/* =========================================================
   IMTOKEN 多链资产索引 · 共享样式 /assets/site.css
   框架式导航 · 左右分屏 · 近单色 + 单一亮色
   ========================================================= */

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, h6, p, ul, ol, li, figure, figcaption, blockquote, dl, dd, table, th, td { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg, video, canvas { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 变量 ---------- */
:root {
  --c-red: #8C1F28;
  --c-red-08: rgba(140, 31, 40, .08);
  --c-red-20: rgba(140, 31, 40, .20);
  --c-turq: #1E7A8C;
  --c-turq-08: rgba(30, 122, 140, .08);
  --c-turq-16: rgba(30, 122, 140, .16);
  --c-gold: #D8A429;
  --c-mist: #F5F6F7;
  --c-white: #FFFFFF;
  --c-ink: #101216;
  --c-mute: #5A6270;
  --c-line: #E2E4E8;
  --c-deep: #0F4C57;

  --f-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", Georgia, "Times New Roman", serif;
  --f-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  --rail-w: 104px;
  --topbar-h: 52px;
  --wrap: 1200px;
  --gutter: 28px;
  --r-xl: 28px;
  --r-lg: 22px;
  --r-md: 16px;
  --r-sm: 10px;
  --pill: 999px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --dur: .22s;
}

/* ---------- 基础排版 ---------- */
body {
  font-family: var(--f-sans);
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--c-ink);
  background: var(--c-mist);
  padding-left: var(--rail-w);
  padding-top: var(--topbar-h);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--f-serif);
  font-weight: 400;
  line-height: 1.24;
  letter-spacing: .01em;
  color: var(--c-ink);
}
h1 { font-size: clamp(2rem, 5.2vw, 4rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: clamp(1.15rem, 2vw, 1.5rem); }
h4 { font-size: 1.05rem; }

p { max-width: 38em; }
strong { font-weight: 600; }
small { font-size: 12.5px; }

[id] { scroll-margin-top: calc(var(--topbar-h) + 20px); }

::selection { background: var(--c-red); color: #fff; }

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

/* ---------- 工具类 ---------- */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px; left: 10px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: var(--pill);
  background: var(--c-ink);
  color: #fff;
  font-size: 13.5px;
  letter-spacing: .04em;
  transform: translateY(-180%);
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus { transform: none; }

/* =========================================================
   头部：左侧竖向导航轨 + 顶部 1px 横框
   ========================================================= */
.site-header {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 90;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  padding: 16px 0 16px;
  background: var(--c-white);
  border-right: 1px solid var(--c-line);
}

.brand {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  padding: 6px 10px 14px;
}
.brand-mark {
  width: 40px; height: 40px;
  border-radius: 14px;
  background: var(--c-red);
  color: #fff;
  display: grid;
  place-items: center;
  transition: border-radius var(--dur) var(--ease), background var(--dur) var(--ease);
}
.brand:hover .brand-mark { border-radius: var(--pill); background: var(--c-deep); }
.brand-text {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  text-align: center;
}
.brand-lockup {
  font-family: var(--f-mono);
  font-size: 10px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .16em;
  color: var(--c-ink);
}
.brand-sub {
  font-size: 9.5px;
  line-height: 1.45;
  letter-spacing: .08em;
  color: var(--c-mute);
}

/* 顶部横框 */
.topbar {
  position: absolute;
  top: 0; left: 100%;
  width: calc(100vw - var(--rail-w));
  height: var(--topbar-h);
  z-index: 3;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 0 var(--gutter);
  background: var(--c-white);
  border-bottom: 1px solid var(--c-line);
}
.topbar-sub {
  max-width: none;
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--c-mute);
  white-space: nowrap;
}
.topbar-tools {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.quick-link {
  padding: 6px 15px;
  border: 1px solid var(--c-turq-16);
  border-radius: var(--pill);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--c-turq);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.quick-link:hover { background: var(--c-turq); border-color: var(--c-turq); color: #fff; }

.version-badge {
  padding: 6px 13px;
  border-radius: var(--pill);
  background: var(--c-red);
  color: #fff;
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .08em;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border: 1px solid var(--c-line);
  border-radius: var(--pill);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--c-mute);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.nav-toggle:hover { color: var(--c-turq); border-color: var(--c-turq-16); }
.nav-toggle-bars { position: relative; display: block; width: 16px; height: 10px; }
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute; left: 0;
  width: 16px; height: 1.5px;
  background: currentColor;
  border-radius: 2px;
  transition: transform var(--dur) var(--ease), top var(--dur) var(--ease);
}
.nav-toggle-bars::before { top: 2px; }
.nav-toggle-bars::after { top: 8px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { top: 5px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { top: 5px; transform: rotate(-45deg); }
.nav-toggle-text { line-height: 1; }

