/* ==========================================================================
   万利官网 · 共享样式表 /assets/site.css
   技术蓝图式网格 + 湖蓝橙冷暖对撞 + 粗野主义粗边框硬投影
   ========================================================================== */

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

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

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%; }

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

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

:focus-visible {
  outline: 3px solid #FF7A2F;
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- CSS 变量 ---------- */
:root {
  --ink: #0B1B3A;
  --ink-2: #16274D;
  --blue: #1E7FD0;
  --blue-lt: #4FB3E8;
  --mist: #BBDDF3;
  --orange: #FF7A2F;
  --orange-lt: #FFC08A;
  --snow: #F4F7FB;
  --graphite: #10161F;
  --gray: #6E82A0;

  --wrap: 1180px;
  --gutter: clamp(1rem, 4vw, 2.5rem);

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

  --line: rgba(187, 221, 243, 0.22);
  --hard: 6px 6px 0 #0B1B3A;
  --hard-dark: 6px 6px 0 #050C1C;
  --header-h: 76px;
}

/* ---------- 中文排版基线 ---------- */
body {
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.85;
  letter-spacing: 0.01em;
  color: var(--graphite);
  background-color: var(--snow);
  background-image: radial-gradient(rgba(30, 127, 208, 0.13) 1px, transparent 1.1px);
  background-size: 24px 24px;
  min-height: 100vh;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--ink);
}

h1 { font-size: clamp(2.5rem, 1.6rem + 4.4vw, 5.25rem); line-height: 1.05; }
h2 { font-size: clamp(1.75rem, 1.1rem + 2.1vw, 2.25rem); }
h3 { font-size: clamp(1.25rem, 1rem + 1vw, 1.5rem); }
h4 { font-size: 1.15rem; }

p { max-width: 68ch; }

strong { font-weight: 900; }

/* ---------- 布局工具 ---------- */
.wrap {
  width: min(var(--wrap), 100% - (var(--gutter) * 2));
  margin-inline: auto;
}

.section { padding-block: clamp(3rem, 7vw, 6rem); }

.section--dark {
  background-color: var(--ink);
  color: var(--mist);
  background-image:
    linear-gradient(rgba(187, 221, 243, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(187, 221, 243, 0.06) 1px, transparent 1px);
  background-size: 56px 56px;
}

.section--dark h2,
.section--dark h3,
.section--dark h4 { color: var(--snow); }

.grid { display: grid; gap: clamp(1.25rem, 3vw, 2.5rem); }
.grid--5-7 { grid-template-columns: 5fr 7fr; }
.grid--7-5 { grid-template-columns: 7fr 5fr; }
.grid--3-5-4 { grid-template-columns: 3fr 5fr 4fr; }

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

/* ---------- 标签 / 文字 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--blue);
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: currentColor;
  flex: none;
}

.section--dark .eyebrow { color: var(--blue-lt); }

.rule {
  display: block;
  height: 2px;
  border: 0;
  background-image: repeating-linear-gradient(90deg, var(--blue) 0 18px, transparent 18px 28px);
  opacity: 0.65;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 16px;
  line-height: 1.2;
  padding: 0.85rem 1.5rem;
  border: 2px solid var(--ink);
  background: var(--snow);
  color: var(--ink);
  box-shadow: var(--hard);
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.btn:hover { transform: translate(3px, 3px); box-shadow: 3px 3px 0 #0B1B3A; }

.btn--primary {
  background: var(--orange);
  color: var(--ink);
}

.btn--ghost {
  background: transparent;
  color: var(--snow);
  border-color: var(--blue-lt);
  box-shadow: 6px 6px 0 rgba(30, 127, 208, 0.35);
}

.btn--ghost:hover { box-shadow: 3px 3px 0 rgba(30, 127, 208, 0.35); }

.btn--sm { font-size: 14px; padding: 0.55rem 1rem; }

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-block: 1rem;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--gray);
}

.breadcrumbs__item { display: inline-flex; align-items: center; }
.breadcrumbs__item::after { content: "/"; margin-left: 0.5rem; color: var(--blue); }
.breadcrumbs__item:last-child::after { content: ""; }
.breadcrumbs a:hover { color: var(--blue); }

/* ---------- 长文容器 ---------- */
.prose {
  font-size: 18px;
  line-height: 1.9;
  color: #22304A;
  max-width: 74ch;
}

