/* ==========================================================================
   百博主页 · 共享样式 /assets/site.css
   目录型内容地图 · 双层页头 · 墨黑页脚 · 仪表盘式配色节奏
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 变量
   -------------------------------------------------------------------------- */
:root {
  /* 色彩 */
  --ink: #0E1116;
  --deep: #0B2A5B;
  --blue: #1D4ED8;
  --orange: #FF6A2A;
  --cyan: #37E0C8;
  --stone: #6B7280;
  --moss: #4F6F52;
  --clay: #A95C3F;
  --cream: #F4F0E8;
  --paper: #FCFAF5;
  --mist: #DCE6F5;

  /* 线条 */
  --line: rgba(14, 17, 22, .13);
  --line-strong: rgba(14, 17, 22, .26);
  --line-invert: rgba(244, 240, 232, .15);

  /* 字体 */
  --font-display: "Oswald", "Barlow Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Heiti SC", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  /* 节奏 */
  --shell: 1280px;
  --dur: 190ms;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --cut: 14px;
  --header-h: 112px;
}

/* --------------------------------------------------------------------------
   2. Reset 与基础排版
   -------------------------------------------------------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-h);
}

body {
  margin: 0;
  background-color: var(--paper);
  background-image:
    linear-gradient(180deg, rgba(220, 230, 245, .38) 0, rgba(252, 250, 245, 0) 420px);
  background-repeat: no-repeat;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg { display: block; max-width: 100%; }
a { color: var(--blue); text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -.012em;
  color: var(--ink);
}
h1 { font-size: clamp(34px, 4.6vw, 60px); }
h2 { font-size: clamp(26px, 3vw, 38px); }
h3 { font-size: clamp(20px, 2vw, 24px); }
h4 { font-size: 18px; }

.mono {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  font-variant-numeric: tabular-nums;
}

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
  border-radius: 2px;
}
.header-upper :focus-visible,
.site-footer :focus-visible { outline-color: var(--cyan); }

::selection { background: var(--orange); color: var(--ink); }

/* --------------------------------------------------------------------------
   3. 布局容器与切角工具
   -------------------------------------------------------------------------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 40px);
}

.cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}
.cut--tl {
  clip-path: polygon(var(--cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--cut));
}

.grid { display: grid; gap: clamp(16px, 2vw, 28px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--rail {
  grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
  align-items: start;
  gap: clamp(24px, 3vw, 48px);
}

/* --------------------------------------------------------------------------
   4. 跳过链接
   -------------------------------------------------------------------------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -100px;
  z-index: 200;
  display: inline-block;
  padding: 12px 22px;
  background: var(--blue);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  transition: top var(--dur) var(--ease);
}
.skip-link:focus { top: 8px; }

/* --------------------------------------------------------------------------
   5. 页头 · 上层品牌信息带
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--cream);
  border-bottom: 1px solid var(--line-strong);
}

.header-upper {
  background-color: var(--ink);
  background-image:
    repeating-linear-gradient(90deg, rgba(244, 240, 232, .07) 0 1px, transparent 1px 88px),
    linear-gradient(90deg, rgba(29, 78, 216, .34), transparent 58%);
  color: var(--cream);
  border-bottom: 1px solid var(--line-invert);
}

.header-upper__inner {
  display: flex;
  align-items: center;
  gap: 20px;
  min-height: 46px;
  padding-block: 6px;
}

.header-upper__utility {
  margin-inline-start: auto;
  color: rgba(244, 240, 232, .66);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  white-space: nowrap;
}

/* 品牌锁定区 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: none;
  color: var(--cream);
  transition: color var(--dur) var(--ease);
}
.brand:hover { color: var(--cyan); }

.brand__mark {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  background: var(--blue);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  font-variant-numeric: tabular-nums;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.12;
}
.brand__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .03em;
}
.brand__note {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .3em;
  color: var(--cyan);
}

/* 版本铭牌 */
.version-badge {
  display: inline-flex;
  align-items: stretch;
  flex: none;
  border: 1px solid rgba(244, 240, 232, .24);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}
.version-badge__key {
  display: inline-flex;
  align-items: center;
  padding: 5px 10px;
  background: rgba(244, 240, 232, .1);
  color: rgba(244, 240, 232, .82);
  white-space: nowrap;
}
.version-badge__val {
  display: inline-flex;
  align-items: center;
  padding: 5px 10px;
  background: var(--cyan);
  color: var(--ink);
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   6. 页头 · 下层栏目导航带
   -------------------------------------------------------------------------- */
.header-lower {
  position: relative;
  background: var(--cream);
}

