/* ============================================
   易云拓 · 易云GEO — 设计系统 v2
   纯静态站 | PC + 移动端自适应 | AI科技风
   ============================================ */

:root {
  --bg-deep: #050b14;
  --bg-elevated: #0a1220;
  --bg-card: #0d1829;
  --bg-card-hover: #122038;
  --bg-section-alt: rgba(0, 102, 255, 0.03);

  --primary: #0066ff;
  --primary-light: #4d94ff;
  --accent: #00d4ff;
  --accent-purple: #8b6cff;
  --accent-green: #00e5a0;

  --text: #eef2f8;
  --text-secondary: #b4c4d9;
  --text-muted: #7a8fa8;

  --border: rgba(77, 148, 255, 0.18);
  --border-strong: rgba(0, 212, 255, 0.35);

  --gradient-brand: linear-gradient(135deg, #0066ff 0%, #00d4ff 55%, #8b6cff 100%);
  --gradient-soft: linear-gradient(180deg, rgba(0, 102, 255, 0.12) 0%, transparent 100%);
  --shadow-glow: 0 8px 40px rgba(0, 102, 255, 0.18);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.35);

  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 20px;

  --max-w: 1200px;
  --header-h: 68px;
  --mobile-bar-h: 56px;

  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 48px;
  --space-xl: 80px;

  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg-deep);
  color: var(--text);
  line-height: 1.75;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

body.nav-open { overflow: hidden; }

/* 全局科技网格背景 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 102, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 102, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 20%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

main, .site-header, .site-footer, .mobile-bar { position: relative; z-index: 1; }

a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-light); }

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

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--space-sm);
}

@media (min-width: 768px) {
  .container { padding: 0 var(--space-md); }
}

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9375rem;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  min-height: 48px;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-brand);
  color: #fff;
  box-shadow: 0 4px 20px rgba(0, 102, 255, 0.35);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
  color: #fff;
}

.btn-outline {
  background: rgba(255, 255, 255, 0.03);
  color: var(--text);
  border: 1px solid var(--border);
  backdrop-filter: blur(8px);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--accent);
  background: rgba(0, 102, 255, 0.08);
}

.btn-sm { padding: 10px 18px; font-size: 0.875rem; min-height: 40px; }

.hero-btns { display: flex; flex-wrap: wrap; gap: 12px; }

/* ========== 头部导航 ========== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(5, 11, 20, 0.85);
  backdrop-filter: blur(16px) saturate(1.2);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.site-header.scrolled {
  border-bottom-color: var(--border);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.4);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 12px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text);
  flex-shrink: 0;
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.5px;
  box-shadow: 0 2px 12px rgba(0, 102, 255, 0.4);
}

.logo-text span.logo-brand {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.logo-sep {
  color: var(--text-muted);
  margin: 0 3px;
  font-weight: 400;
  -webkit-text-fill-color: var(--text-muted);
}
.logo-product {
  color: var(--text);
  font-weight: 600;
  -webkit-text-fill-color: var(--text);
  background: none;
}

.logo-sub {
  display: block;
  font-size: 0.65rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.08em;
  margin-top: 1px;
}

.logo:hover { color: var(--text); }

.main-nav {
  display: none;
  align-items: center;
  gap: 2px;
}

.main-nav a {
  color: var(--text-muted);
  font-size: 0.875rem;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--text);
  background: rgba(0, 102, 255, 0.12);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header-phone {
  display: none;
  color: var(--text-secondary);
  font-size: 0.8125rem;
  font-weight: 600;
}

.header-phone:hover { color: var(--accent); }

.header-cta {
  background: var(--gradient-brand);
  color: #fff !important;
  padding: 10px 18px !important;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.875rem;
  min-height: 40px;
}

.header-cta:hover { opacity: 0.92; color: #fff !important; transform: translateY(-1px); }

.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 1.25rem;
  cursor: pointer;
}

.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  top: var(--header-h);
  background: rgba(0, 0, 0, 0.6);
  z-index: 998;
  opacity: 0;
  transition: opacity var(--transition);
}

.nav-overlay.open {
  display: block;
  opacity: 1;
}

@media (min-width: 1024px) {
  .main-nav { display: flex; }
  .menu-toggle { display: none; }
  .header-phone { display: block; }
}

@media (max-width: 1023px) {
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-sm);
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    transform: translateY(-110%);
    opacity: 0;
    transition: transform var(--transition), opacity var(--transition);
    z-index: 999;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }

  .main-nav.open {
    display: flex;
    transform: translateY(0);
    opacity: 1;
  }

  .main-nav a {
    padding: 14px 16px;
    font-size: 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
  }

