/* ============================================================
   9393网页版 · 共享样式表 /assets/site.css
   深空蓝基底 · 霓虹青路径 · 信号橙警示 · 灰紫分区
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root {
  --void: #060B18;
  --night: #0C1730;
  --structure: #17233D;
  --neon: #4FE3D0;
  --mist: #B8F3EB;
  --signal: #FF8A3D;
  --violet: #6E6A8A;
  --cold: #9AA7BD;
  --near-white: #EAF1FF;
  --paper: #F5F8FF;

  --line: rgba(154, 167, 189, 0.14);
  --line-soft: rgba(154, 167, 189, 0.08);

  --font-heading: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", -apple-system, "Segoe UI", "Helvetica Neue", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", -apple-system, "Segoe UI", "Helvetica Neue", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", "Roboto Mono", Menlo, Consolas, "Courier New", monospace;

  --fs-1: clamp(34px, 5.4vw, 56px);
  --fs-2: clamp(27px, 3.6vw, 40px);
  --fs-3: clamp(22px, 2.6vw, 28px);
  --fs-4: clamp(18px, 1.6vw, 22px);
  --fs-5: 17px;
  --fs-6: 14px;
  --fs-7: 12px;

  --max-w: 1440px;
  --gutter: 64px;
  --axis-w: 96px;

  --radius-card: 14px;
  --radius-chip: 6px;
  --radius-btn: 10px;

  --shadow-soft: 0 2px 6px rgba(3, 7, 16, 0.45);
  --shadow-lift: 0 6px 22px rgba(3, 7, 16, 0.55);
  --glow-neon: 0 0 18px rgba(79, 227, 208, 0.35);
  --glow-signal: 0 0 18px rgba(255, 138, 61, 0.3);

  --ease-path: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--near-white);
  font-family: var(--font-body);
  font-size: var(--fs-5);
  line-height: 1.75;
  font-variant-numeric: tabular-nums;
  background-color: var(--void);
  background-image:
    radial-gradient(1100px 640px at 84% -12%, rgba(79, 227, 208, 0.075), transparent 62%),
    radial-gradient(900px 560px at 2% 4%, rgba(110, 106, 138, 0.18), transparent 58%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.16;
  color: var(--near-white);
}
h1 { font-size: var(--fs-1); }
h2 { font-size: var(--fs-2); }
h3 { font-size: var(--fs-3); }
h4 { font-size: var(--fs-4); letter-spacing: -0.01em; }

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--neon); text-decoration: none; }
a:hover { color: var(--mist); }

strong, b { font-weight: 700; }

hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }

::selection { background: rgba(79, 227, 208, 0.28); color: var(--near-white); }

/* ---------- 3. 无障碍 ---------- */
:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 3px;
  border-radius: 2px;
}
:focus:not(:focus-visible) { outline: none; }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: -90px;
  left: 24px;
  z-index: 400;
  padding: 12px 20px;
  background: var(--neon);
  color: #041F1C;
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  transition: top 0.22s var(--ease-path);
}
.skip-link:focus {
  top: 16px;
  color: #041F1C;
}

/* ---------- 4. 布局原语 ---------- */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.section { padding: 88px 0; }
.section--tight { padding: 56px 0; }
.section--flush { padding: 0; }

.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

#main-content { display: block; outline: none; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  font-weight: 500;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--neon);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}
.eyebrow--warn { color: var(--signal); }
.eyebrow--mute { color: var(--violet); }

.lede {
  max-width: 62ch;
  font-size: var(--fs-4);
  line-height: 1.65;
  color: var(--cold);
}

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

/* ---------- 5. 头部 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 200;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.3s var(--ease-path),
              border-color 0.3s var(--ease-path);
}
.site-header[data-state="solid"] {
  background-color: rgba(6, 11, 24, 0.94);
  border-bottom-color: var(--line);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  backdrop-filter: saturate(140%) blur(14px);
}
.site-header[data-open="true"] {
  background-color: var(--void);
  border-bottom-color: var(--line);
}

.header-shell {
  position: relative;
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: 88px;
  display: flex;
  align-items: center;
  gap: 28px;
  transition: height 0.3s var(--ease-path);
}
.site-header[data-state="solid"] .header-shell,
.site-header[data-open="true"] .header-shell { height: 64px; }

/* 品牌 */
.brand {
  position: relative;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  color: var(--near-white);
}
.brand:hover { color: var(--near-white); }