/* 竖向导航 */
.site-nav {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 10px 0;
  overflow-y: auto;
}
.nav-list {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}
.nav-item { width: 100%; display: flex; justify-content: center; }
.nav-link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: calc(var(--rail-w) - 24px);
  padding: 11px 8px;
  border-radius: var(--r-md);
  color: var(--c-mute);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.nav-link:hover { color: var(--c-turq); background: var(--c-turq-08); }
.nav-index {
  font-family: var(--f-mono);
  font-size: 10px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: .06em;
  color: #A9AFB9;
  transition: color var(--dur) var(--ease);
}
.nav-label {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 13.5px;
  line-height: 1;
  letter-spacing: .14em;
}
.nav-link::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  border-radius: 2px;
  background: var(--c-red);
  opacity: 0;
  transform: scaleY(.35);
  transform-origin: top;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.nav-link[aria-current="page"] { color: var(--c-turq); background: var(--c-turq-08); }
.nav-link[aria-current="page"] .nav-index { color: var(--c-red); }
.nav-link[aria-current="page"]::before { opacity: 1; transform: none; }
.nav-note { display: none; }

.rail-foot {
  flex: 0 0 auto;
  margin-top: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 14px 10px 0;
  border-top: 1px solid var(--c-line);
}
.rail-btn {
  width: 34px; height: 34px;
  border-radius: 50%;
  border: 1px solid var(--c-line);
  color: var(--c-mute);
  display: grid;
  place-items: center;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.rail-btn:hover { color: #fff; background: var(--c-turq); border-color: var(--c-turq); }
.rail-ver {
  padding: 4px 9px;
  border-radius: var(--pill);
  background: var(--c-ink);
  color: var(--c-gold);
  font-family: var(--f-mono);
  font-size: 10px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .08em;
}

.scroll-meter {
  position: absolute;
  top: 0; right: -1px;
  width: 2px; height: 100%;
  background: transparent;
  pointer-events: none;
  z-index: 4;
}
.scroll-meter-fill {
  display: block;
  width: 100%;
  height: 0;
  background: var(--c-red);
}

/* =========================================================
   页脚：墨黑深色分区
   ========================================================= */
.site-footer {
  margin-top: 72px;
  background: var(--c-ink);
  color: rgba(255, 255, 255, .74);
  border-top: 3px solid var(--c-red);
}
.footer-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 56px var(--gutter) 26px;
}
.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) repeat(3, minmax(0, 1fr));
  gap: 40px 32px;
  padding-bottom: 38px;
  border-bottom: 1px solid rgba(255, 255, 255, .14);
}
.footer-brand { min-width: 0; }
.footer-mark {
  font-family: var(--f-mono);
  font-size: 18px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .22em;
  color: #fff;
}
.footer-tagline {
  margin-top: 14px;
  font-size: 14px;
  letter-spacing: .04em;
  color: rgba(255, 255, 255, .8);
}
.footer-note {
  margin-top: 14px;
  max-width: 34em;
  font-size: 12.5px;
  line-height: 1.75;
  color: rgba(255, 255, 255, .46);
}
.footer-col { min-width: 0; }
.footer-col-title {
  margin-bottom: 16px;
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .16em;
  color: var(--c-gold);
}
.footer-list { display: flex; flex-direction: column; gap: 10px; }
.footer-link {
  font-size: 15px;
  color: rgba(255, 255, 255, .74);
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.footer-link:hover { color: #fff; padding-left: 6px; }
.footer-link[aria-current="page"] { color: var(--c-gold); }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 22px 32px;
  padding: 28px 0;
  border-bottom: 1px solid rgba(255, 255, 255, .14);
}
.contact-line { display: flex; flex-direction: column; gap: 7px; min-width: 0; }
.contact-key {
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .14em;
  color: rgba(255, 255, 255, .42);
}
.contact-val {
  font-size: 14.5px;
  letter-spacing: .02em;
  color: #fff;
  word-break: break-word;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-top: 22px;
  font-size: 12.5px;
  color: rgba(255, 255, 255, .5);
}
.footer-legal { max-width: none; font-family: var(--f-mono); letter-spacing: .06em; }
.footer-copy { max-width: none; }