  .main-nav a.active {
    border-color: var(--border);
    background: rgba(0, 102, 255, 0.1);
  }

  .header-cta { display: none; }
}

/* ========== Hero 首页 ========== */
.hero {
  padding: calc(var(--header-h) + 48px) 0 var(--space-xl);
  position: relative;
  overflow: hidden;
  min-height: 85vh;
  display: flex;
  align-items: center;
}

.hero .container { width: 100%; }

@media (max-width: 959px) {
  .hero { min-height: auto; padding-bottom: var(--space-lg); }
}

.hero::after {
  content: "";
  position: absolute;
  width: 600px; height: 600px;
  top: -200px; right: -150px;
  background: radial-gradient(circle, rgba(0, 102, 255, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px 6px 8px;
  background: rgba(0, 102, 255, 0.1);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.8125rem;
  color: var(--accent);
  margin-bottom: var(--space-md);
}

.hero-badge-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: center;
}

@media (min-width: 960px) {
  .hero { padding: calc(var(--header-h) + 60px) 0 var(--space-xl); }
  .hero-grid { grid-template-columns: 1.05fr 0.95fr; gap: 56px; }
}

.hero h1 {
  font-size: clamp(2rem, 5.5vw, 3.25rem);
  line-height: 1.2;
  margin-bottom: var(--space-md);
  letter-spacing: -0.03em;
  font-weight: 800;
}

.hero h1 em {
  font-style: normal;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  color: var(--text-secondary);
  font-size: clamp(0.9375rem, 2vw, 1.0625rem);
  margin-bottom: var(--space-md);
  max-width: 540px;
}

.hero-desc strong { color: var(--text); }

.hero-trust {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.trust-item svg { flex-shrink: 0; color: var(--accent); }

.hero-visual {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  position: relative;
  box-shadow: var(--shadow-card);
}

.hero-visual::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: var(--gradient-brand);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0.35;
  pointer-events: none;
}

.ai-flow { display: flex; flex-direction: column; gap: 12px; }

.ai-step {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px;
  background: rgba(0, 102, 255, 0.05);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary);
  transition: background var(--transition);
}

.ai-step:hover { background: rgba(0, 102, 255, 0.1); }

.ai-step .num {
  width: 32px; height: 32px;
  border-radius: 50%;
  background: var(--gradient-brand);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.8125rem;
  flex-shrink: 0;
}

.ai-step strong { display: block; font-size: 0.9375rem; margin-bottom: 4px; }
.ai-step small { color: var(--text-muted); font-size: 0.8125rem; line-height: 1.5; }

/* ========== 区块通用 ========== */
section { padding: var(--space-lg) 0; }

@media (min-width: 768px) {
  section { padding: var(--space-xl) 0; }
}

.section-alt { background: var(--bg-section-alt); }

.section-title {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.section-title .label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title h2 {
  font-size: clamp(1.625rem, 3.5vw, 2.25rem);
  margin-bottom: 12px;
  letter-spacing: -0.02em;
  font-weight: 700;
}

.section-title p {
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto;
  font-size: 0.9375rem;
}

.section-head-left {
  text-align: left;
  margin-bottom: var(--space-lg);
}

.section-head-left h2 { font-size: clamp(1.4rem, 3vw, 1.85rem); margin-bottom: 8px; }
.section-head-left p { color: var(--text-muted); max-width: 560px; }

/* ========== 卡片 ========== */
.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

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

@media (min-width: 960px) {
  .card-grid { grid-template-columns: repeat(4, 1fr); gap: var(--space-md); }
}

.card-grid-3 {
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .card-grid-3 { grid-template-columns: repeat(3, 1fr); }
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-md);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
  height: 100%;
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-glow);
}

.card-icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: rgba(0, 102, 255, 0.12);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.375rem;
  margin-bottom: 16px;
}

.card h3 { font-size: 1.0625rem; margin-bottom: 10px; }
.card p { color: var(--text-muted); font-size: 0.875rem; flex: 1; }
.card .link {
  margin-top: 16px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent);
}

/* ========== 数据统计 ========== */
.stats-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
}

@media (min-width: 768px) {
  .stats-row { grid-template-columns: repeat(4, 1fr); gap: var(--space-md); }
}

.stat-item {
  text-align: center;
  padding: var(--space-md) var(--space-sm);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}

.stat-item:hover { border-color: var(--border-strong); }

.stat-item .num {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 800;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.stat-item .label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 6px;
}

/* ========== 平台标签 ========== */
.platform-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: var(--space-md);
}

.platform-badge {
  padding: 8px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

/* ========== 流程步骤 ========== */
.process-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
  counter-reset: step;
}

