:root {
  --primary: #1a56db;
  --primary-dark: #1e40af;
  --primary-light: #dbeafe;
  --accent: #06b6d4;
  --green: #10b981;
  --amber: #f59e0b;
  --red: #ef4444;
  --bg: #f8fafc;
  --surface: #ffffff;
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --shadow-sm: 0 1px 3px rgba(15,23,42,.06);
  --shadow: 0 4px 24px rgba(15,23,42,.08);
  --shadow-lg: 0 12px 48px rgba(15,23,42,.12);
  --radius: 16px;
  --radius-sm: 10px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
.nav { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,.85); backdrop-filter: blur(16px) saturate(180%); border-bottom: 1px solid var(--border); }
.nav-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 64px; display: flex; align-items: center; justify-content: space-between; }
.nav-brand { display: flex; align-items: center; gap: 10px; font-size: 22px; font-weight: 800; color: var(--primary); }
.nav-brand .logo-icon { width: 36px; height: 36px; background: linear-gradient(135deg, var(--primary), var(--accent)); border-radius: 10px; display: grid; place-items: center; color: #fff; font-size: 20px; }
.nav-links { display: flex; gap: 28px; font-size: 15px; font-weight: 600; color: var(--text-secondary); }
.nav-links a { transition: color .2s; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.nav-cta .btn { padding: 8px 20px; font-size: 14px; }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text); }
@media (max-width: 768px) {
  .nav-links { display: none; }
  .mobile-menu-btn { display: block; }
  .nav-links.open { display: flex; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0; background: #fff; border-bottom: 1px solid var(--border); padding: 16px 24px; gap: 12px; box-shadow: var(--shadow); }
}
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; border-radius: 10px; font-weight: 700; font-size: 15px; cursor: pointer; transition: all .2s; border: 1px solid transparent; line-height: 1; text-align: center; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 16px rgba(26,86,219,.25); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); box-shadow: 0 6px 24px rgba(26,86,219,.35); }
.btn-outline { background: #fff; border-color: var(--border); color: var(--text); }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-lg { padding: 16px 36px; font-size: 17px; border-radius: 12px; }
.btn-white { background: #fff; color: var(--primary); font-weight: 700; }
.btn-white:hover { background: var(--primary-light); }
.section { padding: 80px 0; }
.section-alt { background: var(--surface); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section-head { text-align: center; max-width: 700px; margin: 0 auto 56px; }
.section-tag { display: inline-block; padding: 4px 14px; background: var(--primary-light); color: var(--primary); border-radius: 99px; font-size: 13px; font-weight: 700; letter-spacing: .5px; margin-bottom: 16px; }
.section-title { font-size: clamp(28px,4vw,38px); font-weight: 800; margin-bottom: 16px; letter-spacing: -.5px; }
.section-desc { color: var(--text-secondary); font-size: 17px; line-height: 1.7; }
.hero { padding: 100px 0 80px; background: radial-gradient(ellipse 80% 60% at 50% -10%, rgba(26,86,219,.08) 0%, transparent 60%); position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: -200px; right: -200px; width: 600px; height: 600px; border-radius: 50%; background: radial-gradient(circle, rgba(6,182,212,.06) 0%, transparent 70%); pointer-events: none; }
.hero-content { max-width: 900px; margin: 0 auto; text-align: center; position: relative; z-index: 1; }
.hero-badge { display: inline-flex; align-items: center; gap: 8px; padding: 6px 18px; background: var(--primary-light); color: var(--primary); border-radius: 99px; font-size: 14px; font-weight: 700; margin-bottom: 28px; }
.hero-badge .dot { width: 8px; height: 8px; background: var(--green); border-radius: 50%; animation: pulse-dot 2s infinite; }
@keyframes pulse-dot { 0%,100%{opacity:1} 50%{opacity:.4} }
.hero h1 { font-size: clamp(36px,5.5vw,60px); font-weight: 900; line-height: 1.15; letter-spacing: -1.5px; margin-bottom: 24px; }
.hero h1 .gradient { background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p { font-size: 19px; color: var(--text-secondary); max-width: 640px; margin: 0 auto 36px; line-height: 1.7; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-stats { display: flex; justify-content: center; gap: 48px; margin-top: 56px; padding-top: 40px; border-top: 1px solid var(--border); }
.hero-stat { text-align: center; }
.hero-stat-num { font-size: 32px; font-weight: 900; color: var(--primary); }
.hero-stat-label { font-size: 14px; color: var(--text-muted); margin-top: 4px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 36px; transition: all .25s; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #bfdbfe; }
.card-icon { width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center; font-size: 28px; margin-bottom: 20px; }
.card-icon.blue { background: #eff6ff; color: var(--primary); }
.card-icon.cyan { background: #ecfeff; color: var(--accent); }
.card-icon.green { background: #ecfdf5; color: var(--green); }
.card-icon.amber { background: #fffbeb; color: var(--amber); }
.card h3 { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
.card p { color: var(--text-secondary); font-size: 15px; }
