/* ============================================================
   乐通登录 · 全站共享样式 /assets/site.css
   01 重置  02 变量与排版  03 通用组件  04 头部框架
   05 页脚    06 响应式与动效
   ============================================================ */

/* ---------- 01 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd, address { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
img, picture, svg, video { display: block; max-width: 100%; }
h1, h2, h3, h4 { line-height: 1.3; font-weight: 800; }
[hidden] { display: none !important; }

/* ---------- 02 变量与排版 ---------- */
:root {
  --silver: #EEF2F4;
  --glass: rgba(255, 255, 255, .62);
  --pine: #123B32;
  --pine-2: #1F6B58;
  --pine-deep: #0B2620;
  --gray: #C7D2D6;
  --teal: #17C3A2;
  --orange: #F26B21;
  --orange-soft: #FFE4D3;
  --ink: #101A18;
  --graphite: #55635F;
  --blue: #2F6BD8;

  --hair: rgba(199, 210, 214, .92);
  --hair-soft: rgba(199, 210, 214, .55);
  --radius: 14px;
  --radius-sm: 10px;

  --header-h: 64px;
  --rail-nav: 112px;
  --rail-meta: 52px;

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

body {
  background-color: var(--silver);
  background-image:
    radial-gradient(880px 520px at 88% -10%, rgba(23, 195, 162, .10), transparent 70%),
    linear-gradient(115deg, rgba(199, 210, 214, .45) 0 1px, transparent 1px);
  background-size: auto, 132px 132px;
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: .015em;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2 { font-family: var(--font-serif); font-weight: 900; letter-spacing: -.01em; }
h3, h4 { font-family: var(--font-sans); font-weight: 800; }

p { max-width: 68ch; }
strong, b { font-weight: 800; }
::selection { background: rgba(23, 195, 162, .28); }

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

#main-content { scroll-margin-top: calc(var(--header-h) + 16px); }

.num, .tabular { font-family: var(--font-mono); font-variant-numeric: tabular-nums; font-weight: 700; }

/* ---------- 03 通用组件 ---------- */
.wrap {
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding-inline: clamp(20px, 4vw, 64px);
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  transform: translateY(-180%);
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  background: var(--orange);
  color: var(--ink);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: .04em;
  transition: transform .16s ease;
}
.skip-link:focus { transform: translateY(0); outline: 2px solid var(--ink); outline-offset: 2px; }

.read-progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 3px;
  z-index: 100;
  background: rgba(18, 59, 50, .12);
  pointer-events: none;
}
.read-progress__bar {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--teal), #5FE7CC);
  transition: transform .12s linear;
}

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 70;
  background: rgba(11, 38, 32, .55);
  backdrop-filter: blur(2px);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .05em;
  transition: transform .16s ease, background-color .16s ease, border-color .16s ease, color .16s ease;
}
.btn--action { background: var(--orange); color: var(--ink); border-color: rgba(242, 107, 33, .95); box-shadow: 0 10px 22px -16px rgba(242, 107, 33, .95); }
.btn--action:hover { background: #FF7C33; transform: translateY(-2px); }
.btn--pine { background: var(--pine-2); color: #fff; border-color: rgba(31, 107, 88, .95); }
.btn--pine:hover { background: #26826B; transform: translateY(-2px); }
.btn--ghost { background: var(--glass); color: var(--ink); border-color: var(--hair); }
.btn--ghost:hover { border-color: var(--orange); transform: translateY(-2px); }
.btn--onDark { background: rgba(255, 255, 255, .06); color: #EAF1EF; border-color: rgba(199, 210, 214, .42); }
.btn--onDark:hover { border-color: var(--teal); transform: translateY(-2px); }
.btn--sm { padding: 8px 14px; font-size: 13px; }