@media (min-width: 768px) {
  .process-row { grid-template-columns: repeat(4, 1fr); }
}

.process-item {
  position: relative;
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
}

.process-item::before {
  counter-increment: step;
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  margin: 0 auto 12px;
  border-radius: 50%;
  background: var(--gradient-brand);
  font-weight: 700;
  font-size: 0.875rem;
}

.process-item h4 { font-size: 0.9375rem; margin-bottom: 6px; }
.process-item p { font-size: 0.8125rem; color: var(--text-muted); }

/* ========== 区域网格 ========== */
.district-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

@media (min-width: 640px) {
  .district-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 960px) {
  .district-grid { grid-template-columns: repeat(4, 1fr); gap: 16px; }
}

.district-link {
  display: block;
  padding: 18px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  color: var(--text);
  transition: all var(--transition);
}

.district-link:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  color: var(--accent);
  box-shadow: var(--shadow-glow);
}

.district-link strong { display: block; font-size: 1rem; margin-bottom: 4px; }
.district-link span { font-size: 0.75rem; color: var(--text-muted); line-height: 1.4; display: block; }

/* ========== 内页 Hero ========== */
.page-hero {
  padding: calc(var(--header-h) + 32px) 0 36px;
  background: var(--gradient-soft);
  border-bottom: 1px solid var(--border);
  position: relative;
}

@media (min-width: 768px) {
  .page-hero { padding: calc(var(--header-h) + 48px) 0 48px; }
}

.page-hero h1 {
  font-size: clamp(1.5rem, 4vw, 2.125rem);
  margin-bottom: 14px;
  letter-spacing: -0.02em;
  max-width: 800px;
}

.page-hero .lead {
  color: var(--text-secondary);
  font-size: clamp(0.9375rem, 2vw, 1.0625rem);
  max-width: 720px;
}

.breadcrumb {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent); }

.breadcrumb-nav { margin-bottom: 18px; }
.breadcrumb-list {
  display: flex; flex-wrap: wrap; align-items: center; gap: 6px;
  list-style: none; font-size: 0.8125rem; color: var(--text-muted);
}
.breadcrumb-list li:not(:last-child)::after {
  content: "›"; margin-left: 6px; opacity: 0.5;
}
.breadcrumb-list a { color: var(--text-muted); }
.breadcrumb-list [aria-current="page"] { color: var(--text-secondary); }

.section-desc {
  color: var(--text-muted); font-size: 0.9375rem;
  margin-bottom: 20px; max-width: 720px;
}

.content-layout {
  display: grid; grid-template-columns: 1fr; gap: var(--space-md);
}
@media (min-width: 960px) {
  .content-layout { grid-template-columns: 1fr 300px; gap: 40px; }
}
.content-main .prose { max-width: 100%; }

.sidebar-box {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px; margin-bottom: 16px;
}
.sidebar-box h3 {
  font-size: 0.9375rem; margin-bottom: 14px; padding-bottom: 10px;
  border-bottom: 1px solid var(--border); color: var(--accent);
}
.related-links { list-style: none; }
.related-links li { margin-bottom: 8px; }
.related-links a { font-size: 0.875rem; color: var(--text-secondary); }
.related-links a:hover { color: var(--accent); }
.mini-faq { margin-bottom: 12px; }
.mini-faq h4 { font-size: 0.875rem; margin-bottom: 4px; }
.mini-faq p { font-size: 0.8125rem; color: var(--text-muted); }
.hub-intro { margin-bottom: 32px; padding-bottom: 24px; border-bottom: 1px solid var(--border); }

.footer-sister {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
}
.footer-sister strong { color: var(--text-secondary); }

.sister-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 20px 0 32px;
}
@media (min-width: 640px) {
  .sister-grid { grid-template-columns: 1fr; max-width: 640px; }
}
.sister-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.sister-card h3 { font-size: 1rem; margin-bottom: 10px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.sister-card p { font-size: 0.875rem; color: var(--text-secondary); margin-bottom: 8px; }

@media (min-width: 960px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr 1fr; }
}

/* ========== 正文 ========== */
.content-section { padding: var(--space-lg) 0; }

.prose { max-width: 820px; }
.prose h2 { font-size: 1.375rem; margin: 36px 0 14px; color: var(--accent); }
.prose h3 { font-size: 1.0625rem; margin: 28px 0 10px; color: var(--text); }
.prose p { margin-bottom: 16px; color: var(--text-secondary); }
.prose ul, .prose ol { margin: 0 0 16px 22px; color: var(--text-secondary); }
.prose li { margin-bottom: 8px; }
.prose strong { color: var(--text); }

