/* ==========================================================================
   aurora v2.1 — Tailwind 风格 · 多色调设计系统
   骨架仍是 Tailwind：细边框 / 圆角刻度 / 系统字重 / 4px 间距
   新增：9 组色相令牌（每区块可独立着色）+ 滚动进场、hover、光斑漂移动效
   用法：给容器或组件加 .av-t-{indigo|violet|sky|cyan|teal|emerald|amber|rose|fuchsia}
        内部组件通过继承 var(--tone) 自动取色
   ========================================================================== */

/* ---------- 1. 设计令牌 ---------- */
:root {
  --slate-50: #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  --slate-950: #020617;

  --white: #ffffff;

  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --shadow-xs: 0 1px 2px 0 rgb(15 23 42 / 0.05);
  --shadow-sm: 0 1px 3px 0 rgb(15 23 42 / 0.07), 0 1px 2px -1px rgb(15 23 42 / 0.06);
  --shadow-md: 0 4px 12px -2px rgb(15 23 42 / 0.08), 0 2px 4px -2px rgb(15 23 42 / 0.05);
  --shadow-lg: 0 16px 40px -12px rgb(15 23 42 / 0.16), 0 6px 12px -6px rgb(15 23 42 / 0.07);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC",
    sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --wrap: 1160px;
  --gutter: 24px;

  /* 兜底色相，未显式指定 tone 的组件默认靛蓝 */
  --tone: #4f46e5;
  --tone-soft: #eef2ff;
  --tone-line: #c7d2fe;
  --tone-deep: #4338ca;
  --tone-glow: rgb(79 70 229 / 0.42);

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ---------- 2. 色相令牌（对齐 Tailwind 色板） ---------- */
.av-t-indigo {
  --tone: #4f46e5;
  --tone-soft: #eef2ff;
  --tone-line: #c7d2fe;
  --tone-deep: #4338ca;
  --tone-glow: rgb(79 70 229 / 0.4);
}
.av-t-violet {
  --tone: #7c3aed;
  --tone-soft: #f5f3ff;
  --tone-line: #ddd6fe;
  --tone-deep: #6d28d9;
  --tone-glow: rgb(124 58 237 / 0.4);
}
.av-t-sky {
  --tone: #0284c7;
  --tone-soft: #f0f9ff;
  --tone-line: #bae6fd;
  --tone-deep: #0369a1;
  --tone-glow: rgb(2 132 199 / 0.4);
}
.av-t-cyan {
  --tone: #0891b2;
  --tone-soft: #ecfeff;
  --tone-line: #a5f3fc;
  --tone-deep: #0e7490;
  --tone-glow: rgb(8 145 178 / 0.4);
}
.av-t-teal {
  --tone: #0d9488;
  --tone-soft: #f0fdfa;
  --tone-line: #99f6e4;
  --tone-deep: #0f766e;
  --tone-glow: rgb(13 148 136 / 0.4);
}
.av-t-emerald {
  --tone: #059669;
  --tone-soft: #ecfdf5;
  --tone-line: #a7f3d0;
  --tone-deep: #047857;
  --tone-glow: rgb(5 150 105 / 0.4);
}
.av-t-amber {
  --tone: #d97706;
  --tone-soft: #fffbeb;
  --tone-line: #fde68a;
  --tone-deep: #b45309;
  --tone-glow: rgb(217 119 6 / 0.4);
}
.av-t-rose {
  --tone: #e11d48;
  --tone-soft: #fff1f2;
  --tone-line: #fecdd3;
  --tone-deep: #be123c;
  --tone-glow: rgb(225 29 72 / 0.4);
}
.av-t-fuchsia {
  --tone: #c026d3;
  --tone-soft: #fdf4ff;
  --tone-line: #f5d0fe;
  --tone-deep: #a21caf;
  --tone-glow: rgb(192 38 211 / 0.4);
}

/* ---------- 3. 基础重置 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  interpolate-size: allow-keywords;
}

body.av-body {
  margin: 0;
  background: var(--white);
  color: var(--slate-700);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.av-body img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* :where() 把基础样式压到零特异性，避免覆盖组件类 */
:where(.av-body) a {
  color: inherit;
  text-decoration: none;
}

:where(.av-body) h1,
:where(.av-body) h2,
:where(.av-body) h3,
:where(.av-body) h4 {
  margin: 0;
  color: var(--slate-900);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

:where(.av-body) p {
  margin: 0;
}

.av-wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.av-skip {
  position: absolute;
  left: -9999px;
  top: 0;
}

.av-skip:focus {
  left: 12px;
  top: 12px;
  z-index: 99;
  padding: 8px 14px;
  background: var(--slate-900);
  color: #fff;
  border-radius: var(--radius);
}

/* ---------- 4. 顶栏 ---------- */
.av-top {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--slate-200);
  transition: box-shadow 0.3s, border-color 0.3s;
}

.av-top.is-stuck {
  border-color: transparent;
  box-shadow: 0 1px 0 0 var(--slate-200), 0 10px 30px -18px rgb(15 23 42 / 0.28);
}

.av-top-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  height: 64px;
}

.av-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--slate-900);
}

.av-logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, #4f46e5, #7c3aed 55%, #0891b2);
  color: #fff;
  flex: 0 0 auto;
  box-shadow: 0 4px 12px -4px rgb(79 70 229 / 0.6);
  transition: transform 0.4s var(--ease-spring), box-shadow 0.3s;
}

.av-logo:hover .av-logo-mark {
  transform: rotate(-8deg) scale(1.06);
  box-shadow: 0 8px 18px -6px rgb(79 70 229 / 0.7);
}

.av-logo-mark svg {
  width: 17px;
  height: 17px;
  display: block;
}

.av-logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.av-logo-name {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--slate-900);
}

.av-logo-sub {
  font-size: 11px;
  font-weight: 400;
  color: var(--slate-400);
  letter-spacing: 0.01em;
}

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

.av-nav a {
  position: relative;
  padding: 7px 11px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  color: var(--slate-600);
  transition: color 0.18s, background-color 0.18s;
}

.av-nav a::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 2px;
  height: 2px;
  border-radius: 2px;
  background: var(--indigo-500, #6366f1);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.28s var(--ease-out);
}

