/* =========================================================
   /assets/site.css — 华体移动站 · 城市坐标控制台
   共享外壳（头部 / 页脚）+ 令牌 + 内容基础组件
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--bar-h, 72px) + 16px);
}

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

ul, ol {
  padding: 0;
  list-style: none;
}

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

a {
  color: inherit;
}

[hidden] {
  display: none !important;
}

/* ---------- 2. Tokens ---------- */
:root {
  --c-deep: #0B2A4A;
  --c-deep-2: #0E3459;
  --c-ink: #07131F;
  --c-paper: #F7F4EE;
  --c-orange: #FF6A2B;
  --c-cyan: #35E0D2;
  --c-cyan-ink: #0C6E68;
  --c-grid: #8FA3B5;
  --c-slate: #4A5D6F;
  --c-warm: #D9D2C5;
  --c-green: #2E8B57;
  --c-red: #C33D2E;

  --line-dark: rgba(143, 163, 181, 0.30);
  --line-light: rgba(11, 42, 74, 0.14);
  --line-orange: rgba(255, 106, 43, 0.55);

  --rail-w: 88px;
  --bar-h: 60px;
  --gutter: clamp(18px, 4vw, 56px);
  --max: 1440px;
  --radius: 0px;

  --font-display: "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC",
    "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, serif;
  --font-body: Inter, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    system-ui, -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular,
    Menlo, Consolas, monospace;

  --ease: cubic-bezier(0.22, 0.68, 0.32, 1);
}

@media (min-width: 1024px) {
  :root { --bar-h: 72px; }
}

/* ---------- 3. 基础排版与中文阅读 ---------- */
body {
  background-color: var(--c-paper);
  background-image:
    linear-gradient(rgba(143, 163, 181, 0.10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 163, 181, 0.10) 1px, transparent 1px);
  background-size: 24px 24px;
  background-position: 0 0;
  color: var(--c-deep);
  font-family: var(--font-body);
  font-size: clamp(15px, 0.42vw + 13.6px, 17px);
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.008em;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  padding-top: var(--bar-h);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.012em;
  text-wrap: balance;
}

h1 { font-size: clamp(40px, 7vw, 88px); font-weight: 900; }
h2 { font-size: clamp(28px, 4vw, 48px); }
h3 { font-size: clamp(20px, 2.2vw, 28px); }

p { text-wrap: pretty; }

a {
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

/* 焦点环：纸白上用信号橙，深底上换荧光青 */
:focus-visible {
  outline: 2px solid var(--c-orange);
  outline-offset: 3px;
}

.site-header :focus-visible,
.site-footer :focus-visible,
.section--dark :focus-visible,
.section--ink :focus-visible {
  outline-color: var(--c-cyan);
}

/* ---------- 4. 工具类 ---------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 400;
  padding: 12px 22px;
  background: var(--c-orange);
  color: var(--c-ink);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 14px;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: top 0.18s var(--ease);
}

.skip-link:focus {
  top: 10px;
  outline: 2px solid var(--c-ink);
  outline-offset: 2px;
}

/* ---------- 5. Scroll progress ---------- */
.scroll-progress {
  position: fixed;
  top: var(--bar-h);
  left: 0;
  width: 0;
  height: 2px;
  background: var(--c-orange);
  z-index: 120;
  transition: width 0.1s linear;
  pointer-events: none;
}

/* ---------- 6. Header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--bar-h);
  z-index: 90;
  background: var(--c-deep);
  color: var(--c-paper);
  border-bottom: 1px solid rgba(143, 163, 181, 0.26);
}

/* 底部刻度尺 */
.site-header::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 5px;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(143, 163, 181, 0.55) 0 1px,
    transparent 1px 24px
  );
  opacity: 0.6;
  pointer-events: none;
  z-index: 2;
}

.header-inner {
  position: relative;
  z-index: 3;
  height: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 28px);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  min-height: 44px;
  color: var(--c-paper);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  flex: 0 0 auto;
  background: var(--c-orange);
  color: var(--c-ink);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 18px;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 11px), calc(100% - 11px) 100%, 0 100%);
  transition: transform 0.18s var(--ease);
}

.brand:hover .brand-mark {
  transform: translateY(-1px);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1.15;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.brand-line {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.18em;
  color: rgba(247, 244, 238, 0.58);
  white-space: nowrap;
}

/* 工具区 */
.header-tools {
  margin-left: auto;
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
}