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border-radius: 999px;
  border: 1px solid var(--hair);
  background: var(--glass);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--graphite);
}
.tag--action { background: var(--orange-soft); border-color: rgba(242, 107, 33, .38); color: #8A3A0C; }
.tag--pine { background: rgba(31, 107, 88, .10); border-color: rgba(31, 107, 88, .32); color: var(--pine-2); }
.tag--info { background: rgba(47, 107, 216, .10); border-color: rgba(47, 107, 216, .32); color: #1E4C9E; }

/* 文字层级 */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--pine-2);
}
.eyebrow::before { content: ""; width: 18px; height: 1px; background: currentColor; }
.lede { font-size: clamp(16px, 1.4vw, 18px); line-height: 1.85; color: var(--graphite); max-width: 66ch; }
.meta { font-size: 13px; letter-spacing: .06em; color: var(--graphite); }

/* 章节 */
.sec { position: relative; padding-block: clamp(40px, 6vw, 84px); }
.sec + .sec { border-top: 1px solid var(--hair); }
.sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 24px;
  align-items: baseline;
  margin-bottom: clamp(20px, 3vw, 36px);
}
.sec__num {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(52px, 9vw, 108px);
  line-height: .84;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: transparent;
  -webkit-text-stroke: 1px rgba(18, 59, 50, .48);
}
@supports not (-webkit-text-stroke: 1px #000) {
  .sec__num { color: rgba(18, 59, 50, .22); }
}
.sec__title { font-size: clamp(22px, 2.6vw, 32px); }
.sec__lede { grid-column: 2; font-size: 15px; line-height: 1.8; color: var(--graphite); max-width: 62ch; }

/* 栅格 */
.grid { display: grid; gap: clamp(16px, 2vw, 24px); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.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; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

/* 卡片 */
.card {
  background: #fff;
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  padding: clamp(18px, 2vw, 26px);
}
.card--glass {
  background: var(--glass);
  backdrop-filter: blur(8px);
  border-color: rgba(255, 255, 255, .72);
  box-shadow: 0 22px 44px -36px rgba(11, 38, 32, .85);
}
.card--pine {
  background: linear-gradient(160deg, #123B32, #0B2620);
  border-color: rgba(23, 195, 162, .34);
  color: #DCE6E3;
}
.card--pine .card__body { color: rgba(220, 230, 227, .78); }
.card--flat { background: transparent; border-style: dashed; }
.card__title { font-size: 17px; font-weight: 800; margin-bottom: 8px; }
.card__body { font-size: 14.5px; line-height: 1.8; color: var(--graphite); }

/* 专题研究板 */
.board {
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  background: var(--glass);
  backdrop-filter: blur(8px);
  overflow: hidden;
}
.board__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 15px 20px;
  border-bottom: 1px solid var(--hair);
  background: rgba(238, 242, 244, .72);
}
.board__title { font-size: 14px; font-weight: 800; letter-spacing: .1em; }
.board__body { padding: 4px 0; }
.board__row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 14px;
  padding: 13px 20px;
  border-top: 1px solid var(--hair-soft);
  font-size: 14px;
}
.board__row:first-child { border-top: 0; }
.board__key { font-size: 11.5px; font-weight: 700; letter-spacing: .2em; color: var(--pine-2); padding-top: 3px; }
.board__val { color: #2C3A37; line-height: 1.8; }

/* 步骤 */
.steps { display: grid; gap: 12px; }
.step {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 16px 18px;
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  background: #fff;
}
.step__num { font-family: var(--font-mono); font-size: 18px; font-weight: 800; color: var(--pine-2); font-variant-numeric: tabular-nums; }

/* 折叠 */
.acc {
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  background: #fff;
  overflow: hidden;
}
.acc + .acc { margin-top: 10px; }
.acc__trigger {
  display: flex;
  width: 100%;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  text-align: left;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}
.acc__trigger::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--pine-2);
  transition: transform .18s ease;
}
.acc__trigger[aria-expanded="true"]::after { transform: rotate(45deg); }
.acc__panel {
  padding: 14px 18px 18px;
  border-top: 1px solid var(--hair-soft);
  font-size: 14.5px;
  color: var(--graphite);
}

