/* =========================================================
   雅博 CN — 共享样式 /assets/site.css
   外框式导航 + 编辑部八栏网格 + 档案室色彩
   ========================================================= */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--top-h) + 18px);
}

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, figcaption, blockquote, dl, dd {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

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

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

table { border-collapse: collapse; }

main { display: block; }

/* ---------- 变量 ---------- */
:root {
  --ink: #12233A;
  --ink-deep: #0A1725;
  --paper: #F7F4EC;
  --paper-2: #E9E4D8;
  --cinnabar: #C0362C;
  --cinnabar-dark: #9E2B23;
  --cinnabar-tint: #F1DAD5;
  --copper: #2E6B5E;
  --copper-tint: #DCE7E2;
  --muted: #6C7480;
  --rule: #C7C0B0;

  --font-head: "Songti SC", STSong, "Noto Serif SC", "Source Han Serif SC", serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", "Roboto Mono", ui-monospace, monospace;

  --rail-w: 76px;
  --top-h: 56px;
  --content-w: 1180px;
  --gap: 24px;

  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --t-fast: 180ms;
  --t-mid: 260ms;
  --t-slow: 320ms;

  --progress: 0;
}

/* ---------- 页面基底 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  min-height: 100vh;
  padding-top: var(--top-h);
  padding-left: var(--rail-w);
  overflow-x: hidden;
}

p { max-width: 68ch; }

/* ---------- 焦点 ---------- */
:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 2px;
}

.rail :focus-visible,
.topbar :focus-visible,
.site-footer :focus-visible {
  outline-color: var(--cinnabar-tint);
}

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: fixed;
  left: var(--rail-w);
  top: 0;
  z-index: 300;
  padding: 11px 20px;
  background: var(--cinnabar);
  color: #fff;
  font-size: 14px;
  letter-spacing: 0.04em;
  transform: translateY(-130%);
  transition: transform var(--t-fast) var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

/* ---------- 页头外框 ---------- */
.site-header {
  position: relative;
  z-index: 120;
}

/* 左：竖排导航轨道 */
.rail {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: 120;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 14px 0 14px;
  background: var(--ink);
  border-right: 1px solid var(--ink-deep);
}

.rail__mark {
  flex: 0 0 auto;
  width: 20px;
  height: 20px;
  margin-bottom: 22px;
  background: var(--cinnabar);
}

.rail__nav {
  flex: 1 1 auto;
  min-height: 0;
  width: 100%;
  overflow-y: auto;
  scrollbar-width: none;
}

.rail__nav::-webkit-scrollbar { display: none; }

.rail__list {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.rail__item {
  position: relative;
  width: 100%;
  display: flex;
  justify-content: center;
}

.rail__item::after {
  content: "";
  position: absolute;
  left: 9px;
  top: 50%;
  width: 6px;
  height: 6px;
  margin-top: -3px;
  border-radius: 50%;
  background: var(--cinnabar);
  transform: scale(0);
  transition: transform var(--t-mid) var(--ease);
}

.rail__item:has(.rail__link[aria-current="page"])::after {
  transform: scale(1);
}

.rail__link {
  display: block;
  writing-mode: vertical-rl;
  text-orientation: upright;
  padding: 14px 0;
  font-size: 15px;
  letter-spacing: 0.22em;
  color: rgba(247, 244, 236, 0.66);
  transition: color var(--t-fast) var(--ease);
}

.rail__link:hover { color: var(--paper); }

.rail__link[aria-current="page"] {
  color: var(--cinnabar-tint);
  font-weight: 500;
}

.rail__foot {
  flex: 0 0 auto;
  width: 46px;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid rgba(247, 244, 236, 0.16);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.rail__meta {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: rgba(247, 244, 236, 0.42);
  max-width: none;
}

.rail__top {
  writing-mode: vertical-rl;
  text-orientation: upright;
  padding: 10px 4px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(247, 244, 236, 0.5);
  border: 1px solid rgba(247, 244, 236, 0.16);
  transition: color var(--t-fast) var(--ease),
              border-color var(--t-fast) var(--ease),
              background-color var(--t-fast) var(--ease);
}

.rail__top[data-visible] {
  color: var(--cinnabar-tint);
  border-color: rgba(241, 218, 213, 0.5);
  background: rgba(192, 54, 44, 0.22);
}

.rail__top:hover {
  color: var(--paper);
  border-color: var(--paper);
}

/* 上：索引横条 */
.topbar {
  position: fixed;
  left: var(--rail-w);
  right: 0;
  top: 0;
  z-index: 115;
  height: var(--top-h);
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 0 22px;
  background: var(--ink);
  color: var(--paper);
  border-bottom: 1px solid var(--ink-deep);
}