.content-wide { max-width: 100%; }

/* ========== 表格（移动端横向滚动） ========== */
.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: var(--space-md) 0;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.data-table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  background: var(--bg-card);
}

.data-table th, .data-table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

.data-table th {
  background: rgba(0, 102, 255, 0.1);
  color: var(--text);
  font-weight: 600;
  font-size: 0.875rem;
  white-space: nowrap;
}

.data-table td { color: var(--text-secondary); font-size: 0.875rem; }
.data-table tr:last-child td { border-bottom: none; }

/* ========== FAQ ========== */
.faq-list { display: flex; flex-direction: column; gap: 10px; }

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition);
}

.faq-item.open { border-color: var(--border-strong); }

.faq-q {
  padding: 18px 20px;
  font-weight: 600;
  font-size: 0.9375rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  min-height: 56px;
}

.faq-q::after {
  content: "+";
  color: var(--accent);
  font-size: 1.25rem;
  flex-shrink: 0;
  width: 28px; height: 28px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(0, 102, 255, 0.1);
  border-radius: 6px;
}

.faq-item.open .faq-q::after { content: "−"; }

.faq-a {
  padding: 0 20px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.75;
}

.faq-item.open .faq-a { padding: 0 20px 18px; max-height: 600px; }

/* ========== 案例 ========== */
.case-card .tag {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  background: rgba(0, 212, 255, 0.12);
  color: var(--accent);
  margin-bottom: 12px;
}

.case-card .tag.b2b { background: rgba(139, 108, 255, 0.15); color: var(--accent-purple); }

/* ========== CTA ========== */
.cta-band {
  background: linear-gradient(135deg, rgba(0, 102, 255, 0.12), rgba(139, 108, 255, 0.08));
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: var(--space-lg) var(--space-md);
  text-align: center;
  margin: var(--space-lg) 0;
  position: relative;
  overflow: hidden;
}

.cta-band::before {
  content: "";
  position: absolute;
  width: 300px; height: 300px;
  top: -150px; right: -100px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.1), transparent);
  pointer-events: none;
}

.cta-band h2 { margin-bottom: 10px; font-size: clamp(1.25rem, 3vw, 1.625rem); }
.cta-band p { color: var(--text-muted); margin-bottom: var(--space-md); max-width: 520px; margin-left: auto; margin-right: auto; }

/* ========== 页脚 ========== */
.site-footer {
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  padding: var(--space-lg) 0 var(--space-md);
  margin-top: var(--space-md);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

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

@media (min-width: 960px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-top: 12px;
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 0.9375rem;
  margin-bottom: 14px;
  color: var(--text);
}

.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { color: var(--text-muted); font-size: 0.875rem; }
.footer-col a:hover { color: var(--accent); }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-align: center;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.footer-domain {
  color: var(--text-muted);
  font-size: 0.8125rem;
  margin-top: 8px;
}

.footer-domain a { color: var(--accent); }

/* ========== 移动端底部栏 ========== */
.mobile-bar {
  display: flex;
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 900;
  height: var(--mobile-bar-h);
  background: rgba(10, 18, 32, 0.95);
  backdrop-filter: blur(16px);
  border-top: 1px solid var(--border);
  padding-bottom: env(safe-area-inset-bottom, 0);
}

@media (min-width: 768px) {
  .mobile-bar { display: none; }
  body { padding-bottom: 0; }
}

@media (max-width: 767px) {
  body { padding-bottom: calc(var(--mobile-bar-h) + env(safe-area-inset-bottom, 0)); }
}

.mobile-bar a {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  color: var(--text-muted);
  font-size: 0.6875rem;
  padding: 8px 4px;
  transition: color var(--transition);
}

.mobile-bar a svg { width: 22px; height: 22px; }

.mobile-bar a.active,
.mobile-bar a:hover { color: var(--accent); }

.mobile-bar a.bar-cta {
  flex: 1.3;
  background: var(--gradient-brand);
  color: #fff;
  margin: 6px 8px;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-weight: 600;
}

.mobile-bar a.bar-cta:hover { color: #fff; }

/* ========== 返回顶部 ========== */
.back-top {
  position: fixed;
  right: 16px;
  bottom: calc(var(--mobile-bar-h) + 16px + env(safe-area-inset-bottom, 0));
  width: 44px; height: 44px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
  z-index: 800;
  font-size: 1.125rem;
}

@media (min-width: 768px) {
  .back-top { bottom: 24px; }
}

.back-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top:hover {
  border-color: var(--primary);
  background: rgba(0, 102, 255, 0.15);
}

/* ========== 双栏 / 联系 ========== */
.two-col {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