.av-nav a:hover {
  color: var(--slate-900);
  background: var(--slate-100);
}

.av-nav a:hover::after,
.av-nav a.is-active::after {
  transform: scaleX(1);
}

.av-nav a.is-active {
  color: var(--slate-900);
  font-weight: 600;
}

.av-top-act {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}

.av-burger {
  display: none;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  padding: 0;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--slate-700);
  cursor: pointer;
  transition: border-color 0.2s, background-color 0.2s;
}

.av-burger:hover {
  border-color: var(--indigo-200, #c7d2fe);
  background: #eef2ff;
}

.av-burger svg {
  width: 18px;
  height: 18px;
}

/* ---------- 5. 按钮 ---------- */
.av-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.2s, border-color 0.2s, color 0.2s, box-shadow 0.25s,
    transform 0.25s var(--ease-out);
}

.av-btn svg {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  transition: transform 0.28s var(--ease-spring);
}

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

.av-btn--primary {
  background: linear-gradient(135deg, #4f46e5, #6d28d9);
  color: #fff;
  box-shadow: 0 4px 14px -6px rgb(79 70 229 / 0.55), var(--shadow-xs);
}

.av-btn--primary:hover {
  background: linear-gradient(135deg, #6366f1, #7c3aed);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 14px 28px -12px rgb(99 102 241 / 0.75);
}

.av-btn--ghost {
  background: var(--white);
  border-color: var(--slate-300);
  color: var(--slate-700);
  box-shadow: var(--shadow-xs);
}

.av-btn--ghost:hover {
  border-color: var(--indigo-200, #c7d2fe);
  background: #f5f3ff;
  color: var(--slate-900);
  transform: translateY(-2px);
  box-shadow: 0 10px 22px -14px rgb(79 70 229 / 0.5);
}

.av-btn--lg {
  padding: 13px 22px;
  font-size: 15px;
}

.av-btn--light {
  background: #fff;
  color: var(--slate-900);
  box-shadow: 0 8px 24px -12px rgb(0 0 0 / 0.5);
}

.av-btn--light:hover {
  background: #f8fafc;
  color: var(--slate-950);
  transform: translateY(-2px);
  box-shadow: 0 16px 34px -14px rgb(0 0 0 / 0.6);
}

.av-btn:active {
  transform: translateY(0) scale(0.985);
}

/* ---------- 6. 徽章 / 眉题 ---------- */
.av-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px 4px 9px;
  border: 1px solid var(--tone-line);
  border-radius: var(--radius-full);
  background: var(--tone-soft);
  color: var(--tone-deep);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.01em;
  line-height: 1.6;
}

.av-badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--tone);
  flex: 0 0 auto;
  box-shadow: 0 0 0 3px var(--tone-soft);
  animation: av-pulse 2.6s ease-in-out infinite;
}

.av-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--tone);
}

.av-eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--tone);
  box-shadow: 0 0 0 3px var(--tone-soft);
  flex: 0 0 auto;
}

/* ---------- 7. 首屏 ---------- */
.av-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--slate-200);
  background: var(--white);
}

.av-hero::before {
  content: "";
  position: absolute;
  inset: -30% 35% 15% -18%;
  background: radial-gradient(closest-side, rgb(99 102 241 / 0.18), transparent 100%);
  pointer-events: none;
  animation: av-drift-a 22s ease-in-out infinite alternate;
}

.av-hero::after {
  content: "";
  position: absolute;
  inset: -18% -18% 18% 42%;
  background: radial-gradient(closest-side, rgb(8 145 178 / 0.2), transparent 100%),
    radial-gradient(closest-side at 26% 82%, rgb(192 38 211 / 0.14), transparent 100%);
  pointer-events: none;
  animation: av-drift-b 26s ease-in-out infinite alternate;
}

.av-hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
  gap: 56px;
  align-items: center;
  padding: 72px var(--gutter) 76px;
}

.av-hero-copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 20px;
  min-width: 0;
}

.av-h1 {
  font-size: clamp(30px, 3.9vw, 46px);
  font-weight: 700;
  line-height: 1.16;
  letter-spacing: -0.028em;
  color: var(--slate-900);
  max-width: 19ch;
  /* 地区名 + 关键词长度不一：balance 让两行长度接近，避免末行只剩一两个字 */
  text-wrap: balance;
}

.av-lead {
  max-width: 50ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--slate-600);
}

.av-hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 4px;
}

.av-ticks {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 6px 0 0;
  padding: 0;
  width: 100%;
  list-style: none;
}

.av-tick {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  color: var(--slate-500);
  transition: color 0.2s;
}

.av-tick:hover {
  color: var(--slate-800);
}

.av-tick svg {
  width: 15px;
  height: 15px;
  flex: 0 0 auto;
  color: var(--emerald, #059669);
}

/* ---- 首屏右侧：软件界面模拟卡 ---- */
.av-app {
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-xl);
  background: var(--white);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  min-width: 0;
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.4s var(--ease-out);
}

.av-app:hover {
  border-color: var(--indigo-200, #c7d2fe);
  transform: translateY(-4px);
  box-shadow: 0 28px 60px -24px rgb(79 70 229 / 0.35), 0 6px 14px -6px rgb(15 23 42 / 0.08);
}

.av-app-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 11px 14px;
  border-bottom: 1px solid var(--slate-200);
  background: linear-gradient(180deg, #f8fafc, #f1f5f9);
}

.av-app-dots {
  display: flex;
  gap: 5px;
  flex: 0 0 auto;
}

.av-app-dots i {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: block;
}

.av-app-dots i:nth-child(1) {
  background: #fda4af;
}

.av-app-dots i:nth-child(2) {
  background: #fcd34d;
}

.av-app-dots i:nth-child(3) {
  background: #6ee7b7;
}

.av-app-title {
  font-size: 12px;
  font-weight: 500;
  color: var(--slate-500);
  margin-left: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.av-app-tag {
  margin-left: auto;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: #ecfdf5;
  border: 1px solid #a7f3d0;
  color: #047857;
  font-size: 11px;
  font-weight: 600;
  flex: 0 0 auto;
}

.av-app-body {
  padding: 16px 14px 18px;
}

.av-app-meta {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  font-size: 12px;
  color: var(--slate-500);
  margin-bottom: 7px;
}

.av-app-meta b {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: #4f46e5;
}

.av-app-track {
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--slate-100);
  overflow: hidden;
  margin-bottom: 16px;
}

.av-app-track i {
  display: block;
  height: 100%;
  width: 68%;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, #6366f1, #7c3aed 60%, #0891b2);
  animation: av-fill 1.9s 0.45s var(--ease-out) both;
}