/* 筛选 */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
  width: fit-content;
  border: 1px solid var(--hair);
  border-radius: 999px;
  background: var(--glass);
}
.filter-btn {
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  color: var(--graphite);
  transition: background-color .16s ease, color .16s ease;
}
.filter-btn:hover { color: var(--ink); background: rgba(255, 255, 255, .8); }
.filter-btn[aria-pressed="true"] { background: var(--pine); color: #fff; }

/* 表格 */
.data-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.data-table th, .data-table td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--hair); vertical-align: top; }
.data-table th { font-size: 11.5px; letter-spacing: .16em; text-transform: uppercase; color: var(--pine-2); }
.data-table tbody tr:hover { background: rgba(255, 255, 255, .72); }

/* 时间线 */
.timeline { position: relative; display: grid; gap: 22px; padding-left: 26px; }
.timeline::before { content: ""; position: absolute; left: 6px; top: 8px; bottom: 8px; width: 1px; background: var(--hair); }
.timeline__item { position: relative; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 9px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--silver);
  border: 2px solid var(--pine-2);
}
.timeline__year { font-family: var(--font-mono); font-size: 13px; font-weight: 800; letter-spacing: .08em; color: var(--pine-2); }

/* 图像容器（页面阶段放图） */
.figure {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--hair);
  background: linear-gradient(150deg, #E6EDEF, #CBD7DB);
  isolation: isolate;
}
.figure > img, .figure > picture > img { width: 100%; height: 100%; object-fit: cover; }
.figure--21x9 { aspect-ratio: 21 / 9; }
.figure--16x9 { aspect-ratio: 16 / 9; }
.figure--3x2 { aspect-ratio: 3 / 2; }
.figure--4x3 { aspect-ratio: 4 / 3; }
.figure--1x1 { aspect-ratio: 1 / 1; }
.figure--cut { clip-path: polygon(0 0, 100% 0, 100% 86%, 0 100%); }
.figure--cut-rev { clip-path: polygon(0 0, 100% 0, 100% 100%, 0 86%); }
.figure__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 8px 14px;
  font-size: 12px;
  letter-spacing: .1em;
  color: #EAF1EF;
  background: linear-gradient(90deg, rgba(11, 38, 32, .88), rgba(11, 38, 32, .18));
  border-top-right-radius: var(--radius);
}
.figure__frame {
  position: absolute;
  inset: 10px;
  border: 1px solid rgba(255, 255, 255, .42);
  border-radius: calc(var(--radius) - 6px);
  pointer-events: none;
}
.figure--placeholder::after {
  content: "图像位";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 12px;
  letter-spacing: .3em;
  color: rgba(18, 59, 50, .38);
}

/* 面包屑 */
.breadcrumbs { padding-top: clamp(16px, 2vw, 26px); }
.crumbs { display: flex; flex-wrap: wrap; align-items: center; gap: 4px; font-size: 12.5px; letter-spacing: .04em; color: var(--graphite); }
.crumbs__item { display: inline-flex; align-items: center; }
.crumbs__item + .crumbs__item::before { content: "/"; margin-right: 6px; color: var(--hair); }
.crumbs__link { color: var(--pine-2); border-bottom: 1px solid transparent; }
.crumbs__link:hover { border-bottom-color: currentColor; }
.crumbs__item[aria-current="page"] { color: var(--ink); font-weight: 700; }

/* 显现动画 */
[data-reveal] { opacity: 0; transform: translateY(8px); transition: opacity .18s ease, transform .18s ease; }
[data-reveal].is-in { opacity: 1; transform: none; }