@media (min-width: 960px) {
  .two-col { grid-template-columns: 1fr 1fr; gap: 40px; }
}

.tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0; }

.tag-pill {
  padding: 6px 14px;
  border-radius: 100px;
  font-size: 0.8125rem;
  background: rgba(0, 102, 255, 0.1);
  color: var(--primary-light);
  border: 1px solid var(--border);
}

.article-list { display: flex; flex-direction: column; gap: 12px; }

.article-item {
  padding: 18px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}

.article-item:hover { border-color: var(--border-strong); }

.article-item .meta { font-size: 0.75rem; color: var(--text-muted); margin-bottom: 6px; }
.article-item h3 { font-size: 1rem; margin-bottom: 6px; }
.article-item h3 a { color: var(--text); }
.article-item h3 a:hover { color: var(--accent); }
.article-item p { font-size: 0.8125rem; color: var(--text-muted); }

.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .contact-grid { grid-template-columns: 1fr 1fr; }
}

.contact-card {
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  height: 100%;
}

.contact-card h3 { margin-bottom: 16px; font-size: 1.125rem; }

.contact-item {
  display: flex;
  gap: 12px;
  margin-bottom: 14px;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.contact-item strong { color: var(--text); min-width: 72px; flex-shrink: 0; }

/* ========== 工具类 ========== */
.text-center { text-align: center; }
.mt-lg { margin-top: var(--space-lg); }
.hidden-mobile { display: none; }

@media (min-width: 768px) {
  .hidden-mobile { display: block; }
  .hidden-desktop { display: none; }
}

/* ========== 知识库 / 法律页 ========== */
.article-meta {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--border);
}

.category-heading {
  margin: var(--space-lg) 0 var(--space-sm);
  font-size: 1rem;
  color: var(--accent);
  letter-spacing: 0.02em;
}

.category-heading:first-of-type { margin-top: 0; }

.legal-content h2 {
  margin-top: var(--space-lg);
  font-size: 1.125rem;
}

.legal-content p,
.legal-content li {
  color: var(--text-secondary);
  line-height: 1.75;
}

.footer-bottom a {
  color: var(--text-muted);
  text-decoration: none;
}

.footer-bottom a:hover { color: var(--accent); }

.contact-grid-3 {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .contact-grid-3 {
    grid-template-columns: 1fr 1fr;
  }

  .contact-grid-3 .contact-card:first-child {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .contact-grid-3 {
    grid-template-columns: 1.15fr 0.75fr 1fr;
    align-items: start;
  }

  .contact-grid-3 .contact-card:first-child {
    grid-column: auto;
  }
}

.contact-card-qr { text-align: center; }

.wechat-qr {
  display: block;
  margin: 8px auto 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  object-fit: contain;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.wechat-qr--md {
  width: min(148px, 42vw);
  max-width: 148px;
  height: auto;
  aspect-ratio: 1;
}

.wechat-qr--sm {
  width: min(128px, 36vw);
  max-width: 128px;
  height: auto;
  aspect-ratio: 1;
}

.trust-card-qr {
  flex: 0 0 auto;
}

.license-img {
  width: min(280px, 78vw);
  max-width: 280px;
  height: auto;
  margin: 0 auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: #fff;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.trust-card-license {
  flex: 0 0 auto;
}

@media (max-width: 479px) {
  .contact-item {
    flex-direction: column;
    gap: 4px;
    margin-bottom: 12px;
  }

  .contact-item strong {
    min-width: 0;
    font-size: 0.8125rem;
  }

  .contact-card {
    padding: 18px;
  }

  .footer-bottom span {
    line-height: 1.6;
  }

  .hero-btns .btn {
    width: 100%;
    white-space: normal;
    text-align: center;
  }

  .faq-q {
    font-size: 0.875rem;
    padding: 16px;
  }

  .faq-item.open .faq-a {
    max-height: 1200px;
  }
}

@media (max-width: 767px) {
  .stats-row {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .stat-item .num {
    font-size: 1.75rem;
  }

  .platform-row {
    justify-content: flex-start;
    gap: 8px;
  }

  .platform-badge {
    font-size: 0.75rem;
    padding: 6px 10px;
  }

  .trust-media {
    justify-content: center;
  }
}

@media (min-width: 768px) and (max-width: 899px) {
  .contact-grid-3 .contact-card-qr {
    max-width: 280px;
    justify-self: center;
  }
}

.trust-media {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-sm);
}

.trust-card {
  margin: 0;
  text-align: center;
}

.trust-card img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.trust-card figcaption {
  margin-top: 8px;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.contact-faq .mini-faq-box { max-width: 720px; }