.av-app-list {
  display: grid;
  gap: 1px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--slate-200);
}

.av-app-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 11px;
  background: var(--white);
  font-size: 12px;
  transition: background-color 0.2s;
}

.av-app-row:hover {
  background: #f5f3ff;
}

.av-app-row svg {
  width: 14px;
  height: 14px;
  flex: 0 0 auto;
  color: var(--slate-400);
}

.av-app-name {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--slate-700);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1 1 auto;
  min-width: 0;
}

.av-app-st {
  flex: 0 0 auto;
  font-size: 10.5px;
  font-weight: 600;
  padding: 1px 7px;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  white-space: nowrap;
}

.av-app-st--ok {
  background: #ecfdf5;
  border-color: #a7f3d0;
  color: #047857;
}

.av-app-st--warn {
  background: #fffbeb;
  border-color: #fde68a;
  color: #b45309;
}

.av-app-st--na {
  background: #f8fafc;
  border-color: var(--slate-200);
  color: var(--slate-500);
}

.av-app-foot {
  margin-top: 12px;
  padding-top: 11px;
  border-top: 1px dashed var(--slate-200);
  font-size: 11.5px;
  line-height: 1.65;
  color: var(--slate-400);
}

/* ---------- 8. 数字条 ---------- */
.av-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-bottom: 1px solid var(--slate-200);
  background: var(--white);
}

.av-stat {
  position: relative;
  padding: 26px 24px;
  border-left: 1px solid var(--slate-200);
  min-width: 0;
  transition: background-color 0.28s;
}

.av-stat::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--tone);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.35s var(--ease-out);
}

.av-stat:hover::before {
  transform: scaleX(1);
}

.av-stat:first-child {
  border-left: 0;
  padding-left: 0;
}

.av-stat:hover {
  background: var(--tone-soft);
}

.av-stat b {
  display: block;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--tone);
  line-height: 1.15;
  transition: transform 0.3s var(--ease-spring);
}

.av-stat:hover b {
  transform: scale(1.06);
  transform-origin: left center;
}

.av-stat span {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  color: var(--slate-500);
}

/* ---------- 9. 区块 ---------- */
.av-sect {
  position: relative;
  padding: 76px 0;
}

.av-sect--tinted {
  background: linear-gradient(180deg, var(--tone-soft) 0%, #f8fafc 40%, #f8fafc 100%);
  border-top: 1px solid var(--slate-200);
  border-bottom: 1px solid var(--slate-200);
}

.av-sect--tinted::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--tone), var(--tone-line) 32%, transparent 72%);
  opacity: 0.85;
  pointer-events: none;
}

.av-sect--tight {
  padding: 56px 0;
}

.av-sect-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 36px;
}

.av-sect-head > div {
  min-width: 0;
}

.av-h2 {
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 700;
  letter-spacing: -0.022em;
  line-height: 1.25;
  color: var(--slate-900);
}

.av-sub {
  margin-top: 9px;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.7;
  color: var(--slate-500);
}

.av-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 14px;
  font-weight: 500;
  color: var(--tone);
  white-space: nowrap;
  transition: gap 0.25s var(--ease-out), color 0.2s;
}

.av-link:hover {
  gap: 9px;
  color: var(--tone-deep);
}

.av-link svg {
  width: 14px;
  height: 14px;
}

/* ---------- 10. 卡片栅格 ---------- */
.av-grid {
  display: grid;
  gap: 16px;
}

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

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

.av-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  min-width: 0;
  overflow: hidden;
  transition: border-color 0.28s, box-shadow 0.32s, transform 0.32s var(--ease-out);
}

.av-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 26%;
  height: 3px;
  background: linear-gradient(90deg, var(--tone), transparent);
  transition: width 0.45s var(--ease-out);
}

.av-card:hover {
  border-color: var(--tone-line);
  transform: translateY(-5px);
  box-shadow: 0 22px 40px -24px var(--tone-glow), 0 4px 10px -6px rgb(15 23 42 / 0.06);
}

.av-card:hover::after {
  width: 100%;
}

.av-card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius);
  border: 1px solid var(--tone-line);
  background: color-mix(in srgb, var(--tone) 20%, #fff);
  color: var(--tone);
  margin-bottom: 2px;
  transition: transform 0.4s var(--ease-spring), background-color 0.28s, color 0.28s,
    box-shadow 0.28s;
}

.av-card-icon svg {
  width: 19px;
  height: 19px;
}

.av-card:hover .av-card-icon {
  background: var(--tone);
  color: #fff;
  border-color: var(--tone);
  transform: rotate(-7deg) scale(1.08);
  box-shadow: 0 8px 16px -6px var(--tone-glow);
}

.av-card-h {
  font-size: 15.5px;
  font-weight: 600;
  color: var(--slate-900);
  letter-spacing: -0.008em;
  transition: color 0.25s;
}

.av-card:hover .av-card-h {
  color: var(--tone-deep);
}

.av-card-p {
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--slate-500);
}

/* ---------- 10b. 服务范围（类目卡） ---------- */
.av-cats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.av-cat {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  min-width: 0;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.28s, box-shadow 0.32s, transform 0.32s var(--ease-out);
}

.av-cat::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--tone), transparent);
  transform: scaleX(0.18);
  transform-origin: left center;
  transition: transform 0.45s var(--ease-out);
}

.av-cat:hover {
  transform: translateY(-4px);
  border-color: var(--tone-line);
  box-shadow: 0 22px 40px -26px var(--tone-glow), 0 4px 10px -6px rgb(15 23 42 / 0.06);
}

.av-cat:hover::after {
  transform: scaleX(1);
}

.av-cat-top {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.av-cat-ico {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  width: 34px;
  height: 34px;
  border-radius: var(--radius);
  border: 1px solid var(--tone-line);
  background: color-mix(in srgb, var(--tone) 18%, #fff);
  color: var(--tone);
  transition: background-color 0.28s, color 0.28s, transform 0.4s var(--ease-spring);
}

.av-cat-ico svg {
  width: 17px;
  height: 17px;
}

.av-cat:hover .av-cat-ico {
  background: var(--tone);
  color: #fff;
  border-color: var(--tone);
  transform: rotate(-6deg) scale(1.06);
}

.av-cat-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--slate-900);
  letter-spacing: -0.008em;
  min-width: 0;
  transition: color 0.25s;
}