/* ---------- 04 头部框架 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 55;
  background: linear-gradient(118deg, #123B32 0%, #0F322A 48%, #0B2620 100%);
  color: #EAF1EF;
  border-bottom: 1px solid rgba(23, 195, 162, .32);
  transition: box-shadow .2s ease;
}
.site-header::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(42%, 460px);
  background: linear-gradient(105deg, transparent 0 42%, rgba(23, 195, 162, .12) 42% 64%, transparent 64%);
  clip-path: polygon(26% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}
.site-header.is-scrolled { box-shadow: 0 16px 32px -24px rgba(11, 38, 32, .95), 0 1px 0 rgba(23, 195, 162, .42); }
.site-header__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 26px);
  min-height: var(--header-h);
  padding: 8px clamp(16px, 2.2vw, 30px);
}

.brand { display: flex; align-items: center; gap: 12px; flex: 0 0 auto; border-radius: var(--radius-sm); }
.brand__glyph {
  position: relative;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: linear-gradient(150deg, #1F6B58, #123B32);
  border: 1px solid rgba(23, 195, 162, .55);
}
.brand__glyph::before {
  content: "";
  position: absolute;
  left: 8px;
  right: 8px;
  top: 9px;
  height: 2px;
  border-radius: 2px;
  background: var(--teal);
  box-shadow: 0 6px 0 rgba(23, 195, 162, .58), 0 12px 0 rgba(23, 195, 162, .28);
}
.brand__words { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-size: 17px; font-weight: 800; letter-spacing: .08em; color: #F3F7F6; }
.brand__tag { font-size: 11.5px; letter-spacing: .14em; color: rgba(199, 210, 214, .78); }

.header-tools { display: flex; align-items: center; gap: 10px; margin-left: auto; }

.search-hint {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 13px;
  border-radius: 999px;
  border: 1px solid rgba(199, 210, 214, .34);
  background: rgba(255, 255, 255, .07);
  color: rgba(238, 242, 244, .92);
  font-size: 13px;
  letter-spacing: .06em;
  transition: border-color .18s ease, background-color .18s ease;
}
.search-hint::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--teal); box-shadow: 0 0 0 3px rgba(23, 195, 162, .18); }
.search-hint:hover { border-color: rgba(23, 195, 162, .72); background: rgba(255, 255, 255, .13); }

.nav-toggle {
  display: none;
  position: relative;
  z-index: 90;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border-radius: 999px;
  border: 1px solid rgba(199, 210, 214, .34);
  background: rgba(255, 255, 255, .07);
  color: #EAF1EF;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .1em;
}
.nav-toggle__box { display: grid; gap: 4px; width: 16px; }
.nav-toggle__bar { height: 2px; border-radius: 2px; background: var(--teal); transition: transform .18s ease, opacity .18s ease; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 导航轨：默认 = 移动端抽屉 */
.rail--nav {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 80;
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: min(324px, 84vw);
  height: 100%;
  padding: calc(var(--header-h) + 20px) 20px 24px;
  overflow-y: auto;
  background: linear-gradient(170deg, #123B32, #0B2620);
  color: #DCE6E3;
  border-right: 1px solid rgba(23, 195, 162, .35);
  box-shadow: 26px 0 60px -34px rgba(11, 38, 32, .95);
  transform: translateX(-102%);
  visibility: hidden;
  transition: transform .22s cubic-bezier(.4, .1, .2, 1), visibility .22s linear;
}
.rail--nav[data-open] { transform: translateX(0); visibility: visible; }

