:root{
  --bg:#f6f6f9;
  --surface:#fff;
  --text-primary:#1a1a2e;
  --text-secondary:#696976;
  --text-tertiary:#9696a3;
  --border:#e8e8ee;
  --border-light:#f2f2f6;
  --accent:#4361ee;
  --accent-2:#7c3aed;
  --accent-light:#eef1fd;
  --radius:14px;
  --radius-xs:7px;
  --shadow-hover:0 4px 16px rgba(0,0,0,.06),0 2px 4px rgba(0,0,0,.03);
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",Arial,sans-serif;background:var(--bg);color:var(--text-primary);line-height:1.65;min-height:100vh}
a{text-decoration:none;color:inherit}
.topbar{position:sticky;top:0;z-index:20;height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 32px;background:rgba(255,255,255,.86);backdrop-filter:blur(20px);border-bottom:1px solid var(--border-light)}
.topbar-brand{display:flex;align-items:center;gap:10px;color:var(--text-primary);font-weight:700}
.logo-mark{width:32px;height:32px;border-radius:8px}
.topbar-nav{display:flex;gap:4px;position:absolute;left:50%;transform:translateX(-50%)}
.topbar-nav a{padding:8px 14px;border-radius:8px;color:var(--text-secondary);font-size:15px}
.topbar-nav a:hover,.topbar-nav a.active{color:var(--accent);background:var(--accent-light)}
.topbar-actions{display:flex;gap:8px}
.btn-login,.btn-register{padding:9px 20px;border-radius:var(--radius-xs);font-size:15px}
.btn-login{color:var(--text-primary);background:var(--surface);border:1px solid var(--border)}
.btn-register{color:#fff;background:var(--accent);font-weight:600}
.landing-main{max-width:1200px;margin:0 auto;padding:32px}
.hero-card{background:linear-gradient(135deg,var(--accent) 0%,var(--accent-2) 100%);border-radius:var(--radius);padding:72px 48px;text-align:center;margin-bottom:32px;position:relative;overflow:hidden}
.hero-card:before{content:"";position:absolute;top:-50%;right:-20%;width:500px;height:500px;background:radial-gradient(circle,rgba(255,255,255,.08) 0%,transparent 70%);border-radius:50%}
.hero-card>*{position:relative;z-index:1}
.hero-card h1{font-size:36px;line-height:1.25;color:#fff;margin-bottom:16px}
.hero-card p{font-size:15px;color:rgba(255,255,255,.86);max-width:660px;margin:0 auto 32px}
.hero-actions{display:flex;justify-content:center;gap:12px}
.hero-btn{display:inline-flex;align-items:center;justify-content:center;padding:12px 30px;border-radius:var(--radius-xs);font-size:16px;font-weight:600}
.hero-btn-primary{background:#fff;color:var(--accent)}
.hero-btn-secondary{background:rgba(255,255,255,.15);color:#fff;border:1px solid rgba(255,255,255,.25)}
.trial-bar{margin:-8px 0 32px;padding:16px 20px;border-radius:var(--radius);background:var(--accent-light);text-align:center;font-weight:600}
.trial-bar a{color:var(--accent)}
.section-block{margin-bottom:32px}
.section-title{font-size:22px;line-height:1.3;margin-bottom:8px}
.section-subtitle{font-size:15px;color:var(--text-tertiary);margin-bottom:24px}
.features-grid,.article-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.article-grid{grid-template-columns:repeat(3,1fr)}
.feature-card,.plan-card,.stat-card,.content-panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:28px 24px}
.feature-card:hover,.plan-card:hover,.article-card:hover{border-color:var(--accent);box-shadow:var(--shadow-hover)}
.feature-icon-box{width:44px;height:44px;border-radius:var(--radius-xs);display:flex;align-items:center;justify-content:center;margin-bottom:18px;color:var(--accent)}
.feature-icon-box .ico{display:block}
.tone-blue{background:#eef1fd}
.tone-green{background:#eefbf3}
.tone-purple{background:#f3e8ff}
.tone-orange{background:#fff7e8}
.feature-card h2,.plan-card h2,.content-panel h2,.content-panel h1{font-size:17px;margin-bottom:8px}
.content-panel h1{font-size:28px;line-height:1.3;margin-bottom:16px}
.feature-card p,.content-panel p,.content-panel li{font-size:15px;color:var(--text-secondary)}
.content-panel p{margin-bottom:12px}
.content-panel h2{margin-top:22px}
.content-panel ul{margin:8px 0 16px 1.2em}
.plans-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.plan-card{position:relative;display:flex;flex-direction:column}
.plan-card.featured{border:2px solid var(--accent)}
.plan-badge-top{position:absolute;top:-1px;left:50%;transform:translateX(-50%);background:var(--accent);color:#fff;font-size:13px;font-weight:600;padding:3px 16px;border-radius:0 0 8px 8px}
.plan-price-val{font-size:32px;font-weight:700;color:var(--accent)}
.plan-price-unit{font-size:16px;color:var(--text-tertiary)}
.plan-features{list-style:none;margin:18px 0 24px}
.plan-features li{padding:7px 0;color:var(--text-secondary);font-size:15px}
.plan-btn{display:block;text-align:center;margin-top:auto;padding:12px;border-radius:var(--radius-xs);font-weight:600}
.plan-btn-primary{background:var(--accent);color:#fff}
.plan-btn-outline{border:1px solid var(--border);color:var(--accent);background:#fff}
.stats-row{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:32px}
.stat-card{text-align:center}
.stat-val{font-size:28px;font-weight:700;color:var(--accent)}
.stat-label{font-size:15px;color:var(--text-tertiary)}
.faq-item{border-bottom:1px solid var(--border-light);padding:20px 0}
.faq-item:last-child{border-bottom:none}
.faq-item h2{font-size:17px;margin-bottom:6px}
.update-list{display:flex;flex-direction:column;gap:12px}
.update-list a{display:block}
.update-date{display:block;color:var(--text-tertiary);font-size:13px;margin-bottom:4px}
.landing-footer{border-top:1px solid var(--border);padding:32px;text-align:center;max-width:1200px;margin:0 auto}
.footer-links{display:flex;gap:18px;justify-content:center;flex-wrap:wrap;margin-bottom:12px}
.footer-links a{color:var(--text-secondary);font-size:14px}
.footer-copy{font-size:14px;color:var(--text-tertiary)}
@media(max-width:900px){
  .topbar{height:auto;flex-wrap:wrap;padding:12px 16px;gap:8px}
  .topbar-nav{position:static;transform:none;flex-wrap:wrap}
  .features-grid,.article-grid,.plans-grid,.stats-row{grid-template-columns:1fr}
  .hero-card{padding:44px 22px}
  .hero-card h1{font-size:26px}
  .hero-actions{flex-direction:column}
}