/* 检索 */
.site-search {
  position: relative;
  display: flex;
  align-items: center;
  flex: 1 1 auto;
  min-width: 0;
  max-width: 320px;
  height: 40px;
  padding: 0 10px 0 32px;
  background: rgba(247, 244, 238, 0.07);
  border: 1px solid rgba(143, 163, 181, 0.42);
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease),
    box-shadow 0.18s var(--ease);
}

.site-search:focus-within {
  border-color: var(--c-cyan);
  background: rgba(53, 224, 210, 0.09);
  box-shadow: 0 0 0 1px rgba(53, 224, 210, 0.55);
}

.search-glyph {
  position: absolute;
  left: 11px;
  top: 50%;
  width: 11px;
  height: 11px;
  margin-top: -7px;
  border: 1.6px solid rgba(247, 244, 238, 0.68);
  border-radius: 50%;
  pointer-events: none;
}

.search-glyph::after {
  content: "";
  position: absolute;
  right: -5px;
  bottom: -3px;
  width: 6px;
  height: 1.6px;
  background: rgba(247, 244, 238, 0.68);
  transform: rotate(45deg);
}

.search-input {
  width: 100%;
  min-width: 0;
  height: 100%;
  border: 0;
  background: transparent;
  color: var(--c-paper);
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1;
  outline: none;
}

.search-input::placeholder {
  color: rgba(247, 244, 238, 0.48);
}

.search-input::-webkit-search-cancel-button {
  -webkit-appearance: none;
  appearance: none;
  width: 12px;
  height: 12px;
  background: var(--c-grid);
  clip-path: polygon(0 0, 100% 100%, 100% 0, 0 100%);
  cursor: pointer;
}

/* 帮助入口 */
.help-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
  height: 40px;
  padding: 0 14px;
  color: var(--c-paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.10em;
  text-decoration: none;
  border: 1px solid rgba(143, 163, 181, 0.42);
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease),
    background 0.18s var(--ease);
}

.help-link:hover {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
  background: rgba(53, 224, 210, 0.08);
}

.help-key {
  display: grid;
  place-items: center;
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
  background: var(--c-cyan);
  color: var(--c-ink);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}

/* 导航开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
  height: 40px;
  padding: 0 12px;
  background: transparent;
  color: var(--c-paper);
  border: 1px solid rgba(143, 163, 181, 0.42);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  cursor: pointer;
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.nav-toggle:hover {
  border-color: var(--c-cyan);
  background: rgba(53, 224, 210, 0.08);
}

.nav-toggle-bars {
  display: grid;
  gap: 4px;
  width: 18px;
}

.nav-toggle-bars span {
  display: block;
  height: 1.5px;
  width: 100%;
  background: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1) {
  transform: translateY(5.5px) 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(-5.5px) rotate(-45deg);
}

.nav-toggle-label {
  white-space: nowrap;
}

/* ---------- 7. 侧边轨道导航（桌面） ---------- */
.site-nav {
  position: fixed;
  top: var(--bar-h);
  bottom: 0;
  left: 0;
  width: var(--rail-w);
  z-index: 85;
  background: var(--c-ink);
  border-right: 1px solid rgba(143, 163, 181, 0.26);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 14px 0;
  overflow-y: auto;
  overscroll-behavior: contain;
}

/* 左侧刻度尺 */
.site-nav::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 7px;
  width: 5px;
  background-image: repeating-linear-gradient(
    180deg,
    rgba(143, 163, 181, 0.55) 0 1px,
    transparent 1px 16px
  );
  opacity: 0.45;
  pointer-events: none;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
  z-index: 1;
}

.nav-item {
  position: relative;
  display: flex;
  justify-content: center;
}

.nav-link {
  position: relative;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  display: block;
  padding: 14px 0;
  font-family: var(--font-display);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.12em;
  line-height: 1;
  text-align: center;
  color: rgba(247, 244, 238, 0.66);
  text-decoration: none;
  transition: color 0.16s var(--ease), background 0.16s var(--ease);
}

.nav-link:hover {
  color: var(--c-paper);
  background: rgba(247, 244, 238, 0.05);
}

.nav-link[aria-current="page"] {
  color: var(--c-orange);
  font-weight: 800;
}

.nav-link[aria-current="page"]::before {
  content: "";
  position: absolute;
  top: -7px;
  left: 50%;
  width: 6px;
  height: 6px;
  margin-left: -3px;
  background: var(--c-orange);
  transform: rotate(45deg);
}

.nav-footnote {
  display: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: rgba(143, 163, 181, 0.85);
}

/* 抽屉遮罩 */
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 70;
  background: rgba(7, 19, 31, 0.66);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.22s var(--ease), visibility 0.22s var(--ease);
}