.brand {
  flex: 0 0 auto;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.06em;
  max-width: none;
}

.brand__link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 2px;
  color: var(--paper);
}

.brand__cn {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  line-height: 1;
  padding: 3px 5px;
  color: var(--cinnabar-tint);
  border: 1px solid rgba(241, 218, 213, 0.38);
}

.quick-index {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
}

.quick-index__item {
  position: relative;
  padding: 6px 12px;
  font-size: 14px;
  color: rgba(247, 244, 236, 0.68);
  transition: color var(--t-fast) var(--ease);
}

.quick-index__item::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 1px;
  height: 1px;
  background: var(--cinnabar);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--t-fast) var(--ease);
}

.quick-index__item:hover { color: var(--paper); }

.quick-index__item:hover::after { transform: scaleX(1); }

.topbar__tools {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.record-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 12px;
  font-size: 13px;
  color: var(--copper-tint);
  background: rgba(46, 107, 94, 0.24);
  border: 1px solid rgba(220, 231, 226, 0.3);
  transition: background-color var(--t-fast) var(--ease),
              border-color var(--t-fast) var(--ease);
}

.record-chip:hover {
  background: rgba(46, 107, 94, 0.46);
  border-color: var(--copper-tint);
}

.record-chip__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--copper-tint);
  flex: 0 0 auto;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  font-size: 13px;
  color: var(--paper);
  border: 1px solid rgba(247, 244, 236, 0.28);
  transition: border-color var(--t-fast) var(--ease);
}

.nav-toggle:hover { border-color: var(--paper); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 14px;
  height: 2px;
  background: currentColor;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 14px;
  height: 2px;
  background: currentColor;
  transition: transform var(--t-fast) var(--ease), top var(--t-fast) var(--ease);
}

.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }

.topbar__progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: var(--cinnabar);
  transform: scaleX(var(--progress, 0));
  transform-origin: left;
}

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: 72px;
  background: var(--ink);
  color: var(--paper);
  border-top: 3px solid var(--cinnabar);
}

.footer__grid {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 52px 32px 36px;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.4fr;
  gap: 32px;
  align-items: start;
}

.footer__col { min-width: 0; }

.footer__col--brand {
  padding-right: 16px;
  border-right: 1px solid rgba(247, 244, 236, 0.14);
}

.footer__brand {
  font-family: var(--font-head);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.06em;
  max-width: none;
}

.footer__tagline {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1.9;
  color: rgba(247, 244, 236, 0.48);
  max-width: 22ch;
}

.footer__title {
  padding-bottom: 9px;
  margin-bottom: 16px;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.24em;
  color: rgba(247, 244, 236, 0.45);
  border-bottom: 1px solid rgba(247, 244, 236, 0.14);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 9px;
  font-size: 14px;
}

.footer__list a {
  color: rgba(247, 244, 236, 0.76);
  transition: color var(--t-fast) var(--ease);
}

.footer__list a:hover {
  color: var(--cinnabar-tint);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.footer__list--contact li {
  font-size: 13px;
  line-height: 1.75;
  color: rgba(247, 244, 236, 0.68);
}

.footer__list--contact .mono {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: rgba(247, 244, 236, 0.88);
}

.footer__base {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 18px 32px 26px;
  border-top: 1px solid rgba(247, 244, 236, 0.14);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 26px;
  font-size: 12px;
}

.footer__meta {
  color: rgba(247, 244, 236, 0.48);
  max-width: none;
}

.footer__meta--record {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--copper-tint);
}

.footer__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--copper);
  flex: 0 0 auto;
}

.footer__meta-link {
  color: var(--copper-tint);
  border-bottom: 1px solid rgba(220, 231, 226, 0.4);
  transition: border-color var(--t-fast) var(--ease);
}

.footer__meta-link:hover { border-bottom-color: var(--copper-tint); }

.footer__meta:last-child { margin-left: auto; }

.mono {
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.04em;
}

/* ---------- 内容容器与网格 ---------- */
.container {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 32px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: var(--gap);
}

.col-1 { grid-column: span 1; }
.col-2 { grid-column: span 2; }
.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; }

.stack > * + * { margin-top: 18px; }

.hairline {
  height: 1px;
  background: var(--rule);
  border: 0;
}

.muted { color: var(--muted); }

.lead {
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
  max-width: 46ch;
}

.note {
  padding-left: 14px;
  border-left: 2px solid var(--rule);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