.av-cat:hover .av-cat-name {
  color: var(--tone-deep);
}

.av-cat-n {
  margin-left: auto;
  flex: none;
  font-size: 11.5px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--tone-deep);
  background: color-mix(in srgb, var(--tone) 10%, #fff);
  border: 1px solid var(--tone-line);
  border-radius: 999px;
  padding: 1px 8px;
  white-space: nowrap;
}

.av-cat-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.av-cat-tag {
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--slate-600);
  background: var(--slate-100);
  border-radius: 5px;
  padding: 1px 7px;
  transition: background-color 0.25s, color 0.25s;
}

.av-cat:hover .av-cat-tag {
  background: color-mix(in srgb, var(--tone) 9%, #fff);
  color: var(--slate-700);
}

.av-cat-fmt {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px dashed var(--slate-200);
  font-size: 12px;
  line-height: 1.7;
  color: var(--slate-500);
}

.av-cat--lead {
  grid-column: span 2;
}

.av-cat--lead .av-cat-name {
  font-size: 16px;
}

.av-cat--wide {
  grid-column: span 2;
}

.av-cats-note {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  margin-top: 14px;
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--slate-500);
}

.av-cats-note svg {
  flex: none;
  width: 15px;
  height: 15px;
  margin-top: 2px;
  color: var(--slate-400);
}

/* ---------- 11. 流程 ---------- */
.av-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.av-step {
  position: relative;
  padding: 22px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  min-width: 0;
  transition: border-color 0.28s, box-shadow 0.32s, transform 0.32s var(--ease-out);
}

.av-step:hover {
  border-color: var(--tone-line);
  transform: translateY(-4px);
  box-shadow: 0 20px 36px -24px var(--tone-glow);
}

.av-step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-full);
  background: var(--tone);
  color: #fff;
  font-size: 12.5px;
  font-weight: 700;
  font-family: var(--font-mono);
  box-shadow: 0 6px 14px -6px var(--tone-glow);
  transition: transform 0.4s var(--ease-spring), box-shadow 0.3s;
}

.av-step:hover .av-step-num {
  transform: scale(1.12) rotate(-6deg);
  box-shadow: 0 10px 20px -6px var(--tone-glow);
}

.av-step h3 {
  margin: 14px 0 8px;
  font-size: 15px;
  font-weight: 600;
  color: var(--slate-900);
}

.av-step p {
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--slate-500);
}

.av-note {
  display: flex;
  gap: 10px;
  margin-top: 22px;
  padding: 14px 16px;
  border: 1px solid #fde68a;
  border-left-width: 3px;
  border-radius: var(--radius);
  background: #fffbeb;
  font-size: 13px;
  line-height: 1.75;
  color: #78350f;
}

.av-note svg {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  margin-top: 3px;
  color: #b45309;
}

/* ---------- 12. 表格 ---------- */
.av-table-wrap {
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--white);
  box-shadow: var(--shadow-xs);
}

.av-table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.av-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  font-size: 13.5px;
  text-align: left;
}

.av-table thead th {
  padding: 12px 18px;
  background: linear-gradient(180deg, #f8fafc, var(--tone-soft));
  border-bottom: 1px solid var(--tone-line);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--slate-600);
  white-space: nowrap;
}

.av-table tbody td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--slate-100);
  color: var(--slate-600);
  line-height: 1.7;
  vertical-align: top;
  transition: background-color 0.22s;
}

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

.av-table tbody tr:hover td {
  background: var(--tone-soft);
}

.av-table tbody tr:hover td:first-child {
  box-shadow: inset 3px 0 0 var(--tone);
}

.av-table tbody td:first-child {
  font-weight: 600;
  color: var(--slate-900);
  white-space: nowrap;
  transition: background-color 0.22s, box-shadow 0.22s, color 0.22s;
}

.av-table tbody tr:hover td:first-child {
  color: var(--tone-deep);
}

.av-td-dim {
  color: var(--slate-400);
}

.av-td-warn {
  color: #b45309;
}

/* ---------- 13. 文章卡 ---------- */
.av-post {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 24px 22px 22px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  min-width: 0;
  overflow: hidden;
  transition: border-color 0.28s, box-shadow 0.32s, transform 0.32s var(--ease-out);
}

.av-post::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--tone), var(--tone-line));
  opacity: 0.45;
  transition: opacity 0.35s;
}

.av-post:hover {
  border-color: var(--tone-line);
  transform: translateY(-5px);
  box-shadow: 0 22px 40px -24px var(--tone-glow);
}

.av-post:hover::before {
  opacity: 1;
}

.av-post-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--slate-400);
}

.av-post-meta i {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--slate-300);
  display: block;
}

.av-post-meta .av-tag {
  padding: 1px 8px;
  border-radius: var(--radius-full);
  background: var(--tone-soft);
  color: var(--tone-deep);
  font-weight: 500;
  font-size: 11.5px;
}

.av-post h3 {
  margin: 10px 0 8px;
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.5;
  letter-spacing: -0.008em;
}

.av-post h3 a {
  color: var(--slate-900);
  transition: color 0.2s;
}

.av-post:hover h3 a {
  color: var(--tone-deep);
}

.av-post p {
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--slate-500);
  flex: 1 1 auto;
}

.av-post-more {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--tone);
  transition: gap 0.25s var(--ease-out);
}

.av-post:hover .av-post-more {
  gap: 8px;
}

.av-post-more svg {
  width: 13px;
  height: 13px;
}

/* ---------- 14. FAQ ---------- */
.av-faq-layout {
  display: grid;
  grid-template-columns: minmax(0, 320px) minmax(0, 1fr);
  gap: 56px;
  align-items: start;
}

.av-faq-aside .av-sub {
  margin-top: 10px;
}

.av-faq-tip {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--slate-200);
  font-size: 13px;
  line-height: 1.8;
  color: var(--slate-500);
}

.av-faq-tip a {
  color: var(--tone);
  font-weight: 500;
}

.av-faq-tip a:hover {
  color: var(--tone-deep);
  text-decoration: underline;
}

.av-faq-touch {
  display: flex;
  flex-direction: column;
  gap: 9px;
  margin-top: 22px;
  padding: 16px 18px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--slate-50);
}

.av-faq-touch-row {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 13px;
  line-height: 1.6;
}