.nav-scrim[data-open] {
  opacity: 1;
  visibility: visible;
}

/* ---------- 8. 移动 / 平板抽屉 ---------- */
@media (max-width: 1023px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    top: 0;
    bottom: 0;
    left: auto;
    right: 0;
    width: min(86vw, 340px);
    z-index: 95;
    background: var(--c-deep);
    border-right: 0;
    border-left: 1px solid rgba(143, 163, 181, 0.34);
    justify-content: flex-start;
    padding: calc(var(--bar-h) + 20px) 22px 34px;
    transform: translateX(103%);
    transition: transform 0.28s var(--ease);
    overflow-y: auto;
    box-shadow: -18px 0 40px rgba(7, 19, 31, 0.35);
  }

  .site-nav::before { display: none; }

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

  .nav-list { gap: 0; }

  .nav-item {
    display: block;
    border-bottom: 1px solid rgba(143, 163, 181, 0.22);
  }

  .nav-link {
    writing-mode: horizontal-tb;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 4px;
    font-size: 16px;
    letter-spacing: 0.03em;
    line-height: 1.4;
    text-align: left;
  }

  .nav-link[aria-current="page"] {
    padding-left: 14px;
    box-shadow: inset 3px 0 0 var(--c-orange);
    background: rgba(255, 106, 43, 0.08);
  }

  .nav-link[aria-current="page"]::before { display: none; }

  .nav-footnote {
    display: block;
    margin-top: 26px;
    padding-top: 16px;
    border-top: 1px solid rgba(143, 163, 181, 0.22);
  }

  body.nav-open { overflow: hidden; }
}

/* ---------- 9. 头部断点微调 ---------- */
@media (max-width: 767px) {
  .brand-text { display: none; }
  .help-text { display: none; }
  .help-link {
    width: 40px;
    padding: 0;
    justify-content: center;
  }
  .nav-toggle-label { display: none; }
  .nav-toggle { width: 44px; justify-content: center; padding: 0; }
  .site-search { max-width: none; }
}

@media (min-width: 768px) and (max-width: 1023px) {
  .site-search { max-width: 300px; }
}

@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }

  .site-search {
    flex: 0 0 auto;
    width: clamp(200px, 22vw, 320px);
  }

  .header-tools { flex: 0 0 auto; }
  .nav-toggle { display: none; }
  .nav-scrim { display: none; }
}

@media (min-width: 1024px) and (max-height: 820px) {
  .site-nav { justify-content: flex-start; padding-top: 28px; }
  .nav-link { font-size: 11px; letter-spacing: 0.05em; padding: 9px 0; }
}

/* ---------- 10. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(44px, 6vw, 88px);
  background: var(--c-ink);
  color: var(--c-paper);
  border-top: 1px solid rgba(143, 163, 181, 0.28);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(143, 163, 181, 0.13) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 163, 181, 0.13) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.95), transparent 82%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.95), transparent 82%);
}

.footer-grid {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(36px, 5vw, 68px) var(--gutter) clamp(26px, 3vw, 44px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 48px);
}

.footer-brand { max-width: 34ch; }

.footer-mark {
  display: block;
  width: 34px;
  height: 34px;
  margin-bottom: 16px;
  background: var(--c-orange);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 11px), calc(100% - 11px) 100%, 0 100%);
}

.footer-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  letter-spacing: 0.02em;
  line-height: 1.2;
}

.footer-tagline {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  line-height: 1.7;
  color: rgba(247, 244, 238, 0.58);
}

.footer-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  padding-bottom: 4px;
  color: var(--c-orange);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-decoration: none;
  border-bottom: 1px solid var(--line-orange);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-cta:hover {
  color: var(--c-paper);
  border-bottom-color: var(--c-paper);
}

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

.footer-col-title {
  margin-bottom: 14px;
  padding-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.20em;
  color: var(--c-cyan);
  border-bottom: 1px solid rgba(143, 163, 181, 0.30);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.footer-link {
  display: inline-block;
  padding: 6px 0;
  font-size: 14px;
  color: rgba(247, 244, 238, 0.76);
  text-decoration: none;
  transition: color 0.16s var(--ease), transform 0.16s var(--ease);
}

.footer-link:hover {
  color: var(--c-orange);
  transform: translateX(2px);
}

.footer-coord {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 16px;
  border-left: 1px solid rgba(143, 163, 181, 0.28);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  line-height: 1.7;
  color: rgba(143, 163, 181, 0.88);
}

.footer-base {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 0 auto;
  padding: 18px var(--gutter) 30px;
  border-top: 1px solid rgba(143, 163, 181, 0.22);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 26px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.03em;
  line-height: 1.7;
  color: rgba(247, 244, 238, 0.62);
}