.header-lower__inner {
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 62px;
  padding-block: 6px;
}

.site-nav { flex: 1 1 auto; }

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 10px 14px;
  color: var(--ink);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .012em;
  border-radius: 2px;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 7px;
  height: 2px;
  background: var(--orange);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}
.site-nav__link:hover {
  color: var(--deep);
  background: rgba(29, 78, 216, .06);
}
.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] {
  color: var(--deep);
  font-weight: 700;
  background: rgba(29, 78, 216, .1);
}
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--blue);
}

/* 移动端栏目按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  flex: none;
  padding: 9px 14px;
  border: 1px solid var(--line-strong);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 8px 100%, 0 calc(100% - 8px));
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-toggle:hover { background: var(--mist); }

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: space-between;
  width: 16px;
  height: 12px;
}
.nav-toggle__bars span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--ink);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

.nav-toggle__label { line-height: 1; }

/* 站内索引入口 */
.index-entry {
  margin-inline-start: auto;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
  padding: 10px 18px;
  background: var(--ink);
  color: var(--cream);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .12em;
  clip-path: polygon(10px 0, 100% 0, 100% 100%, 0 100%, 0 10px);
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.index-entry:hover { background: var(--blue); color: #fff; }
.index-entry__icon { color: var(--cyan); }
.index-entry:hover .index-entry__icon { color: var(--cyan); }

/* 滚动进度轨 */
.scroll-track {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  pointer-events: none;
}
.scroll-track__fill {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--blue) 0, var(--cyan) 68%, var(--orange) 100%);
  transition: transform 90ms linear;
}

/* --------------------------------------------------------------------------
   7. 页脚
   -------------------------------------------------------------------------- */
.site-footer {
  position: relative;
  margin-top: 0;
  background-color: var(--ink);
  background-image:
    repeating-linear-gradient(90deg, rgba(244, 240, 232, .055) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(244, 240, 232, .04) 0 1px, transparent 1px 96px),
    linear-gradient(158deg, rgba(29, 78, 216, .28) 0, rgba(11, 42, 91, .1) 42%, rgba(14, 17, 22, 0) 70%);
  color: rgba(244, 240, 232, .8);
  overflow: hidden;
}

.footer-ridge {
  display: block;
  height: 6px;
  width: 100%;
  background: linear-gradient(90deg, var(--orange) 0 22%, var(--cyan) 22% 46%, var(--blue) 46% 100%);
}

.footer-shell { position: relative; }

.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1.35fr) minmax(160px, .9fr) minmax(250px, 1.2fr);
  gap: 48px 56px;
  padding-block: 56px 40px;
  border-bottom: 1px solid var(--line-invert);
}

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

.footer-brand__link {
  font-family: var(--font-display);
  font-size: 27px;
  font-weight: 700;
  letter-spacing: .04em;
  line-height: 1.1;
  color: var(--cream);
  transition: color var(--dur) var(--ease);
}
.footer-brand__link:hover { color: var(--cyan); }

.footer-brand__tag {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .36em;
  color: var(--cyan);
}

.footer-brand__desc {
  margin-top: 16px;
  max-width: 32ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(244, 240, 232, .68);
}

.footer-brand__badge {
  display: inline-flex;
  align-items: center;
  margin-top: 20px;
  padding: 5px 12px;
  border: 1px solid rgba(244, 240, 232, .22);
  color: var(--cream);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}

.footer-brand__cta { margin-top: 18px; }

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

.footer-nav__title,
.footer-contact__title {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .24em;
  color: var(--orange);
  text-transform: uppercase;
}

.footer-nav__list {
  display: grid;
  gap: 2px;
  margin-top: 16px;
}
.footer-nav__list a {
  display: inline-block;
  padding: 6px 0;
  color: rgba(244, 240, 232, .82);
  font-size: 15px;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.footer-nav__list a:hover {
  color: var(--cyan);
  border-bottom-color: rgba(55, 224, 200, .55);
}

