex; flex-wrap: wrap; gap: 6px 16px; align-items: center; }
.footer-contact { display: flex; flex-wrap: wrap; gap: 6px 14px; align-items: center; }
.footer-contact__label { font-size: var(--fs-micro); letter-spacing: .12em; color: var(--stone); }
.footer-contact__item { font-family: var(--font-num); font-weight: 700; color: var(--on-dark-dim); }
.footer-versions {
  display: flex; flex-wrap: wrap; gap: 8px 12px; align-items: center;
  width: 100%; padding-top: 14px; border-top: 1px dashed var(--line-hair);
}
.footer-versions__label { font-size: var(--fs-micro); font-weight: 700; letter-spacing: .2em; color: var(--stone); }
.footer-version {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12.5px; color: var(--on-dark-dim);
  border: 1px solid var(--line-soft); border-radius: 2px; padding: 4px 10px;
  transition: border-color var(--dur) ease, color var(--dur) ease, background var(--dur) ease;
}
.footer-version:hover { border-color: var(--cyan); color: var(--cyan); background: rgba(53, 224, 210, .07); }
.footer-version__tag { font-family: var(--font-num); font-weight: 700; color: var(--amber); }

/* ---------- 13. 返回顶部 + 校准进度条 ---------- */
.to-top {
  position: fixed; right: clamp(14px, 3vw, 28px); bottom: clamp(14px, 3vw, 28px); z-index: 80;
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 15px;
  background: var(--ink-2); color: var(--paper);
  border: 1px solid var(--line-soft); border-radius: var(--r);
  font-size: 13px; font-weight: 700;
  box-shadow: 0 14px 32px rgba(10, 16, 36, .55);
  transition: border-color var(--dur) ease, color var(--dur) ease, background var(--dur) ease;
}
.to-top:hover { border-color: var(--amber); color: var(--amber); background: rgba(233, 162, 59, .1); }
.to-top[hidden] { display: none; }

.scroll-meter {
  position: fixed; top: 0; left: 0; right: 0; height: 2px; z-index: 90;
  background: rgba(201, 212, 232, .12);
  pointer-events: none;
}
.scroll-meter__fill {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--cyan), var(--amber));
  transition: width .18s linear;
}

/* ---------- 14. 显现动效 ---------- */
.has-reveal [data-reveal] { opacity: 0; transform: translateY(12px); }
.has-reveal [data-reveal].is-in {
  opacity: 1; transform: none;
  transition: opacity .3s ease, transform .3s ease;
}

/* ---------- 15. 焦点可见 ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 2px;
}
.section--paper :focus-visible, .plate :focus-visible { outline-color: var(--clay); }

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1080px) {
  .site-nav__link { padding: 9px 9px; font-size: 14px; }
  .util-card { min-width: 216px; }
}

@media (max-width: 900px) {
  html { scroll-padding-top: 150px; }
  :root { --sticky-gap: 16px; }

  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute; left: 0; right: 0; top: 100%;
    flex-direction: column; gap: 0;
    background: var(--ink-2);
    border: 1px solid var(--line-soft); border-top: 0;
    border-radius: 0 0 var(--r) var(--r);
    max-height: 0; visibility: hidden; overflow: hidden;
    box-shadow: 0 20px 44px rgba(10, 16, 36, .55);
    transition: max-height .28s ease, visibility .28s ease;
  }
  .site-nav[data-open] {
    max-height: min(70vh, 520px);
    visibility: visible;
    overflow-y: auto;
  }
  .site-nav__item { display: block; }
  .site-nav__link {
    width: 100%; justify-content: flex-start; gap: 12px;
    padding: 14px 18px; font-size: 15.5px;
    border-bottom: 1px solid var(--line-hair);
  }
  .site-nav__item:last-child .site-nav__link { border-bottom: 0; }
  .site-nav__link[aria-current="page"] {
    border-bottom-color: var(--line-hair);
    background: rgba(53, 224, 210, .09);
    box-shadow: inset 3px 0 0 var(--cyan);
  }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  .utility-bar__title { display: none; }
  .utility-bar__inner { padding-block: 9px; }
  .utility-bar__list { gap: 8px; }
  .util-card { min-width: 208px; padding: 8px 12px; }
  .util-card__hint { max-width: 150px; }
  .brand-rail__inner { flex-wrap: wrap; }
  .brand-rail__meta { width: 100%; justify-content: flex-start; }
  .lang-tag { border-left: 0; padding-left: 0; }
}

@media (max-width: 560px) {
  body { font-size: 15.5px; }
  h1, .h1 { font-size: 30px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .footer-version { width: 100%; justify-content: flex-start; }
  .folder-meta { display: none; }
  .to-top { padding: 9px 12px; font-size: 12.5px; }
}

/* ---------- 17. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .has-reveal [data-reveal] { opacity: 1; transform: none; }
  .btn:hover, .util-card:hover { transform: none; }
}