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  color: var(--neon);
  border: 1px solid rgba(79, 227, 208, 0.42);
  background: rgba(79, 227, 208, 0.06);
  border-radius: 0;
}
.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.brand-text b {
  font-size: 15px;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.brand-text i {
  font-style: normal;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--cold);
}

/* 导航 */
.header-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.nav-link {
  position: relative;
  display: inline-block;
  padding: 8px 11px;
  border-radius: var(--radius-chip);
  font-size: var(--fs-6);
  color: var(--cold);
  transition: color 0.18s ease, background-color 0.18s ease;
}
.nav-link:hover {
  color: var(--near-white);
  background: rgba(23, 35, 61, 0.65);
}
.nav-link[aria-current="page"] { color: var(--near-white); }
.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 3px;
  height: 1px;
  background: var(--neon);
  box-shadow: 0 0 8px rgba(79, 227, 208, 0.75);
}

.nav-quick {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-left: 20px;
  border-left: 1px solid var(--line);
}

.quick-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--cold);
  background: rgba(23, 35, 61, 0.5);
  border: 1px solid var(--line);
  border-radius: var(--radius-chip);
  cursor: pointer;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}
.quick-link:hover {
  color: #041F1C;
  background: var(--neon);
  border-color: var(--neon);
}
.quick-link[data-copied="true"] {
  color: #2A1000;
  background: var(--signal);
  border-color: var(--signal);
  box-shadow: var(--glow-signal);
}

/* 移动端按钮 */
.nav-toggle {
  position: relative;
  z-index: 3;
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 9px 14px;
  background: rgba(23, 35, 61, 0.7);
  border: 1px solid var(--line);
  border-radius: var(--radius-btn);
  color: var(--near-white);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  cursor: pointer;
  transition: border-color 0.18s ease, background-color 0.18s ease;
}
.nav-toggle:hover { border-color: rgba(79, 227, 208, 0.5); }
.nav-toggle-icon {
  position: relative;
  display: block;
  width: 18px;
  height: 12px;
}
.nav-toggle-icon span {
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: currentColor;
  transition: transform 0.24s var(--ease-path), top 0.24s var(--ease-path);
}
.nav-toggle-icon span:nth-child(1) { top: 0; }
.nav-toggle-icon span:nth-child(2) { top: 10px; }
.site-header[data-open="true"] .nav-toggle-icon span:nth-child(1) { top: 5px; transform: rotate(45deg); }
.site-header[data-open="true"] .nav-toggle-icon span:nth-child(2) { top: 5px; transform: rotate(-45deg); }

/* 滚动进度线 */
.header-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 1.5px;
  background: linear-gradient(90deg, var(--neon), var(--mist));
  box-shadow: 0 0 12px rgba(79, 227, 208, 0.6);
  opacity: 0;
  transition: opacity 0.3s var(--ease-path);
}
.site-header[data-state="solid"] .header-progress { opacity: 1; }

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 120px;
  background: #08101F;
  border-top: 1px solid var(--line);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(79, 227, 208, 0.45), transparent);
}

.footer-shell {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 72px var(--gutter) 40px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1.15fr) 2fr;
  gap: 64px;
  padding-bottom: 52px;
  border-bottom: 1px solid var(--line);
}

.footer-brand .brand { margin-bottom: 20px; }
.footer-note {
  max-width: 36ch;
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.85;
  color: var(--cold);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 32px;
}
.footer-title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--violet);
}
.footer-list {
  display: flex;
  flex-direction: column;
  gap: 11px;
}
.footer-link {
  font-size: var(--fs-6);
  color: var(--cold);
  transition: color 0.18s ease;
}
.footer-link:hover { color: var(--neon); }

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px 40px;
  padding-top: 28px;
}
.footer-contact,
.footer-legal,
.footer-copy {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1.9;
  color: var(--cold);
}
.footer-contact { flex: 1 1 420px; }
.footer-legal { color: var(--violet); }
.footer-copy { color: var(--violet); }

/* ---------- 7. 通用组件 ---------- */
.panel {
  position: relative;
  padding: 24px;
  background: var(--night);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
}