.prose > * + * { margin-top: 1.4em; }

.prose h2 {
  margin-top: 2.4em;
  padding-left: 0.9rem;
  border-left: 6px solid var(--orange);
  font-size: clamp(1.4rem, 1.1rem + 1.2vw, 1.75rem);
}

.prose h3 { margin-top: 1.9em; }

.prose ul li {
  position: relative;
  padding-left: 1.4rem;
}

.prose ul li + li { margin-top: 0.5em; }

.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 8px;
  height: 8px;
  background: var(--blue);
}

.prose a {
  color: var(--blue);
  border-bottom: 2px solid rgba(30, 127, 208, 0.35);
}

.prose a:hover { border-bottom-color: var(--orange); }

/* ---------- 卡片 ---------- */
.card {
  display: block;
  padding: clamp(1.1rem, 2.4vw, 1.75rem);
  background: #FFFFFF;
  border: 2px solid var(--ink);
  box-shadow: var(--hard);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.card:hover { transform: translate(4px, 4px); box-shadow: 2px 2px 0 #0B1B3A; }

.card--dark {
  background: var(--ink-2);
  color: var(--mist);
  border-color: var(--blue);
  box-shadow: var(--hard-dark);
}

.card--dark:hover { box-shadow: 2px 2px 0 #050C1C; }
.card--dark h3, .card--dark h4 { color: var(--snow); }

/* ---------- 图片占位容器（页面阶段直接放 <img>） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 2px solid var(--ink);
  background-image: linear-gradient(135deg, var(--blue) 0%, var(--blue-lt) 46%, var(--orange) 100%);
  box-shadow: var(--hard);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(135deg, rgba(30, 127, 208, 0.4), rgba(255, 122, 47, 0.3));
  mix-blend-mode: multiply;
  opacity: 0.55;
}

.media-frame__label {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  padding: 0.3rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--snow);
  background: var(--ink);
  border-top: 2px solid var(--blue);
  border-right: 2px solid var(--blue);
}

.media-frame--21x9 { aspect-ratio: 21 / 9; }
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

/* ---------- 章节目录跟随 ---------- */
.toc {
  position: sticky;
  top: calc(var(--header-h) + 1rem);
  padding-left: 1rem;
  border-left: 2px solid rgba(30, 127, 208, 0.35);
}

.toc__title {
  margin-bottom: 0.6rem;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  color: var(--gray);
}

.toc__list { display: grid; gap: 0.3rem; }

.toc__link {
  display: block;
  padding: 0.25rem 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14.5px;
  color: var(--gray);
  transition: color 0.18s ease, padding-left 0.18s ease, box-shadow 0.18s ease;
}

.toc__link:hover { color: var(--blue); }

.toc__link.is-active {
  color: var(--ink);
  padding-left: 0.55rem;
  box-shadow: inset 3px 0 0 var(--orange);
}

/* ---------- 显现动效 ---------- */
.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 1rem;
  top: -120px;
  z-index: 200;
  padding: 0.7rem 1.1rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  color: var(--ink);
  background: var(--orange);
  border: 2px solid var(--ink);
  box-shadow: 4px 4px 0 #050C1C;
  transition: top 0.2s ease;
}

.skip-link:focus { top: 0.75rem; }

/* ---------- 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  color: var(--snow);
  background-color: var(--ink);
  border-bottom: 2px solid var(--blue);
  background-image:
    linear-gradient(rgba(187, 221, 243, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(187, 221, 243, 0.07) 1px, transparent 1px);
  background-size: 48px 48px;
}

.site-header__rail {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(0.85rem, 2.6vw, 2.25rem);
  min-height: var(--header-h);
  padding-block: 0.6rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding-block: 0.3rem;
}

.brand__mark {
  position: relative;
  flex: none;
  width: 38px;
  height: 38px;
  border: 2px solid var(--blue-lt);
  background-image: linear-gradient(135deg, var(--blue) 0 48%, var(--orange) 52% 100%);
  box-shadow: 4px 4px 0 rgba(30, 127, 208, 0.45);
}

.brand__mark::after {
  content: "";
  position: absolute;
  right: -6px;
  bottom: -6px;
  width: 10px;
  height: 10px;
  background: var(--orange);
  border: 2px solid var(--ink);
}

.brand__text { display: flex; flex-direction: column; line-height: 1.15; }

.brand__name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.2rem, 1rem + 0.7vw, 1.6rem);
  letter-spacing: 0.02em;
  color: var(--snow);
}

.brand__tagline {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  color: var(--blue-lt);
}

.site-header__coord {
  padding-left: 1rem;
  border-left: 2px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: rgba(187, 221, 243, 0.6);
  white-space: nowrap;
}