.av-faq-touch-k {
  flex: none;
  width: 60px;
  font-size: 12px;
  color: var(--slate-400);
}

.av-faq-touch-row a {
  color: var(--slate-700);
  font-weight: 500;
  transition: color 0.2s;
}

.av-faq-touch-row a:hover {
  color: var(--tone);
  text-decoration: underline;
}

.av-faq {
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  overflow: hidden;
  min-width: 0;
}

.av-faq details {
  border-bottom: 1px solid var(--slate-100);
  transition: background-color 0.25s;
}

.av-faq details:last-child {
  border-bottom: 0;
}

.av-faq summary {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px 16px 22px;
  cursor: pointer;
  list-style: none;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--slate-900);
  transition: background-color 0.22s, color 0.22s, padding-left 0.28s var(--ease-out);
}

.av-faq summary::-webkit-details-marker {
  display: none;
}

.av-faq summary::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 12px;
  width: 3px;
  border-radius: 0 2px 2px 0;
  background: var(--tone);
  transform: scaleY(0);
  transform-origin: center;
  transition: transform 0.3s var(--ease-out);
}

.av-faq details[open] > summary::before,
.av-faq summary:hover::before {
  transform: scaleY(1);
}

.av-faq summary:hover {
  background: var(--tone-soft);
  color: var(--tone-deep);
  padding-left: 26px;
}

.av-faq summary::after {
  content: "";
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  margin-right: 3px;
  border-right: 1.6px solid var(--slate-400);
  border-bottom: 1.6px solid var(--slate-400);
  transform: rotate(45deg) translateY(-2px);
  transition: transform 0.3s var(--ease-out), border-color 0.25s;
}

.av-faq details[open] summary::after {
  transform: rotate(-135deg) translateY(-2px);
  border-color: var(--tone);
}

.av-faq details[open] > summary {
  background: var(--tone-soft);
  color: var(--tone-deep);
}

.av-faq-a {
  padding: 0 20px 18px 26px;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--slate-600);
  background: var(--tone-soft);
}

/* 平滑展开（Chrome 129+，不支持的浏览器瞬时开合） */
.av-faq details::details-content {
  block-size: 0;
  overflow: clip;
  transition: block-size 0.32s var(--ease-out), content-visibility 0.32s allow-discrete;
}

.av-faq details[open]::details-content {
  block-size: auto;
}

/* ---------- 15. 下载 CTA ---------- */
.av-cta {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, #0a1124 0%, #121c34 55%, #0b1a2b 100%);
  padding: 44px 44px;
}

.av-cta::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(closest-side at 10% 8%, rgb(99 102 241 / 0.8), transparent 100%),
    radial-gradient(closest-side at 88% 96%, rgb(8 145 178 / 0.68), transparent 100%),
    radial-gradient(closest-side at 66% -18%, rgb(192 38 211 / 0.55), transparent 100%),
    radial-gradient(closest-side at 26% 128%, rgb(13 148 136 / 0.5), transparent 100%),
    radial-gradient(closest-side at 46% 54%, rgb(79 70 229 / 0.32), transparent 100%);
  pointer-events: none;
  animation: av-drift-c 20s ease-in-out infinite alternate;
}

.av-cta-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 36px;
  align-items: center;
}

.av-cta h2 {
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(92deg, #ffffff 15%, #c7d2fe 70%, #a5f3fc 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.av-cta p {
  margin-top: 10px;
  max-width: 680px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(226, 232, 240, 0.76);
  text-wrap: pretty;
}

/* 下载卡片里的补注：比正文更小更淡，避免与正文连成一大段 */
.av-cta .av-cta-note {
  margin-top: 8px;
  font-size: 12.5px;
  line-height: 1.7;
  color: rgba(226, 232, 240, 0.52);
}

.av-cta-side {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  flex: 0 0 auto;
}

.av-code {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: rgba(226, 232, 240, 0.72);
}

.av-code b {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: #fff;
  padding: 3px 9px;
  border-radius: 6px;
  background: rgb(255 255 255 / 0.14);
  border: 1px solid rgb(255 255 255 / 0.2);
  transition: background-color 0.2s, border-color 0.2s;
}

.av-code:hover b {
  background: rgb(255 255 255 / 0.24);
  border-color: rgb(255 255 255 / 0.36);
}

/* ---------- 16. 页脚 ---------- */
.av-footer {
  background: var(--slate-50);
  border-top: 1px solid var(--slate-200);
  padding: 56px 0 28px;
  font-size: 13px;
}

.av-foot-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 1fr));
  gap: 36px 28px;
}

.av-foot-brand .av-logo {
  margin-bottom: 14px;
}

.av-foot-brand p {
  font-size: 13px;
  line-height: 1.8;
  color: var(--slate-500);
  max-width: 34ch;
}

.av-foot-fact {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--slate-500);
}

.av-foot-col h4 {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--slate-400);
}

.av-foot-col h4::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--tone);
  flex: 0 0 auto;
}

.av-foot-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 9px;
}

.av-foot-col a,
.av-foot-col span {
  font-size: 13px;
  color: var(--slate-600);
  line-height: 1.6;
}

.av-foot-col a {
  transition: color 0.2s, padding-left 0.25s var(--ease-out);
}

.av-foot-col a:hover {
  color: var(--tone);
  padding-left: 4px;
}

.av-sites {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
  margin-top: 40px;
  padding-top: 28px;
  border-top: 1px solid var(--slate-200);
}

.av-sites h4 {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--slate-400);
}

.av-sites h4::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--tone);
}

.av-site-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.av-site-chip {
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 9px 12px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  min-width: 0;
  transition: border-color 0.24s, box-shadow 0.28s, transform 0.28s var(--ease-out),
    background-color 0.24s;
}

.av-site-chip:hover {
  border-color: var(--tone-line);
  background: var(--tone-soft);
  transform: translateY(-2px);
  box-shadow: 0 10px 20px -14px var(--tone-glow);
}

.av-site-chip strong {
  font-size: 12.5px;
  font-weight: 500;
  line-height: 1.45;
  color: var(--slate-700);
  overflow-wrap: anywhere;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: color 0.2s;
}

.av-site-chip:hover strong {
  color: var(--tone-deep);
}

.av-site-chip em {
  font-style: normal;
  font-size: 11px;
  color: var(--slate-400);
}

.av-foot-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 18px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--slate-200);
  font-size: 12.5px;
  color: var(--slate-500);
}