.panel--glass {
  background: rgba(12, 23, 48, 0.72);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.panel--accent { border-color: rgba(79, 227, 208, 0.42); }
.panel--warn { border-color: rgba(255, 138, 61, 0.42); }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-btn);
  font-family: var(--font-body);
  font-size: var(--fs-6);
  font-weight: 500;
  line-height: 1.4;
  text-align: center;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease,
              border-color 0.18s ease, box-shadow 0.18s ease;
}
.btn--primary {
  background: var(--neon);
  color: #041F1C;
  box-shadow: 0 0 0 rgba(79, 227, 208, 0);
}
.btn--primary:hover {
  background: var(--mist);
  color: #041F1C;
  box-shadow: var(--glow-neon);
}
.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--near-white);
}
.btn--ghost:hover {
  border-color: var(--neon);
  color: var(--neon);
}
.btn--alert {
  background: transparent;
  border-color: rgba(255, 138, 61, 0.5);
  color: var(--signal);
}
.btn--alert:hover {
  background: rgba(255, 138, 61, 0.12);
  color: var(--signal);
}

/* 芯片与标签 */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: rgba(23, 35, 61, 0.55);
  border: 1px solid var(--line);
  border-radius: var(--radius-chip);
  color: var(--cold);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: color 0.18s ease, background-color 0.18s ease,
              border-color 0.18s ease;
}
.chip:hover {
  color: var(--near-white);
  border-color: rgba(79, 227, 208, 0.45);
}
.chip[aria-pressed="true"],
.chip.is-active {
  background: rgba(79, 227, 208, 0.14);
  border-color: rgba(79, 227, 208, 0.55);
  color: var(--mist);
}

.tag {
  display: inline-block;
  padding: 3px 9px;
  border-radius: var(--radius-chip);
  background: rgba(79, 227, 208, 0.12);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
}
.tag--warn {
  background: rgba(255, 138, 61, 0.14);
  color: var(--signal);
}
.tag--mute {
  background: rgba(110, 106, 138, 0.2);
  color: #B6B2CC;
}

/* 面包屑 */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--violet);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.breadcrumb li { display: inline-flex; align-items: center; }
.breadcrumb li::after {
  content: "/";
  margin-left: 8px;
  color: rgba(110, 106, 138, 0.6);
}
.breadcrumb li:last-child::after { content: ""; margin: 0; }
.breadcrumb a { color: var(--cold); }
.breadcrumb a:hover { color: var(--neon); }
.breadcrumb [aria-current="page"] { color: var(--near-white); }

/* 长文正文 */
.prose {
  max-width: 68ch;
  font-size: var(--fs-5);
  line-height: 1.8;
  color: #CEDAF0;
}
.prose h2 {
  margin: 2em 0 0.7em;
  font-size: var(--fs-3);
}
.prose h3 {
  margin: 1.6em 0 0.6em;
  font-size: var(--fs-4);
  font-weight: 700;
}
.prose p { margin: 0 0 1.5em; }
.prose ul,
.prose ol { margin: 0 0 1.5em; padding-left: 1.4em; }
.prose li { margin-bottom: 0.55em; list-style: disc; }
.prose ol li { list-style: decimal; }
.prose a {
  color: var(--mist);
  text-decoration: underline;
  text-decoration-color: rgba(79, 227, 208, 0.35);
  text-underline-offset: 3px;
}
.prose strong { color: var(--near-white); }
.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  padding: 2px 6px;
  border-radius: var(--radius-chip);
  background: rgba(23, 35, 61, 0.85);
  color: var(--mist);
}

/* 浅色阅读区 */
.reader-surface {
  padding: clamp(28px, 5vw, 64px);
  background: var(--paper);
  border-radius: var(--radius-card);
  color: #0B1424;
}
.reader-surface h2,
.reader-surface h3,
.reader-surface h4 { color: #0B1424; }
.reader-surface .prose,
.reader-surface p,
.reader-surface li { color: #26324A; }
.reader-surface .prose h2,
.reader-surface .prose h3 { color: #0B1424; }
.reader-surface .eyebrow { color: #0E7C70; }
.reader-surface .tag {
  background: rgba(14, 124, 112, 0.12);
  color: #0E6B62;
}
.reader-surface a { color: #0E6B62; }

/* 媒体占位容器 */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--night);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
}
.media-frame > img,
.media-frame > svg,
.media-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--plain { border: 0; background: transparent; }