.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;
}

/* ---------- 标题层级 ---------- */
.display {
  font-family: var(--font-head);
  font-size: clamp(40px, 6.4vw, 72px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.page-head {
  padding: 42px 0 34px;
  border-bottom: 1px solid var(--rule);
}

.page-head__kicker {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--copper);
}

.page-head__title {
  font-family: var(--font-head);
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1.24;
  letter-spacing: -0.01em;
}

.page-head__lead {
  margin-top: 14px;
  font-size: 16px;
  color: var(--muted);
  max-width: 48ch;
}

/* ---------- 章节 ---------- */
.section {
  padding: 52px 0;
  border-top: 1px solid var(--rule);
}

.section:first-of-type { border-top: 0; }

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  margin-bottom: 28px;
}

.section__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--copper);
}

.section__title {
  font-family: var(--font-head);
  font-size: clamp(20px, 2.2vw, 28px);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.section__desc {
  width: 100%;
  font-size: 15px;
  color: var(--muted);
  max-width: 58ch;
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.breadcrumb a {
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.breadcrumb a:hover {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

.breadcrumb__sep { color: var(--rule); }

.breadcrumb [aria-current="page"] { color: var(--ink); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--ink);
  transition: background-color var(--t-fast) var(--ease),
              color var(--t-fast) var(--ease),
              border-color var(--t-fast) var(--ease),
              transform var(--t-fast) var(--ease);
}

.btn:hover {
  background: var(--ink);
  color: var(--paper);
}

.btn:active { transform: translateY(1px); }

.btn--primary {
  background: var(--cinnabar);
  border-color: var(--cinnabar);
  color: #fff;
}

.btn--primary:hover {
  background: var(--cinnabar-dark);
  border-color: var(--cinnabar-dark);
  color: #fff;
}

.btn--ghost {
  border-color: var(--rule);
  color: var(--ink);
}

.btn--ghost:hover {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.btn--copper {
  border-color: var(--copper);
  color: var(--copper);
}

.btn--copper:hover {
  background: var(--copper);
  border-color: var(--copper);
  color: #fff;
}

/* ---------- 筛选 chips ---------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 14px;
  font-size: 13px;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--rule);
  transition: color var(--t-fast) var(--ease),
              background-color var(--t-fast) var(--ease),
              border-color var(--t-fast) var(--ease);
}

.chip:hover {
  color: var(--ink);
  border-color: var(--ink);
}

.chip[aria-pressed="true"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.chip__count {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  opacity: 0.7;
}

[data-tag-item][hidden] { display: none; }

/* ---------- 标签 ---------- */
.tag {
  display: inline-block;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--muted);
  border: 1px solid var(--rule);
}

.tag--copper {
  background: var(--copper-tint);
  border-color: var(--copper-tint);
  color: var(--copper);
}

.tag--cinnabar {
  background: var(--cinnabar-tint);
  border-color: var(--cinnabar-tint);
  color: var(--cinnabar);
}

.tag--ink {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

/* ---------- 条目表 ---------- */
.ledger { border-top: 1px solid var(--rule); }

.ledger__item {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) auto;
  gap: 8px 20px;
  align-items: baseline;
  padding: 15px 12px 15px 8px;
  border-bottom: 1px solid var(--rule);
  transition: background-color var(--t-fast) var(--ease);
}

.ledger__item:hover { background: var(--cinnabar-tint); }

.ledger__no {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.ledger__title {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
}

.ledger__desc {
  margin-top: 5px;
  font-size: 14px;
  color: var(--muted);
  max-width: 60ch;
}

.ledger__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--copper);
  white-space: nowrap;
}

/* ---------- 双栏对照 ---------- */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 1px minmax(0, 1fr);
  align-items: stretch;
}

.split__col {
  padding: 0 28px;
  min-width: 0;
}

.split__col:first-child { padding-left: 0; }
.split__col:last-child { padding-right: 0; }

.split__rule { background: var(--rule); }

.split__label {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--copper);
}

/* ---------- 对照表 ---------- */
.compare__wrap {
  overflow-x: auto;
  border: 1px solid var(--rule);
}

.compare {
  width: 100%;
  font-size: 14px;
}

.compare th,
.compare td {
  padding: 11px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--rule);
}

.compare thead th {
  background: var(--ink);
  color: var(--paper);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.08em;
  border-bottom-color: var(--ink);
}

.compare tbody tr:nth-child(even) { background: var(--copper-tint); }

.compare tbody tr:last-child td { border-bottom: 0; }

.compare td:first-child {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
  white-space: nowrap;
}