.av-foot-meta .av-sep {
  color: var(--slate-300);
}

.av-foot-meta a {
  transition: color 0.2s, text-decoration-color 0.2s;
}

.av-foot-meta a:hover {
  color: #4f46e5;
}

/* 备案号外链：平时点线提示可点，hover 变实线 */
.av-foot-meta .av-icp {
  text-decoration: underline;
  text-decoration-style: dotted;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: var(--slate-300);
}

.av-foot-meta .av-icp:hover {
  text-decoration-style: solid;
  text-decoration-color: currentColor;
}

.av-disc {
  margin-top: 14px;
  font-size: 11.5px;
  line-height: 1.9;
  color: var(--slate-400);
  max-width: 100ch;
}

/* ---------- 17. 关键帧 ---------- */
@keyframes av-pulse {
  0%,
  100% {
    box-shadow: 0 0 0 3px var(--tone-soft);
  }
  50% {
    box-shadow: 0 0 0 5px var(--tone-soft);
  }
}

@keyframes av-drift-a {
  from {
    transform: translate3d(0, 0, 0) scale(1);
  }
  to {
    transform: translate3d(6%, 8%, 0) scale(1.16);
  }
}

@keyframes av-drift-b {
  from {
    transform: translate3d(0, 0, 0) scale(1.04);
  }
  to {
    transform: translate3d(-7%, 5%, 0) scale(1.18);
  }
}

@keyframes av-drift-c {
  from {
    transform: translate3d(0, 0, 0) scale(1);
    opacity: 0.9;
  }
  to {
    transform: translate3d(3%, -4%, 0) scale(1.12);
    opacity: 1;
  }
}

@keyframes av-fill {
  from {
    width: 4%;
  }
  to {
    width: 68%;
  }
}

@keyframes av-reveal-in {
  from {
    opacity: 0;
    translate: 0 30px;
    scale: 0.98;
  }
  to {
    opacity: 1;
    translate: 0 0;
    scale: 1;
  }
}

@keyframes av-rise {
  from {
    opacity: 0;
    translate: 0 24px;
  }
  to {
    opacity: 1;
    translate: 0 0;
  }
}

/* 首屏入场：加载即播放，逐级错位 */
@media (prefers-reduced-motion: no-preference) {
  .av-hero-copy > * {
    animation: av-rise 0.78s var(--ease-out) both;
  }
  .av-hero-copy > *:nth-child(1) {
    animation-delay: 0.04s;
  }
  .av-hero-copy > *:nth-child(2) {
    animation-delay: 0.11s;
  }
  .av-hero-copy > *:nth-child(3) {
    animation-delay: 0.18s;
  }
  .av-hero-copy > *:nth-child(4) {
    animation-delay: 0.25s;
  }
  .av-hero-copy > *:nth-child(5) {
    animation-delay: 0.32s;
  }
  .av-app {
    animation: av-rise 1s 0.22s var(--ease-out) both;
  }
  .av-stats {
    animation: av-rise 0.7s 0.5s var(--ease-out) both;
  }
}

/* 滚动进场：基于 CSS 滚动驱动动画，零 JS、无 FOUC 风险 */
@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .av-reveal {
      animation: av-reveal-in linear both;
      animation-timeline: view();
      animation-range: entry 0% cover 30%;
    }
  }
}

/* ---------- 18. 响应式 ---------- */
@media (max-width: 1024px) {
  .av-nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    margin: 0;
    padding: 10px var(--gutter) 16px;
    background: #fff;
    border-bottom: 1px solid var(--slate-200);
    box-shadow: var(--shadow-md);
    display: none;
  }

  .av-nav.is-open {
    display: flex;
  }

  .av-nav a {
    padding: 11px 12px;
    font-size: 15px;
  }

  .av-nav a::after {
    display: none;
  }

  .av-burger {
    display: inline-flex;
  }

  .av-top-act {
    margin-left: auto;
  }

  .av-hero-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 40px;
    padding: 56px var(--gutter) 60px;
  }

  .av-h1 {
    max-width: 24ch;
  }

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

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

  .av-cat--lead {
    grid-column: span 2;
  }

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

  .av-stat {
    padding: 20px;
    border-left: 0;
    border-top: 1px solid var(--slate-200);
  }

  .av-stat:nth-child(odd) {
    border-right: 1px solid var(--slate-200);
    padding-left: 0;
  }

  .av-stat:nth-child(even) {
    padding-left: 20px;
  }

  .av-stat:nth-child(1),
  .av-stat:nth-child(2) {
    border-top: 0;
  }

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

  .av-faq-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

  .av-cta-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }
}

@media (max-width: 768px) {
  :root {
    --gutter: 18px;
  }

  .av-top-act .av-btn {
    display: none;
  }

  .av-sect {
    padding: 52px 0;
  }

  .av-sect--tight {
    padding: 44px 0;
  }

  .av-sect-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 26px;
  }

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

  .av-cat--lead,
  .av-cat--wide {
    grid-column: span 1;
  }

  .av-cat {
    padding: 18px;
  }

  .av-cat-fmt {
    padding-top: 9px;
  }

  .av-hero-grid {
    padding: 40px var(--gutter) 44px;
  }

  .av-hero-copy {
    gap: 16px;
  }

  .av-h1 {
    font-size: clamp(26px, 7.6vw, 34px);
    max-width: none;
  }

  .av-lead {
    font-size: 15px;
    line-height: 1.75;
  }

  .av-hero-cta .av-btn {
    flex: 1 1 100%;
  }

  .av-ticks {
    gap: 8px 14px;
  }

  .av-cta {
    padding: 28px 22px;
    border-radius: var(--radius-lg);
  }

  .av-cta-side,
  .av-cta-side .av-btn {
    width: 100%;
    align-items: stretch;
  }

  .av-foot-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .av-foot-brand {
    padding-bottom: 24px;
  }

  .av-foot-col {
    padding: 20px 0;
    border-top: 1px solid var(--slate-200);
  }

  .av-foot-col ul {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 16px;
  }

  .av-sites {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
  }

  .av-site-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .av-footer {
    padding: 40px 0 24px;
  }

  .av-foot-meta {
    gap: 6px 14px;
  }

  .av-foot-meta .av-sep {
    display: none;
  }

  .av-disc {
    margin-top: 10px;
  }

  .av-table {
    min-width: 0;
  }

  /* 窄屏把表格降级为卡片堆叠，避免横向滑动丢列 */
  .av-table thead {
    display: none;
  }

  .av-table,
  .av-table tbody,
  .av-table tr,
  .av-table td {
    display: block;
    width: 100%;
  }