.footer-legal { color: rgba(247, 244, 238, 0.72); }

.footer-contact { color: rgba(247, 244, 238, 0.72); }

.footer-copy { margin-left: auto; }

@media (min-width: 720px) {
  .footer-grid { grid-template-columns: 1.5fr 1fr 1fr; }
  .footer-coord { grid-column: 1 / -1; padding-left: 0; border-left: 0; }
}

@media (min-width: 1100px) {
  .footer-grid { grid-template-columns: 1.7fr 1fr 1fr 0.9fr; }
  .footer-coord { grid-column: auto; padding-left: 18px; border-left: 1px solid rgba(143, 163, 181, 0.28); }
}

/* ---------- 11. 内容容器与分区 ---------- */
.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: clamp(40px, 6vw, 88px);
}

.section--dark {
  background: var(--c-deep);
  color: var(--c-paper);
}

.section--ink {
  background: var(--c-ink);
  color: var(--c-paper);
}

.section--warm {
  background: var(--c-warm);
  color: var(--c-ink);
}

.section--gridded::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(143, 163, 181, 0.20) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 163, 181, 0.20) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 78%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 78%);
}

.section > * { position: relative; z-index: 1; }

/* 章节标题 */
.section-head {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 72ch;
  margin-bottom: clamp(24px, 3.4vw, 44px);
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.22em;
  color: var(--c-orange);
}

.section-kicker::before {
  content: "";
  width: 26px;
  height: 1px;
  flex: 0 0 auto;
  background: currentColor;
  opacity: 0.7;
}

.section-title { font-size: clamp(26px, 4vw, 44px); }

.section-sub {
  color: var(--c-slate);
  font-size: clamp(15px, 1.2vw, 17px);
  max-width: 62ch;
}

.section--dark .section-sub,
.section--ink .section-sub {
  color: rgba(247, 244, 238, 0.74);
}

.section--warm .section-sub { color: #3A4A57; }

/* 导语与长文 */
.lede {
  font-family: var(--font-serif);
  font-size: clamp(18px, 1.9vw, 22px);
  font-weight: 500;
  line-height: 1.7;
  color: var(--c-deep);
  max-width: 64ch;
}

.section--dark .lede,
.section--ink .lede { color: rgba(247, 244, 238, 0.9); }

.prose {
  max-width: 68ch;
}

.prose > * + * { margin-top: 1.1em; }

.prose h2 { margin-top: 1.9em; font-size: clamp(24px, 3vw, 32px); }
.prose h3 { margin-top: 1.6em; }
.prose ul, .prose ol { padding-left: 1.3em; list-style: disc; }
.prose ol { list-style: decimal; }
.prose a { color: var(--c-deep); text-decoration-color: var(--c-orange); }

/* 分隔与标签 */
.divider {
  height: 1px;
  border: 0;
  margin: clamp(24px, 3vw, 40px) 0;
  background: var(--line-light);
}

.section--dark .divider,
.section--ink .divider { background: rgba(143, 163, 181, 0.28); }

.coord-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--c-slate);
  text-transform: uppercase;
}

.section--dark .coord-label,
.section--ink .coord-label { color: rgba(143, 163, 181, 0.9); }

/* ---------- 12. 按钮 ---------- */
.btn {
  --btn-bg: var(--c-orange);
  --btn-fg: var(--c-ink);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: transform 0.18s var(--ease), background 0.18s var(--ease),
    color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn--primary {
  --btn-bg: var(--c-orange);
  --btn-fg: var(--c-ink);
}

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--c-paper);
  border-color: rgba(143, 163, 181, 0.55);
}

.btn--ghost:hover {
  --btn-bg: rgba(53, 224, 210, 0.10);
  --btn-fg: var(--c-cyan);
  border-color: var(--c-cyan);
}

.btn--sm {
  padding: 10px 18px;
  font-size: 13px;
}

/* ---------- 13. 标签 ---------- */
.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1.5;
  color: var(--c-slate);
  border: 1px solid currentColor;
}

.tag--orange {
  color: #C1461A;
  border-color: var(--line-orange);
}

.tag--cyan {
  color: var(--c-cyan-ink);
  border-color: rgba(53, 224, 210, 0.7);
  background: rgba(53, 224, 210, 0.16);
}

.tag--green {
  color: #1D6B41;
  border-color: rgba(46, 139, 87, 0.55);
  background: rgba(46, 139, 87, 0.12);
}