/* ---------- 横向主题带 ---------- */
.band {
  display: flex;
  flex-wrap: wrap;
  background: var(--paper-2);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.band__item {
  flex: 1 1 190px;
  min-width: 0;
  padding: 18px 20px;
  border-right: 1px solid var(--rule);
}

.band__item:last-child { border-right: 0; }

.band__label {
  display: block;
  margin-bottom: 7px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--copper);
}

.band__value {
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.35;
}

/* ---------- 图片容器 ---------- */
.figure { margin: 0; }

.figure__frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: var(--paper-2);
  border: 1px solid var(--rule);
}

.figure__frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure--wide .figure__frame { aspect-ratio: 21 / 9; }
.figure--square .figure__frame { aspect-ratio: 1 / 1; }
.figure--tall .figure__frame { aspect-ratio: 4 / 5; }

.figure__placeholder {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  padding: 18px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--muted);
  background-image: repeating-linear-gradient(
    0deg,
    rgba(199, 192, 176, 0.42) 0px,
    rgba(199, 192, 176, 0.42) 1px,
    transparent 1px,
    transparent 22px
  );
}

.figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 46ch;
}

/* ---------- 滚动显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--t-slow) var(--ease), transform var(--t-slow) var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式：平板 ---------- */
@media (max-width: 1080px) {
  .quick-index { display: none; }
  .footer__grid {
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 28px;
  }
  .footer__col--brand {
    grid-column: 1 / -1;
    padding-right: 0;
    padding-bottom: 22px;
    border-right: 0;
    border-bottom: 1px solid rgba(247, 244, 236, 0.14);
  }
}

@media (max-width: 900px) {
  .split {
    grid-template-columns: minmax(0, 1fr);
  }
  .split__col {
    padding: 0 0 24px;
  }
  .split__col:last-child { padding-bottom: 0; }
  .split__rule {
    height: 1px;
    margin-bottom: 24px;
  }
}

/* ---------- 响应式：移动端外框 ---------- */
@media (max-width: 960px) {
  :root {
    --rail-w: 0px;
  }

  .skip-link { left: 0; }

  .topbar {
    left: 0;
    padding: 0 16px;
    gap: 12px;
  }

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

  .rail {
    width: 272px;
    max-width: 84vw;
    align-items: stretch;
    padding: 18px 0 16px;
    transform: translateX(-102%);
    transition: transform var(--t-mid) var(--ease);
    border-right: 1px solid var(--ink-deep);
    box-shadow: none;
    overflow-y: auto;
  }

  .rail[data-open] { transform: translateX(0); }

  .rail__mark { margin: 0 0 20px 22px; }

  .rail__nav { overflow: visible; }

  .rail__list { align-items: stretch; }

  .rail__item { justify-content: flex-start; }

  .rail__item::after {
    left: 22px;
    top: 26px;
    margin-top: 0;
  }

  .rail__link {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    width: 100%;
    padding: 13px 22px 13px 40px;
    font-size: 16px;
    letter-spacing: 0.12em;
    border-bottom: 1px solid rgba(247, 244, 236, 0.08);
  }

  .rail__foot {
    width: auto;
    margin: 22px 22px 0;
    padding-top: 16px;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
  }

  .rail__meta {
    writing-mode: horizontal-tb;
    font-size: 12px;
  }

  .rail__top {
    writing-mode: horizontal-tb;
    padding: 7px 14px;
    font-size: 12px;
  }

  .site-header::after {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 110;
    background: rgba(10, 23, 37, 0.52);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--t-mid) var(--ease);
  }

  .site-header[data-nav-open]::after {
    opacity: 1;
    pointer-events: auto;
  }

  .footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding: 40px 20px 28px;
  }

  .footer__base {
    padding: 16px 20px 24px;
    gap: 10px 18px;
  }

  .footer__meta:last-child { margin-left: 0; }

  .container { padding: 0 20px; }

  .grid { grid-template-columns: repeat(4, 1fr); }

  .col-1, .col-2, .col-3, .col-4, .col-5, .col-6, .col-7, .col-8 {
    grid-column: span 4;
  }

  .ledger__item {
    grid-template-columns: 56px minmax(0, 1fr);
  }

  .ledger__meta {
    grid-column: 2 / -1;
    white-space: normal;
  }
}

@media (max-width: 560px) {
  .footer__grid { grid-template-columns: minmax(0, 1fr); }
  .brand { font-size: 18px; }
  .record-chip { display: none; }
  .section { padding: 40px 0; }
  .page-head { padding: 30px 0 26px; }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    transition-delay: 0ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }

  .rail { transition: none; }

  .rail__item::after { transition: none; }
}