  .av-table tbody tr {
    padding: 16px 18px;
    border-bottom: 1px solid var(--slate-200);
  }

  .av-table tbody tr:last-child {
    border-bottom: 0;
  }

  .av-table tbody td {
    border: 0;
    padding: 0;
    margin-top: 10px;
    font-size: 13.5px;
    line-height: 1.7;
  }

  .av-table tbody td:first-child {
    margin-top: 0;
    padding-bottom: 10px;
    border-bottom: 1px dashed var(--slate-200);
    font-size: 15px;
  }

  .av-table tbody td::before {
    content: attr(data-label);
    display: block;
    margin-bottom: 1px;
    font-size: 10.5px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--slate-400);
  }

  .av-table tbody td:first-child::before {
    display: none;
  }

  .av-table tbody tr:hover td {
    background: transparent;
  }

  .av-table tbody tr:hover td:first-child {
    box-shadow: none;
  }

  .av-app-body {
    padding: 14px 12px 16px;
  }
}

@media (max-width: 420px) {
  .av-stat {
    padding-top: 15px;
    padding-bottom: 15px;
  }

  .av-site-list {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* 动效降级：尊重系统设置 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- 20. 文章抽样：环状抽取 3 篇 ---------- */
/* 默认（无 JS / 服务端渲染）显示前 3 张；JS 抽样成功后只显示被抽中的 3 张 */
[data-post-pool] > .av-post {
  display: none;
}

[data-post-pool] > .av-post:nth-child(-n + 3) {
  display: flex;
}

[data-post-pool].is-sampled > .av-post {
  display: none;
}

[data-post-pool].is-sampled > .av-post.is-picked {
  display: flex;
}

.av-demo-note {
  display: block;
  margin-top: 7px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--slate-400);
}

/* 页脚站群标题的补充说明，消除「相关服务」指向外地的歧义 */
.av-foot-hint {
  margin-left: 8px;
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0;
  color: var(--slate-400);
  opacity: 0.85;
}

/* ==========================================================================
   21. 内页（category / content / page / 404）
   首页之外的页面共用一套「页头 + 主栏 + 侧栏」结构
   ========================================================================== */

/* ---------- 21.1 内页头 ---------- */
.av-page-head {
  position: relative;
  padding: 44px 0 36px;
  border-bottom: 1px solid var(--slate-200);
  background: linear-gradient(180deg, var(--tone-soft), transparent 78%);
  overflow: hidden;
}

.av-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  font-size: 13px;
  color: var(--slate-500);
}

.av-crumb a {
  color: var(--slate-600);
  transition: color 0.2s;
}

.av-crumb a:hover {
  color: var(--tone);
}

.av-crumb i {
  font-style: normal;
  color: var(--slate-300);
}

.av-page-head h1 {
  margin: 0 0 12px;
  font-size: clamp(26px, 3.4vw, 38px);
  line-height: 1.28;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--slate-900);
  text-wrap: balance;
}

.av-page-head .av-sub {
  max-width: 68ch;
  margin: 0;
}

.av-page-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  margin-top: 18px;
  font-size: 13px;
  color: var(--slate-500);
}

.av-page-meta b {
  font-weight: 600;
  color: var(--slate-700);
}

/* ---------- 21.2 两栏布局 ---------- */
.av-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 44px;
  align-items: start;
  padding: 44px 0 72px;
}

.av-layout--narrow {
  grid-template-columns: minmax(0, 1fr);
  max-width: 820px;
  margin: 0 auto;
}

/* ---------- 21.3 栏目列表 ---------- */
.av-list {
  display: grid;
  gap: 14px;
}

.av-li {
  position: relative;
  display: grid;
  gap: 8px;
  padding: 24px 24px 22px 26px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  overflow: hidden;
  transition: border-color 0.28s, box-shadow 0.3s var(--ease-out), transform 0.3s var(--ease-out);
}

.av-li::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--tone);
  opacity: 0;
  transition: opacity 0.28s;
}

.av-li:hover {
  border-color: var(--tone-line);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.av-li:hover::before {
  opacity: 1;
}

.av-li-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: var(--slate-400);
}

.av-li-meta i {
  font-style: normal;
  color: var(--slate-300);
}

.av-li h2 {
  margin: 0;
  font-size: 19px;
  line-height: 1.45;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.av-li h2 a {
  color: var(--slate-900);
  transition: color 0.2s;
}

.av-li h2 a:hover {
  color: var(--tone);
}

.av-li p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--slate-600);
}

.av-li-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 4px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--tone);
  transition: gap 0.24s var(--ease-out);
}

.av-li-more:hover {
  gap: 10px;
}

.av-li-more svg {
  width: 15px;
  height: 15px;
}

/* ---------- 21.4 分页 ---------- */
.av-pager {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: 40px;
  padding-top: 28px;
  border-top: 1px solid var(--slate-200);
}

.av-pager a,
.av-pager span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 38px;
  height: 38px;
  padding: 0 12px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--white);
  font-size: 13.5px;
  font-weight: 500;
  color: var(--slate-600);
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}

.av-pager a:hover {
  border-color: var(--tone-line);
  color: var(--tone);
}

.av-pager .is-current {
  border-color: var(--tone);
  background: var(--tone);
  color: #fff;
  font-weight: 600;
}

.av-pager .is-gap {
  border-color: transparent;
  background: transparent;
  min-width: 24px;
  padding: 0;
  color: var(--slate-400);
}

.av-pager-meta {
  margin-left: auto;
  font-size: 13px;
  color: var(--slate-400);
}

/* ---------- 21.5 正文排版 ---------- */
.av-prose {
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--slate-700);
  overflow-wrap: break-word;
}

.av-prose > *:first-child {
  margin-top: 0;
}

.av-prose h2 {
  margin: 2.1em 0 0.7em;
  padding-left: 14px;
  border-left: 3px solid var(--tone);
  font-size: 22px;
  line-height: 1.45;
  font-weight: 650;
  letter-spacing: -0.01em;
  color: var(--slate-900);
}

.av-prose h3 {
  margin: 1.8em 0 0.6em;
  font-size: 18px;
  line-height: 1.5;
  font-weight: 650;
  color: var(--slate-900);
}