.section--dark .tag,
.section--ink .tag { color: rgba(247, 244, 238, 0.8); }

.section--dark .tag--orange,
.section--ink .tag--orange { color: var(--c-orange); }

.section--dark .tag--cyan,
.section--ink .tag--cyan { color: var(--c-cyan); }

/* ---------- 14. 面包屑 ---------- */
.breadcrumb {
  padding-top: clamp(16px, 2.4vw, 28px);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.10em;
  color: var(--c-slate);
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  color: var(--c-grid);
}

.breadcrumb-link {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.16s var(--ease), color 0.16s var(--ease);
}

.breadcrumb-link:hover {
  color: var(--c-deep);
  border-bottom-color: currentColor;
}

/* ---------- 15. 面板 / 卡片 ---------- */
.panel {
  position: relative;
  padding: clamp(18px, 2.4vw, 32px);
  background: #FFFFFF;
  border: 1px solid var(--line-light);
  color: var(--c-deep);
  transition: border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

.panel--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.panel--dark {
  background: var(--c-deep);
  border-color: rgba(143, 163, 181, 0.30);
  color: var(--c-paper);
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(16px, 2vw, 24px);
  background: var(--c-warm);
  border: 1px solid var(--line-light);
  color: var(--c-deep);
  text-decoration: none;
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease),
    background 0.18s var(--ease);
}

a.card:hover {
  transform: translateY(-2px);
  border-color: var(--c-orange);
}

.card-title {
  font-family: var(--font-display);
  font-size: clamp(17px, 1.6vw, 20px);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: 0.01em;
}

.card-text {
  font-size: 14.5px;
  line-height: 1.7;
  color: #3A4A57;
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: auto;
  padding-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-slate);
  border-top: 1px solid rgba(11, 42, 74, 0.12);
}

/* ---------- 16. 索引列表 ---------- */
.index-list {
  display: flex;
  flex-direction: column;
}

.index-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-light);
}

.index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-orange);
}

.section--dark .index-item,
.section--ink .index-item { border-bottom-color: rgba(143, 163, 181, 0.26); }

/* ---------- 17. 图像容器（可复用基础规则） ---------- */
.figure {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: linear-gradient(140deg, var(--c-deep-2), var(--c-deep) 55%, #061826 100%);
  border: 1px solid var(--line-light);
}

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

/* 蓝图网格叠层 */
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(247, 244, 238, 0.14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(247, 244, 238, 0.14) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  opacity: 0.55;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.figure-caption {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1.7;
  color: var(--c-slate);
}

.section--dark .figure-caption,
.section--ink .figure-caption { color: rgba(143, 163, 181, 0.9); }

/* ---------- 18. 网格系统 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 32px);
}

.grid--2,
.grid--3,
.grid--split {
  grid-template-columns: 1fr;
}

.grid--auto {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

@media (min-width: 640px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 760px) {
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 960px) {
  .grid--split { grid-template-columns: 7fr 5fr; align-items: start; }
}

/* 二级页：左刻度 + 右内容轨道 */
.content-track {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3vw, 48px);
  align-items: start;
}

@media (min-width: 1024px) {
  .content-track { grid-template-columns: 240px minmax(0, 1fr); }
}

.track-index {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 17px;
  border-left: 1px solid var(--line-light);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  line-height: 1.6;
}

.track-index-link {
  display: block;
  margin-left: -19px;
  padding: 7px 0 7px 17px;
  color: var(--c-slate);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease),
    background 0.16s var(--ease);
}

.track-index-link:hover {
  color: var(--c-deep);
  background: rgba(11, 42, 74, 0.05);
}

.track-index-link[aria-current="page"] {
  color: var(--c-orange);
  font-weight: 700;
  border-left-color: var(--c-orange);
}

.section--dark .track-index,
.section--ink .track-index { border-left-color: rgba(143, 163, 181, 0.3); }

.section--dark .track-index-link,
.section--ink .track-index-link { color: rgba(247, 244, 238, 0.68); }

.section--dark .track-index-link:hover,
.section--ink .track-index-link:hover { color: var(--c-paper); background: rgba(247, 244, 238, 0.06); }

/* ---------- 19. 显现动效 ---------- */
.js-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

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

/* ---------- 20. 减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

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

  .btn:hover,
  a.card:hover,
  .footer-link:hover,
  .brand:hover .brand-mark {
    transform: none;
  }
}

/* ---------- 21. 打印 ---------- */
@media print {
  .site-header,
  .site-footer,
  .scroll-progress,
  .nav-scrim,
  .skip-link { display: none !important; }

  body {
    padding: 0;
    background: #FFFFFF;
    color: #000000;
  }
}