/* 移动端按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  margin-left: auto;
  padding: 0.5rem 0.75rem;
  color: var(--snow);
  background: var(--ink-2);
  border: 2px solid var(--blue-lt);
  box-shadow: 3px 3px 0 rgba(5, 12, 28, 0.8);
}

.nav-toggle__icon { display: grid; gap: 3px; }
.nav-toggle__bar { display: block; width: 16px; height: 2px; background: var(--snow); }
.nav-toggle__text {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
}
.nav-toggle[aria-expanded="true"] { border-color: var(--orange); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar { background: var(--orange); }

/* 导航路径 */
.site-nav { margin-left: auto; }

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(0.6rem, 1.5vw, 1.5rem);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: clamp(0.6rem, 1.4vw, 1.4rem);
}

.nav-item::before {
  content: "";
  flex: none;
  width: clamp(10px, 1.4vw, 24px);
  height: 2px;
  background-image: linear-gradient(90deg, rgba(187, 221, 243, 0.18), var(--blue));
}

.nav-item:first-child::before { display: none; }

.nav-node {
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
  padding: 0.35rem 0.15rem;
  border-bottom: 2px solid transparent;
  color: var(--mist);
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.nav-node__idx {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: rgba(187, 221, 243, 0.62);
}

.nav-node__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15.5px;
  white-space: nowrap;
}

.nav-node:hover { color: #FFFFFF; border-bottom-color: var(--orange); }
.nav-node:hover .nav-node__idx { color: var(--orange-lt); }

.nav-node[aria-current="page"] {
  padding-inline: 0.6rem;
  color: var(--ink);
  background: var(--orange);
  border-bottom-color: var(--orange);
  box-shadow: 4px 4px 0 rgba(30, 127, 208, 0.5);
}

.nav-node[aria-current="page"] .nav-node__idx { color: rgba(11, 27, 58, 0.78); }

/* 页头进度线 */
.site-header__progress {
  position: absolute;
  left: 0;
  bottom: -2px;
  z-index: 2;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: left center;
  background-image: linear-gradient(90deg, var(--blue), var(--blue-lt) 45%, var(--orange));
}

/* ---------- 底部悬浮快捷条 ---------- */
.quick-bar {
  position: fixed;
  left: 50%;
  bottom: clamp(0.75rem, 2vw, 1.25rem);
  z-index: 90;
  display: flex;
  align-items: stretch;
  max-width: calc(100% - 1.5rem);
  background: var(--ink-2);
  border: 2px solid var(--blue);
  box-shadow: 6px 6px 0 rgba(5, 12, 28, 0.65);
  opacity: 0;
  visibility: hidden;
  transform: translate(-50%, 170%);
  transition: transform 0.35s cubic-bezier(0.2, 0.9, 0.35, 1.35), opacity 0.3s ease, visibility 0.35s ease;
}

.quick-bar[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, 0);
}

.quick-bar__item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem clamp(0.7rem, 2vw, 1.1rem);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  color: var(--snow);
  border-right: 2px solid rgba(187, 221, 243, 0.2);
  white-space: nowrap;
  transition: background-color 0.18s ease, color 0.18s ease;
}

.quick-bar__item:last-child { border-right: 0; }
.quick-bar__item:hover { background: var(--blue); color: #FFFFFF; }

.quick-bar__item[aria-pressed="true"] {
  background: var(--orange);
  color: var(--ink);
}

.quick-bar__glyph {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1;
  color: var(--orange-lt);
}

.quick-bar__item:hover .quick-bar__glyph { color: #FFFFFF; }
.quick-bar__item[aria-pressed="true"] .quick-bar__glyph { color: var(--ink); }

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  color: var(--mist);
  background-color: var(--ink);
  border-top: 3px solid var(--blue);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(115deg, rgba(187, 221, 243, 0.07) 0 1px, transparent 1px 22px),
    repeating-linear-gradient(65deg, rgba(30, 127, 208, 0.11) 0 1px, transparent 1px 34px);
}

.footer-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.35fr 1.45fr 1fr 1fr;
  gap: clamp(1.5rem, 3vw, 2.75rem);
  padding-block: clamp(2.5rem, 5vw, 4rem) clamp(2rem, 4vw, 3rem);
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  min-width: 0;
}

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--line);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: 0.05em;
  color: var(--snow);
}

.footer-col__num {
  padding: 0.1rem 0.35rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink);
  background: var(--orange);
}