.av-prose h4 {
  margin: 1.5em 0 0.5em;
  font-size: 16px;
  font-weight: 650;
  color: var(--slate-800);
}

.av-prose p {
  margin: 0 0 1.15em;
}

.av-prose ul,
.av-prose ol {
  margin: 0 0 1.15em;
  padding-left: 1.5em;
}

.av-prose li {
  margin-bottom: 0.45em;
}

.av-prose li::marker {
  color: var(--tone);
}

.av-prose strong {
  font-weight: 650;
  color: var(--slate-900);
}

.av-prose a {
  color: var(--tone);
  text-decoration: underline;
  text-decoration-color: var(--tone-line);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.2s;
}

.av-prose a:hover {
  text-decoration-color: var(--tone);
}

.av-prose blockquote {
  margin: 1.4em 0;
  padding: 16px 20px;
  border-left: 3px solid var(--tone-line);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--tone-soft);
  font-size: 15.5px;
  color: var(--slate-600);
}

.av-prose blockquote p:last-child {
  margin-bottom: 0;
}

.av-prose img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.6em auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--slate-200);
}

.av-prose figure {
  margin: 1.6em 0;
}

.av-prose figcaption {
  margin-top: 8px;
  font-size: 12.5px;
  text-align: center;
  color: var(--slate-400);
}

.av-prose table {
  width: 100%;
  margin: 1.5em 0;
  border-collapse: collapse;
  font-size: 14.5px;
}

.av-prose th,
.av-prose td {
  padding: 10px 12px;
  border: 1px solid var(--slate-200);
  text-align: left;
  vertical-align: top;
}

.av-prose th {
  background: var(--slate-50);
  font-weight: 600;
  color: var(--slate-800);
}

.av-prose code {
  padding: 2px 6px;
  border-radius: 5px;
  background: var(--slate-100);
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--slate-800);
}

.av-prose pre {
  margin: 1.4em 0;
  padding: 16px 18px;
  border-radius: var(--radius-lg);
  background: var(--slate-900);
  color: var(--slate-100);
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.7;
}

.av-prose pre code {
  padding: 0;
  background: transparent;
  color: inherit;
}

.av-prose hr {
  margin: 2em 0;
  border: 0;
  border-top: 1px solid var(--slate-200);
}

/* ---------- 21.6 侧栏 ---------- */
.av-aside {
  display: grid;
  gap: 18px;
  position: sticky;
  top: 88px;
}

.av-aside-card {
  padding: 22px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  background: var(--white);
}

.av-aside-card > h4 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 14px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--slate-400);
}

.av-aside-card > h4::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--tone);
}

.av-aside-nav {
  display: grid;
  gap: 2px;
}

.av-aside-nav a {
  display: block;
  padding: 9px 12px;
  border-radius: 7px;
  font-size: 14px;
  color: var(--slate-600);
  transition: background 0.2s, color 0.2s;
}

.av-aside-nav a:hover {
  background: var(--slate-50);
  color: var(--slate-900);
}

.av-aside-nav a.is-active {
  background: var(--tone-soft);
  font-weight: 600;
  color: var(--tone-deep);
}

.av-aside-list {
  display: grid;
  gap: 12px;
}

.av-aside-list a {
  display: grid;
  gap: 5px;
  font-size: 14px;
  line-height: 1.55;
  color: var(--slate-700);
  transition: color 0.2s;
}

.av-aside-list a:hover {
  color: var(--tone);
}

.av-aside-list span {
  font-size: 12px;
  color: var(--slate-400);
}

.av-aside-contact {
  display: grid;
  gap: 10px;
  font-size: 14px;
}

.av-aside-contact a,
.av-aside-contact span {
  display: flex;
  align-items: baseline;
  gap: 8px;
  color: var(--slate-700);
}

.av-aside-contact em {
  flex: none;
  font-style: normal;
  font-size: 12.5px;
  color: var(--slate-400);
}

.av-aside-card .av-btn {
  width: 100%;
  margin-top: 14px;
  justify-content: center;
}

/* ---------- 21.7 404 ---------- */
.av-404 {
  padding: 96px 0 110px;
  text-align: center;
}

.av-404-code {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(76px, 16vw, 148px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, var(--tone), var(--tone-deep));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.av-404 h1 {
  margin: 18px 0 12px;
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 650;
  color: var(--slate-900);
}

.av-404 p {
  max-width: 52ch;
  margin: 0 auto 30px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate-500);
}

.av-404-act {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

/* ---------- 21.8 页脚免责声明 ---------- */
.av-foot-note {
  margin-top: 36px;
  padding: 18px 20px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  background: var(--slate-50);
}

.av-foot-note p {
  margin: 0;
  font-size: 12px;
  line-height: 1.95;
  color: var(--slate-500);
}

/* ---------- 21.9 页脚站群三列 ---------- */
@media (min-width: 1024px) {
  .av-sites {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 1023px) {
  .av-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 32px;
    padding: 32px 0 56px;
  }

  .av-aside {
    position: static;
  }
}

@media (max-width: 767px) {
  .av-page-head {
    padding: 30px 0 26px;
  }

  .av-li {
    padding: 20px 18px 18px 20px;
  }

  .av-li h2 {
    font-size: 17px;
  }

  .av-prose {
    font-size: 16px;
    line-height: 1.9;
  }

  .av-prose h2 {
    font-size: 19px;
  }

  .av-prose h3 {
    font-size: 16.5px;
  }

  .av-pager-meta {
    margin-left: 0;
    width: 100%;
  }

  .av-404 {
    padding: 64px 0 76px;
  }
}

/* ---------- 21.10 空态 ---------- */
.av-empty {
  padding: 56px 24px 60px;
  border: 1px dashed var(--slate-300);
  border-radius: var(--radius-lg);
  background: var(--white);
  text-align: center;
}

.av-empty h2 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 650;
  color: var(--slate-800);
}

.av-empty p {
  max-width: 46ch;
  margin: 0 auto 24px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--slate-500);
}

/* 联系方式列在窄屏保持单列：长文本挤进两列会高低不齐 */
@media (max-width: 767px) {
  .av-foot-col--contact ul {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* 正文表格在窄屏允许横向滑动，避免多列挤成一团 */
@media (max-width: 767px) {
  .av-prose table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .av-prose th,
  .av-prose td {
    min-width: 108px;
  }
}