.rail__caption { font-size: 11px; font-weight: 700; letter-spacing: .28em; text-transform: uppercase; color: rgba(23, 195, 162, .85); }
.rail__list { display: flex; flex-direction: column; gap: 4px; }
.rail__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: #CFDCD8;
  font-size: 14.5px;
  letter-spacing: .04em;
  transition: color .16s ease, background-color .16s ease, border-color .16s ease, transform .16s ease;
}
.rail__index { font-family: var(--font-mono); font-size: 11px; font-variant-numeric: tabular-nums; color: rgba(199, 210, 214, .5); }
.rail__link:hover { color: #fff; background: rgba(255, 255, 255, .07); border-color: rgba(23, 195, 162, .42); transform: translateX(2px); }
.rail__link[aria-current="page"] {
  color: #fff;
  font-weight: 700;
  background: rgba(23, 195, 162, .14);
  border-color: rgba(23, 195, 162, .48);
}
.rail__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 50%;
  width: 3px;
  height: 18px;
  margin-top: -9px;
  border-radius: 3px;
  background: var(--teal);
  box-shadow: 0 0 12px rgba(23, 195, 162, .85);
}
.rail__link[aria-current="page"] .rail__index { color: var(--teal); }
.rail__foot { margin-top: auto; font-family: var(--font-mono); font-size: 11px; letter-spacing: .18em; color: rgba(199, 210, 214, .55); }

.rail--meta { display: none; }

/* ---------- 05 页脚 ---------- */
.site-footer {
  position: relative;
  z-index: 40;
  margin-top: clamp(48px, 7vw, 96px);
  background: linear-gradient(180deg, #123B32 0%, #0B2620 68%);
  color: #D9E4E1;
  border-top: 1px solid rgba(23, 195, 162, .3);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: -1px 0 auto 0;
  height: 68px;
  background: linear-gradient(180deg, rgba(23, 195, 162, .12), transparent);
  clip-path: polygon(0 0, 100% 0, 100% 24%, 0 100%);
  pointer-events: none;
}
.site-footer__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3vw, 48px);
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding: clamp(40px, 5vw, 68px) clamp(20px, 4vw, 64px) clamp(24px, 3vw, 34px);
}
.site-footer__brand { display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.site-footer__name {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: .08em;
  color: #F1F6F5;
}
.site-footer__name .brand__glyph { width: 30px; height: 30px; }
.site-footer__name .brand__glyph::before { left: 7px; right: 7px; top: 8px; }
.site-footer__tag { font-size: 13px; letter-spacing: .12em; color: rgba(199, 210, 214, .76); }
.site-footer__note { font-size: 12.5px; line-height: 1.8; color: rgba(199, 210, 214, .7); max-width: 40ch; }
.site-footer__note a { color: var(--orange-soft); border-bottom: 1px solid rgba(242, 107, 33, .5); }
.site-footer__cta { margin-top: 6px; }

.foot-col__title { margin-bottom: 14px; font-size: 11.5px; font-weight: 700; letter-spacing: .24em; text-transform: uppercase; color: var(--teal); }
.foot-list { display: flex; flex-direction: column; gap: 9px; }
.foot-link { display: inline-block; padding: 2px 0; font-size: 14px; color: #CBD8D4; transition: color .16s ease, padding-left .16s ease; }
.foot-link:hover { color: #fff; padding-left: 6px; }
.foot-link--inline { padding: 0; color: var(--orange-soft); }
.foot-link--inline:hover { padding-left: 0; border-bottom: 1px solid currentColor; }

.foot-list--lib { gap: 10px; }
.lib-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 10px;
  border-left: 4px solid var(--gray);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 14px;
  color: #CBD8D4;
  transition: color .16s ease, background-color .16s ease, border-color .16s ease;
}
.lib-link:hover { color: #fff; background: rgba(255, 255, 255, .06); }
.lib-link--tool { border-left-color: var(--pine-2); }
.lib-link--scope { border-left-color: var(--blue); }
.lib-link--feedback { border-left-color: var(--orange); }

.site-footer__contact { display: grid; gap: 2px; font-style: normal; }
.contact-line {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 12px;
  padding: 8px 0;
  border-bottom: 1px solid rgba(199, 210, 214, .14);
  font-size: 13.5px;
}
.contact-line__key { font-size: 11.5px; letter-spacing: .2em; color: rgba(23, 195, 162, .9); padding-top: 3px; }
.contact-line__val { color: #E4ECEA; word-break: break-word; }