.ai-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.ai-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; transition: all .2s; }
.ai-card:hover { border-color: #bfdbfe; box-shadow: var(--shadow-sm); }
.ai-card .ai-icon { font-size: 32px; margin-bottom: 12px; }
.ai-card h4 { font-size: 17px; font-weight: 700; margin-bottom: 6px; }
.ai-card .tag { display: inline-block; padding: 2px 10px; background: #f0fdf4; color: #15803d; border-radius: 6px; font-size: 12px; font-weight: 600; margin-top: 8px; }
.ai-card .tag.new { background: #eff6ff; color: var(--primary); }
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border-radius: var(--radius); border: 1px solid var(--border); }
.comp-table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 700px; }
.comp-table th, .comp-table td { padding: 14px 18px; text-align: center; border-bottom: 1px solid var(--border); }
.comp-table thead th { background: #f8fafc; font-weight: 700; font-size: 13px; color: var(--text-secondary); position: sticky; top: 0; }
.comp-table thead th:first-child { text-align: left; border-radius: var(--radius) 0 0 0; }
.comp-table thead th:last-child { border-radius: 0 var(--radius) 0 0; }
.comp-table tbody td:first-child { text-align: left; font-weight: 600; }
.comp-table .check { color: var(--green); font-weight: 700; }
.comp-table .cross { color: var(--text-muted); }
.comp-table .star { color: var(--amber); font-weight: 700; }
.security-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.pricing-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; align-items: start; }
.price-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 36px; text-align: center; transition: all .2s; }
.price-card.featured { border-color: var(--primary); box-shadow: 0 0 0 1px var(--primary), var(--shadow-lg); position: relative; }
.price-card.featured::before { content: '推荐'; position: absolute; top: -12px; left: 50%; transform: translateX(-50%); background: var(--primary); color: #fff; padding: 4px 16px; border-radius: 99px; font-size: 13px; font-weight: 700; }
.price-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.price-name { font-size: 18px; font-weight: 700; margin-bottom: 16px; }
.price-value { font-size: 40px; font-weight: 900; color: var(--primary); margin-bottom: 8px; }
.price-value span { font-size: 16px; font-weight: 500; color: var(--text-muted); }
.price-desc { color: var(--text-secondary); font-size: 14px; margin-bottom: 24px; }
.price-features { list-style: none; text-align: left; margin-bottom: 28px; }
.price-features li { padding: 8px 0; font-size: 14px; color: var(--text-secondary); border-bottom: 1px solid var(--border-light); }
.price-features li:last-child { border: none; }
.price-features li::before { content: '\2713'; color: var(--green); font-weight: 700; margin-right: 8px; }
.cta { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%); border-radius: var(--radius); padding: 56px 48px; text-align: center; color: #fff; }
.cta h2 { font-size: 32px; font-weight: 800; margin-bottom: 16px; }
.cta p { font-size: 17px; opacity: .9; margin-bottom: 32px; }
.cta small { display: block; margin-top: 16px; opacity: .7; font-size: 13px; }
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
@media (max-width: 768px) { .about-grid { grid-template-columns: 1fr; } }
.footer { background: #0f172a; color: #94a3b8; padding: 48px 0 32px; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
@media (max-width: 768px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer h4 { color: #fff; font-size: 15px; font-weight: 700; margin-bottom: 16px; }
.footer a { color: #64748b; display: block; padding: 4px 0; transition: color .2s; }
.footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid #1e293b; padding-top: 24px; text-align: center; font-size: 13px; }
.tabs { display: flex; justify-content: center; gap: 8px; margin-bottom: 40px; flex-wrap: wrap; }
.tab-btn { padding: 10px 24px; border-radius: 10px; font-weight: 600; font-size: 14px; cursor: pointer; background: var(--surface); border: 1px solid var(--border); transition: all .2s; }
.tab-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.download-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
@media (max-width: 768px) { .download-grid { grid-template-columns: 1fr; } }
.fade-in { opacity: 0; transform: translateY(20px); transition: all .6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
@media (max-width: 768px) { .steps { grid-template-columns: 1fr 1fr; } }
.step { text-align: center; }
.step-num { width: 48px; height: 48px; background: var(--primary); color: #fff; border-radius: 50%; display: grid; place-items: center; font-size: 20px; font-weight: 800; margin: 0 auto 16px; }
.step h4 { font-weight: 700; margin-bottom: 8px; }
.step p { color: var(--text-secondary); font-size: 14px; }
.faq-item { border-bottom: 1px solid var(--border); padding: 20px 0; }
.faq-item summary { cursor: pointer; font-weight: 700; font-size: 17px; list-style: none; display: flex; justify-content: space-between; align-items: center; }
.faq-item summary::after { content: '+'; font-size: 22px; color: var(--text-muted); transition: transform .2s; }
.faq-item[open] summary::after { content: '\2212'; color: var(--primary); }
.faq-item p { color: var(--text-secondary); margin-top: 12px; padding-right: 24px; }