/* 左侧路径轴 */
.path-axis {
  position: sticky;
  top: 112px;
  align-self: start;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 20px 0 8px;
  width: var(--axis-w);
}
.path-axis__label {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--violet);
}
.path-axis__rail {
  flex: 1 1 auto;
  width: 1px;
  min-height: 96px;
  background: linear-gradient(180deg, rgba(79, 227, 208, 0.5), rgba(110, 106, 138, 0.25));
}
.path-axis__dot {
  width: 9px;
  height: 9px;
  border: 1px solid var(--violet);
  background: transparent;
  border-radius: 50%;
  transition: background-color 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}
.path-axis__dot[data-active="true"],
.path-axis__dot.is-active {
  background: var(--neon);
  border-color: var(--neon);
  box-shadow: 0 0 0 4px rgba(79, 227, 208, 0.16), var(--glow-neon);
}

/* 路径布局骨架 */
.route-layout {
  display: grid;
  grid-template-columns: var(--axis-w) minmax(0, 1fr);
  gap: 40px;
  align-items: start;
}

/* ---------- 8. 动效 ---------- */
.has-js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.38s var(--ease-path) var(--reveal-delay, 0ms),
              transform 0.38s var(--ease-path) var(--reveal-delay, 0ms);
}
.has-js .reveal.is-shown {
  opacity: 1;
  transform: translateY(0);
}

.path-draw {
  stroke-dasharray: var(--path-len, 600);
  stroke-dashoffset: 0;
}
.has-js .path-draw {
  stroke-dashoffset: var(--path-len, 600);
  animation: path-trace 0.9s var(--ease-path) forwards;
}
@keyframes path-trace {
  to { stroke-dashoffset: 0; }
}

/* ---------- 9. 响应式 ---------- */
@media (max-width: 1100px) {
  :root { --gutter: 40px; }

  html { scroll-padding-top: 72px; }

  .header-shell { height: 64px; }

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

  .header-nav {
    position: fixed;
    inset: 0;
    margin: 0;
    padding: 104px var(--gutter) 48px;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    background: var(--void);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-10px);
    transition: opacity 0.24s var(--ease-path),
                transform 0.24s var(--ease-path),
                visibility 0.24s linear;
  }
  .site-header[data-open="true"] .header-nav {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .nav-link {
    display: block;
    padding: 16px 4px;
    font-size: 20px;
    border-radius: 0;
    border-bottom: 1px solid var(--line-soft);
  }
  .nav-link:hover { background: transparent; color: var(--neon); }
  .nav-link[aria-current="page"] { color: var(--neon); }
  .nav-link[aria-current="page"]::after { display: none; }

  .nav-quick {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin-top: 28px;
    padding: 28px 0 0;
    border-left: 0;
    border-top: 1px solid var(--line);
  }
  .quick-link {
    justify-content: center;
    padding: 13px 16px;
    font-size: 13px;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 44px;
  }
  .footer-nav { gap: 24px; }

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

  .route-layout {
    grid-template-columns: 48px minmax(0, 1fr);
    gap: 24px;
  }
  .path-axis { width: 48px; top: 88px; }
  .path-axis__label { font-size: 10px; letter-spacing: 0.2em; }

  .section { padding: 64px 0; }
}

@media (max-width: 720px) {
  :root { --gutter: 20px; }

  body { font-size: 16px; }

  .brand-text i { display: none; }

  .footer-shell { padding: 52px var(--gutter) 32px; }
  .footer-nav { grid-template-columns: 1fr 1fr; gap: 32px 20px; }
  .footer-base { flex-direction: column; align-items: flex-start; gap: 10px; }
  .footer-contact { flex: 1 1 auto; }

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

  .nav-toggle-label { display: none; }

  .route-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }
  .path-axis {
    position: static;
    flex-direction: row;
    width: 100%;
    padding: 0 0 20px;
    gap: 10px;
  }
  .path-axis__label {
    writing-mode: horizontal-tb;
    letter-spacing: 0.2em;
  }
  .path-axis__rail {
    width: auto;
    height: 1px;
    min-height: 0;
    flex: 1 1 auto;
    background: linear-gradient(90deg, rgba(79, 227, 208, 0.5), rgba(110, 106, 138, 0.25));
  }

  .section { padding: 52px 0; }
  .site-footer { margin-top: 72px; }
}

@media (max-width: 420px) {
  .footer-nav { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 10. 动效降级 ---------- */
@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;
  }
  .has-js .reveal {
    opacity: 1 !important;
    transform: none !important;
  }
  .has-js .path-draw {
    stroke-dashoffset: 0 !important;
    animation: none !important;
  }
  .header-progress { transition: none; }
}