.footer-contact { min-width: 0; }

.footer-contact__list { margin-top: 16px; }

.footer-contact__row {
  display: grid;
  grid-template-columns: 4.2em minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 9px 0;
  border-bottom: 1px dashed rgba(244, 240, 232, .16);
}

.footer-contact__key {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: rgba(244, 240, 232, .5);
  padding-top: 2px;
}

.footer-contact__val {
  color: var(--cream);
  font-size: 14.5px;
  line-height: 1.65;
  overflow-wrap: anywhere;
}

.footer-contact__note {
  margin-top: 16px;
  max-width: 42ch;
  font-size: 12.5px;
  line-height: 1.8;
  color: rgba(244, 240, 232, .52);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 32px;
  padding-block: 24px 34px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 22px;
  font-size: 13.5px;
}
.footer-legal a {
  color: rgba(244, 240, 232, .74);
  border-bottom: 1px solid rgba(244, 240, 232, .2);
  padding-bottom: 1px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.footer-legal a:hover { color: var(--cyan); border-bottom-color: var(--cyan); }

.footer-copy {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(244, 240, 232, .55);
  font-variant-numeric: tabular-nums;
}
.footer-copy__sep { color: rgba(244, 240, 232, .3); }

/* --------------------------------------------------------------------------
   8. 通用按钮 / 面包屑 / 正文容器
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 24px;
  background: var(--blue);
  color: #fff;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .06em;
  line-height: 1.3;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.btn:hover { background: var(--deep); color: #fff; }
.btn--onDark {
  background: rgba(55, 224, 200, .08);
  color: var(--cyan);
  box-shadow: inset 0 0 0 1px rgba(55, 224, 200, .5);
}
.btn--onDark:hover {
  background: var(--cyan);
  color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--cyan);
}

.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--stone);
}
.crumbs a {
  color: var(--deep);
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 1px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.crumbs a:hover { color: var(--blue); border-bottom-color: var(--blue); }
.crumbs__sep { color: var(--stone); opacity: .6; }
.crumbs [aria-current="page"] { color: var(--ink); }

.prose {
  max-width: 78ch;
  font-size: 17px;
  line-height: 1.85;
  color: #1b2028;
}
.prose > * + * { margin-top: 1.05em; }
.prose h2 {
  margin-top: 2.2em;
  padding-top: .7em;
  border-top: 1px solid var(--line);
  font-size: clamp(22px, 2.4vw, 28px);
}
.prose h3 { margin-top: 1.8em; font-size: 21px; }
.prose ul, .prose ol { padding-left: 1.4em; list-style: revert; }
.prose li + li { margin-top: .4em; }
.prose a {
  color: var(--blue);
  border-bottom: 1px solid rgba(29, 78, 216, .35);
  transition: border-color var(--dur) var(--ease);
}
.prose a:hover { border-bottom-color: var(--blue); }

/* --------------------------------------------------------------------------
   9. 索引轨道 / 章节标题带 / 标签
   -------------------------------------------------------------------------- */
.index-rail {
  position: sticky;
  top: calc(var(--header-h) + 8px);
  align-self: start;
}
.index-rail__title {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .22em;
  color: var(--stone);
  margin-bottom: 14px;
}
.index-rail__list {
  display: grid;
  gap: 2px;
  border-left: 2px solid var(--line-strong);
}
.index-rail__list a {
  display: block;
  margin-left: -2px;
  padding: 8px 0 8px 16px;
  border-left: 2px solid transparent;
  color: var(--ink);
  font-size: 14.5px;
  line-height: 1.5;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.index-rail__list a:hover {
  color: var(--blue);
  background: rgba(29, 78, 216, .05);
}
.index-rail__list a[aria-current="true"],
.index-rail__list a[aria-current="page"] {
  color: var(--deep);
  font-weight: 700;
  border-left-color: var(--orange);
  background: rgba(255, 106, 42, .08);
}

.sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 20px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--ink);
  margin-bottom: clamp(20px, 3vw, 32px);
}
.sec-head__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}
.sec-head__title {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 700;
  line-height: 1.2;
}
.sec-head__note {
  margin-inline-start: auto;
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  background: var(--mist);
  color: var(--deep);
  border: 1px solid rgba(11, 42, 91, .18);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  line-height: 1.6;
}
.tag--moss { background: rgba(79, 111, 82, .12); color: var(--moss); border-color: rgba(79, 111, 82, .32); }
.tag--clay { background: rgba(169, 92, 63, .12); color: var(--clay); border-color: rgba(169, 92, 63, .32); }
.tag--signal { background: var(--orange); color: var(--ink); border-color: transparent; font-weight: 600; }

/* --------------------------------------------------------------------------
   10. 可复用图片容器（供页面阶段放置图片占位）
   -------------------------------------------------------------------------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--mist);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}
.media img,
.media svg,
.media > video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--21x9 { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }

.media--grid::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(14, 17, 22, .12) 0 1px, transparent 1px 40px),
    repeating-linear-gradient(0deg, rgba(14, 17, 22, .12) 0 1px, transparent 1px 40px);
}

.media__badge {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  padding: 6px 12px;
  background: var(--ink);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  font-variant-numeric: tabular-nums;
}

/* --------------------------------------------------------------------------
   11. 响应式
   -------------------------------------------------------------------------- */
@media (max-width: 1080px) {
  .site-nav__link { padding: 10px 11px; font-size: 14.5px; }
}

@media (max-width: 1000px) {
  .footer-top {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 36px 44px;
    padding-block: 44px 32px;
  }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  :root { --header-h: 104px; }

  .header-upper__utility { display: none; }

  .header-lower__inner {
    justify-content: space-between;
    gap: 12px;
    min-height: 58px;
  }

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

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    max-height: calc(100vh - 104px);
    overflow-y: auto;
    padding: 6px clamp(16px, 4vw, 40px) 18px;
    background: var(--paper);
    border-top: 1px solid var(--line-strong);
    border-bottom: 1px solid var(--line-strong);
    box-shadow: 0 26px 44px -30px rgba(14, 17, 22, .7);
  }
  .site-nav[data-open="true"] { display: block; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .site-nav__link {
    display: block;
    width: 100%;
    padding: 14px 4px;
    font-size: 16px;
    border-bottom: 1px dashed var(--line);
    border-radius: 0;
  }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] {
    background: rgba(29, 78, 216, .09);
    box-shadow: inset 3px 0 0 var(--orange);
    padding-left: 12px;
  }

  .index-entry { margin-inline-start: 0; padding: 9px 14px; font-size: 12px; }

  .grid--2, .grid--3, .grid--4, .grid--rail { grid-template-columns: minmax(0, 1fr); }

  .index-rail {
    position: static;
    border: 1px solid var(--line);
    background: var(--cream);
    padding: 16px 18px;
  }
  .index-rail__list { border-left: 0; }
  .index-rail__list a { margin-left: 0; padding-left: 0; border-left: 0; border-bottom: 1px solid var(--line); }
  .index-rail__list a[aria-current="true"],
  .index-rail__list a[aria-current="page"] { border-left: 0; box-shadow: inset 3px 0 0 var(--orange); padding-left: 10px; }

  body { font-size: 16px; }
  .prose { font-size: 16px; }
}

@media (max-width: 640px) {
  .footer-top {
    grid-template-columns: minmax(0, 1fr);
    gap: 32px;
    padding-block: 36px 28px;
  }
  .footer-base {
    flex-direction: column;
    align-items: flex-start;
    padding-block: 20px 30px;
  }
  .footer-brand__link { font-size: 24px; }
  .footer-contact__row { grid-template-columns: 3.6em minmax(0, 1fr); }
}

@media (max-width: 560px) {
  .version-badge__key { display: none; }
  .brand__note { letter-spacing: .22em; }
  .sec-head__note { margin-inline-start: 0; width: 100%; }
  .nav-toggle__label { display: none; }
  .nav-toggle { padding: 9px 11px; }
}

@media (max-width: 400px) {
  .brand__mark { width: 32px; height: 32px; }
  .brand__name { font-size: 17px; }
  .index-entry__key { letter-spacing: .04em; }
}

/* --------------------------------------------------------------------------
   12. 可访问性偏好
   -------------------------------------------------------------------------- */
@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;
  }
  .scroll-track__fill { transition: none; }
}

@media print {
  .site-header, .site-footer, .skip-link, .nav-toggle { display: none !important; }
  body { background: #fff; color: #000; }
}