.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 26px;
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding: 18px clamp(20px, 4vw, 64px) 28px;
  border-top: 1px solid rgba(199, 210, 214, .16);
  font-size: 12.5px;
  color: rgba(199, 210, 214, .72);
}
.legal-list { display: flex; flex-wrap: wrap; gap: 6px 20px; margin-right: auto; }
.legal-link { color: rgba(224, 233, 230, .9); border-bottom: 1px solid transparent; }
.legal-link:hover { border-bottom-color: currentColor; color: #fff; }
.record { font-family: var(--font-mono); letter-spacing: .05em; color: rgba(199, 210, 214, .68); }
.copyright { font-variant-numeric: tabular-nums; }

/* ---------- 06 响应式与动效 ---------- */
@media (max-width: 900px) {
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9 { grid-column: 1 / -1; }
  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-3, .col-4 { grid-column: span 6; }
  .col-5, .col-6, .col-7, .col-8, .col-9, .col-12 { grid-column: 1 / -1; }
}

@media (max-width: 1099px) {
  .nav-toggle { display: inline-flex; }
}

@media (max-width: 760px) {
  .sec__head { grid-template-columns: minmax(0, 1fr); gap: 10px; }
  .sec__num { grid-row: auto; font-size: clamp(44px, 16vw, 72px); }
  .sec__lede { grid-column: 1; }
  .board__row { grid-template-columns: minmax(0, 1fr); gap: 4px; }
}

@media (max-width: 560px) {
  .search-hint { display: none; }
  .brand__tag { display: none; }
  .brand__name { font-size: 15.5px; }
  .site-header__inner { gap: 10px; }
  .contact-line { grid-template-columns: 44px minmax(0, 1fr); }
}

@media (max-width: 430px) {
  .header-tools .btn { display: none; }
}

@media (min-width: 760px) {
  .site-footer__inner { grid-template-columns: 1.25fr 1fr 1fr 1.5fr; }
}

@media (min-width: 1100px) {
  :root { --header-h: 72px; }
  body { padding-left: var(--rail-nav); padding-right: var(--rail-meta); }

  .site-header__inner { padding-inline: clamp(20px, 2.4vw, 34px); }

  /* 左导航轨：框架的一部分 */
  .rail--nav {
    width: var(--rail-nav);
    transform: none;
    visibility: visible;
    gap: 10px;
    padding: calc(var(--header-h) + 26px) 12px 26px;
    border-right: 1px solid rgba(199, 210, 214, .16);
    box-shadow: none;
    transition: none;
  }
  .rail__caption { padding-left: 10px; font-size: 10px; letter-spacing: .22em; }
  .rail__link { flex-direction: column; align-items: flex-start; gap: 6px; padding: 12px 10px; }
  .rail__label { font-size: 13.5px; line-height: 1.5; letter-spacing: .06em; }
  .rail__foot { padding-left: 10px; }

  /* 右侧标记轨 */
  .rail--meta {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 54;
    width: var(--rail-meta);
    padding: calc(var(--header-h) + 34px) 0 26px;
    background: linear-gradient(180deg, rgba(255, 255, 255, .62), rgba(255, 255, 255, .3));
    border-left: 1px solid var(--hair);
    backdrop-filter: blur(6px);
    color: var(--graphite);
  }
  .rail__pulse { width: 8px; height: 8px; border-radius: 50%; background: var(--teal); box-shadow: 0 0 0 4px rgba(23, 195, 162, .16); }
  .rail__axis { flex: 1 1 auto; width: 1px; background: repeating-linear-gradient(180deg, var(--hair) 0 6px, transparent 6px 12px); }
  .rail__chapter {
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: .2em;
    color: var(--pine-2);
    font-variant-numeric: tabular-nums;
  }
  .rail__readout {
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .16em;
    color: var(--graphite);
    font-variant-numeric: tabular-nums;
  }
}

html[data-nav-open], html[data-nav-open] body { overflow: hidden; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
  .read-progress__bar { transition: none; }
}