/* =========================================================
   通用布局组件
   ========================================================= */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.page-main {
  display: block;
  background: var(--c-white);
  padding-bottom: 72px;
}
.section { padding-block: clamp(40px, 6vw, 76px); }
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px 28px;
  margin-bottom: 28px;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-mute);
}
.eyebrow::before { content: ""; width: 18px; height: 1px; background: var(--c-red); }
.lede {
  max-width: 34em;
  font-family: var(--f-serif);
  font-size: clamp(1.05rem, 1.6vw, 1.3rem);
  line-height: 1.7;
  color: var(--c-mute);
}
.rule { height: 1px; margin-block: 32px; border: 0; background: var(--c-line); }

.split {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}
.split--reverse { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.split--narrow { grid-template-columns: minmax(0, 220px) minmax(0, 1fr); }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 28px);
}

/* ---------- 卡片与标签 ---------- */
.panel {
  padding: clamp(20px, 2.4vw, 30px);
  background: var(--c-white);
  border: 1px solid var(--c-line);
  border-radius: var(--r-lg);
}
.panel--mist { background: var(--c-mist); }
.panel--deep { background: var(--c-deep); border-color: transparent; color: #fff; }
.panel--deep h2, .panel--deep h3, .panel--deep h4 { color: #fff; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border: 1px solid var(--c-line);
  border-radius: var(--pill);
  background: var(--c-white);
  font-family: var(--f-mono);
  font-size: 11.5px;
  font-weight: 500;
  line-height: 1.6;
  letter-spacing: .06em;
  color: var(--c-mute);
  white-space: nowrap;
}
.tag--turq { color: var(--c-turq); border-color: var(--c-turq-16); background: var(--c-turq-08); }
.tag--red { color: var(--c-red); border-color: var(--c-red-20); background: var(--c-red-08); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-size: 14px;
  letter-spacing: .04em;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn--solid { background: var(--c-turq); color: #fff; }
.btn--solid:hover { background: var(--c-deep); }
.btn--line { border-color: var(--c-turq); color: var(--c-turq); }
.btn--line:hover { background: var(--c-turq); color: #fff; }
.btn--ink { background: var(--c-ink); color: #fff; }
.btn--ink:hover { background: var(--c-red); }

/* ---------- 等宽数字 ---------- */
.num {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  letter-spacing: -.02em;
  color: var(--c-ink);
  white-space: nowrap;
}
.num--xl { font-size: clamp(3rem, 9vw, 6rem); line-height: .94; }
.num--lg { font-size: clamp(2rem, 5vw, 3.2rem); line-height: 1; }
.num--md { font-size: clamp(1.3rem, 2.4vw, 1.9rem); line-height: 1.1; }
.num--sm { font-size: .95rem; letter-spacing: 0; }
.num--gold { color: var(--c-gold); }

/* ---------- 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  font-weight: 500;
  line-height: 1.6;
  letter-spacing: .08em;
  color: var(--c-mute);
}
.crumbs a:hover { color: var(--c-turq); }
.crumbs-sep { color: var(--c-line); }
.crumbs [aria-current="page"] { color: var(--c-ink); }

/* ---------- 图片容器（供页面阶段放置占位图） ---------- */
.media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--c-line);
  border-radius: var(--r-lg);
  background: var(--c-mist);
}
.media img,
.media svg,
.media-fill {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--square { aspect-ratio: 1 / 1; }
.media--wide { aspect-ratio: 16 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--band { aspect-ratio: 4 / 1; border-radius: var(--r-md); }
.media--auto { aspect-ratio: auto; }
.media-frame { position: relative; }
.media-caption {
  margin-top: 10px;
  font-family: var(--f-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--c-mute);
}

/* ---------- 折叠面板 ---------- */
.fold { border-top: 1px solid var(--c-line); }
.fold:last-child { border-bottom: 1px solid var(--c-line); }
.fold-head {
  width: 100%;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 18px 4px;
  text-align: left;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.fold-head:hover { color: var(--c-turq); }
.fold-title {
  flex: 1 1 auto;
  font-family: var(--f-serif);
  font-size: 1.05rem;
  line-height: 1.55;
}
.fold-sign {
  position: relative;
  flex: 0 0 auto;
  width: 22px; height: 22px;
  margin-top: 4px;
  border: 1px solid var(--c-line);
  border-radius: 50%;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.fold-sign::before,
.fold-sign::after {
  content: "";
  position: absolute;
  left: 50%; top: 50%;
  background: var(--c-mute);
  transform: translate(-50%, -50%);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}
.fold-sign::before { width: 9px; height: 1.5px; }
.fold-sign::after { width: 1.5px; height: 9px; }
.fold[data-open="true"] .fold-head { color: var(--c-ink); box-shadow: inset 2px 0 0 var(--c-red); padding-left: 16px; }
.fold[data-open="true"] .fold-sign { border-color: var(--c-turq); background: var(--c-turq-08); }
.fold[data-open="true"] .fold-sign::before { background: var(--c-turq); }
.fold[data-open="true"] .fold-sign::after { transform: translate(-50%, -50%) scaleY(0); background: var(--c-turq); }
.fold-body { padding: 0 4px 22px; }
.fold-inner { max-width: 38em; animation: foldIn .24s var(--ease); }
@keyframes foldIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 筛选按钮组 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 14px 0;
}
.filter-btn {
  padding: 8px 16px;
  border: 1px solid var(--c-line);
  border-radius: var(--pill);
  background: var(--c-white);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--c-mute);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}
.filter-btn:hover { color: var(--c-turq); border-color: var(--c-turq-16); }
.filter-btn.is-active { background: var(--c-turq); border-color: var(--c-turq); color: #fff; }
.filter-empty { padding: 14px 0; font-size: 13px; color: var(--c-mute); }