.footer-brand__name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.35rem, 1.1rem + 0.9vw, 1.75rem);
  color: var(--snow);
}

.footer-brand__tagline {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--blue-lt);
}

.footer-brand__note {
  max-width: 30ch;
  font-size: 15.5px;
  line-height: 1.75;
  color: rgba(244, 247, 251, 0.8);
}

.footer-brand__coord {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: rgba(187, 221, 243, 0.5);
}

.footer-service {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  padding: 1rem;
  background: rgba(30, 127, 208, 0.09);
  border: 2px solid var(--blue);
  box-shadow: 5px 5px 0 rgba(5, 12, 28, 0.55);
}

.footer-service__list { display: grid; gap: 0.45rem; }

.footer-service__item {
  position: relative;
  padding-left: 1.1rem;
  font-size: 15px;
  line-height: 1.6;
  color: var(--mist);
}

.footer-service__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 7px;
  height: 7px;
  background: var(--orange);
}

.footer-contact__link {
  align-self: flex-start;
  padding: 0.5rem 0.85rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 14.5px;
  color: var(--ink);
  background: var(--orange);
  border: 2px solid var(--ink);
  box-shadow: 3px 3px 0 rgba(5, 12, 28, 0.7);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.footer-contact__link:hover { transform: translate(3px, 3px); box-shadow: 0 0 0 rgba(5, 12, 28, 0.7); }

.footer-contact { display: grid; gap: 0.5rem; }

.footer-contact__row {
  display: grid;
  grid-template-columns: 3.2rem 1fr;
  gap: 0.6rem;
  align-items: start;
  font-size: 14.5px;
  line-height: 1.6;
}

.footer-contact__label {
  padding-top: 0.15rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--blue-lt);
}

.footer-contact__value {
  color: rgba(244, 247, 251, 0.88);
  overflow-wrap: anywhere;
}

.footer-links { display: grid; gap: 0.55rem; }

.footer-link {
  display: inline-block;
  font-size: 15.5px;
  color: var(--mist);
  border-bottom: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

.footer-link:hover {
  color: #FFFFFF;
  border-bottom-color: var(--orange);
  transform: translateX(3px);
}

.footer-meta { font-size: 14.5px; }

.footer-meta__icp {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.footer-meta__copy { color: rgba(244, 247, 251, 0.72); }

.footer-meta__beat {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--orange-lt);
}

.footer-meta__dot {
  flex: none;
  width: 8px;
  height: 8px;
  background: var(--orange);
  animation: wl-pulse 2s ease-in-out infinite;
}

@keyframes wl-pulse {
  50% { opacity: 0.3; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .site-header__coord { display: none; }
}

@media (max-width: 1020px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 960px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: absolute;
    left: calc(-1 * var(--gutter));
    right: calc(-1 * var(--gutter));
    top: 100%;
    margin-left: 0;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    background: var(--ink-2);
    border-top: 2px solid var(--blue);
    border-bottom: 2px solid var(--blue);
    box-shadow: 0 20px 40px rgba(5, 12, 28, 0.55);
    transition: max-height 0.35s ease, opacity 0.25s ease, visibility 0.35s ease;
  }

  .site-nav[data-open] {
    max-height: 78vh;
    overflow-y: auto;
    opacity: 1;
    visibility: visible;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 1rem var(--gutter) 1.4rem;
  }

  .nav-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
  }

  .nav-item::before {
    width: 2px;
    height: 16px;
    margin-left: 3px;
    background-image: linear-gradient(180deg, var(--blue), var(--mist));
  }

  .nav-node {
    width: 100%;
    justify-content: flex-start;
    padding: 0.7rem 0.2rem;
    border-bottom: 2px solid transparent;
  }

  .nav-item + .nav-item .nav-node { border-top: 1px dashed rgba(187, 221, 243, 0.2); }

  .nav-node__label { font-size: 17px; }

  .nav-node[aria-current="page"] { width: 100%; }

  .toc { position: static; }
}

@media (max-width: 900px) {
  .grid--5-7,
  .grid--7-5,
  .grid--3-5-4 { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 17px; }

  .footer-grid { grid-template-columns: 1fr; gap: 1.9rem; }

  .quick-bar__item { font-size: 13px; padding: 0.6rem 0.7rem; }

  .brand__mark { width: 32px; height: 32px; }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

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

  .quick-bar { transform: translate(-50%, 0); }
  .quick-bar:not([data-visible]) { visibility: hidden; opacity: 0; }
}