/* =========================================================
   响应式
   ========================================================= */
@media (max-width: 1100px) and (min-width: 901px) {
  :root { --rail-w: 86px; }
  .brand-sub { font-size: 8.5px; }
  .nav-label { font-size: 12.5px; }
}

@media (max-width: 900px) {
  :root { --rail-w: 0px; --topbar-h: 56px; --gutter: 18px; }

  body {
    padding-left: 0;
    padding-top: var(--topbar-h);
    font-size: 16px;
  }

  .site-header {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: auto;
    width: 100%;
    height: var(--topbar-h);
    flex-direction: row;
    align-items: center;
    gap: 12px;
    padding: 0 var(--gutter);
    border-right: 0;
    border-bottom: 1px solid var(--c-line);
  }

  .brand {
    flex-direction: row;
    align-items: center;
    gap: 10px;
    padding: 0;
    flex: 0 0 auto;
  }
  .brand-mark { width: 30px; height: 30px; border-radius: 10px; }
  .brand-text { align-items: flex-start; text-align: left; gap: 2px; }
  .brand-lockup { font-size: 10px; }
  .brand-sub { font-size: 8.5px; letter-spacing: .06em; }

  .topbar {
    position: static;
    left: auto; top: auto;
    flex: 1 1 auto;
    width: auto;
    height: auto;
    justify-content: flex-end;
    padding: 0;
    border-bottom: 0;
    background: transparent;
  }
  .topbar-sub { display: none; }
  .topbar-tools { margin-left: auto; }
  .quick-link { display: none; }

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

  .site-nav {
    position: fixed;
    top: var(--topbar-h); left: 0; right: 0; bottom: 0;
    z-index: 5;
    flex-direction: column;
    justify-content: flex-start;
    padding: 22px var(--gutter) 44px;
    overflow-y: auto;
    background: var(--c-white);
    border-top: 1px solid var(--c-line);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-6px);
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility var(--dur);
  }
  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
  }

  .nav-list { width: 100%; align-items: stretch; gap: 0; }
  .nav-item { width: 100%; justify-content: flex-start; }
  .nav-link {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    gap: 14px;
    width: 100%;
    padding: 16px 10px 16px 18px;
    border-radius: var(--r-sm);
    border-bottom: 1px solid var(--c-line);
  }
  .nav-label {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    font-size: 17px;
    letter-spacing: .06em;
  }
  .nav-index { font-size: 11px; color: var(--c-mute); }
  .nav-link::before {
    left: 0;
    top: 50%;
    bottom: auto;
    height: 22px;
    transform: translateY(-50%) scaleY(.35);
    transform-origin: center;
  }
  .nav-link[aria-current="page"]::before { transform: translateY(-50%); }
  .nav-note {
    display: block;
    max-width: none;
    margin-top: 24px;
    font-family: var(--f-mono);
    font-size: 11.5px;
    line-height: 1.9;
    letter-spacing: .08em;
    color: var(--c-mute);
  }

  .rail-foot { display: none; }
  .scroll-meter { display: none; }

  .split,
  .split--reverse,
  .split--narrow { grid-template-columns: minmax(0, 1fr); }

  .grid { grid-template-columns: repeat(6, minmax(0, 1fr)); }

  .site-footer { margin-top: 52px; }
  .footer-inner { padding: 42px var(--gutter) 22px; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px 20px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-contact { grid-template-columns: minmax(0, 1fr); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 640px) {
  h1 { font-size: clamp(1.75rem, 8.5vw, 2.5rem); }
  .media--band { aspect-ratio: 3 / 1; }
  .btn { padding: 12px 20px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
}

/* =========================================================
   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;
  }
  .fold-inner { animation: none; }
}