/* 阿白易学工具官网共享样式 - 简洁现代风 */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#667eea;--primary-dark:#5a6fd6;--secondary:#764ba2;
  --text:#333;--text-muted:#666;--text-light:#999;
  --bg:#fff;--bg-soft:#f8f9fc;--bg-card:#fff;
  --border:#eaecef;--success:#52c41a;--warning:#faad14;
  --radius:12px;--shadow-sm:0 2px 8px rgba(0,0,0,.06);
  --shadow:0 8px 24px rgba(0,0,0,.08);--shadow-lg:0 20px 60px rgba(0,0,0,.12);
  --max-w:1100px;
}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;
  color:var(--text);background:var(--bg);line-height:1.7;font-size:16px;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--primary);text-decoration:none;transition:color .2s}
a:hover{color:var(--secondary)}
img{max-width:100%;height:auto;display:block}

/* ===== Header ===== */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(255,255,255,.92);backdrop-filter:blur(12px);
  border-bottom:1px solid var(--border);
}
.nav-bar{max-width:var(--max-w);margin:0 auto;padding:14px 24px;display:flex;align-items:center;justify-content:space-between}
.brand{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:700;color:var(--text)}
.brand:hover{color:var(--text)}
.brand .logo{width:32px;height:32px;object-fit:cover;border-radius:8px;display:block;background:transparent}
.nav-links{display:flex;align-items:center;gap:28px;list-style:none}
.nav-links a{color:var(--text);font-size:15px;font-weight:500}
.nav-links a:hover{color:var(--primary)}
.nav-cta{background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;padding:8px 20px;border-radius:8px;font-weight:600}
.nav-cta:hover{color:#fff;filter:brightness(1.05)}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;font-size:24px}

/* ===== Hero ===== */
.hero{
  background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);
  color:#fff;padding:80px 24px;text-align:center;position:relative;overflow:hidden;
}
.hero::before{content:"";position:absolute;inset:0;background:radial-gradient(circle at 30% 20%,rgba(255,255,255,.15),transparent 50%);pointer-events:none}
.hero-inner{max-width:var(--max-w);margin:0 auto;position:relative}
.hero h1{font-size:42px;margin-bottom:16px;font-weight:700;letter-spacing:1px}
.hero .tagline{font-size:20px;opacity:.95;margin-bottom:32px;font-weight:300}
.hero-cta{display:inline-flex;gap:14px;flex-wrap:wrap;justify-content:center}
.btn{display:inline-block;padding:14px 32px;border-radius:10px;font-weight:600;font-size:16px;transition:all .2s;cursor:pointer;border:none}
.btn-primary{background:#fff;color:var(--primary)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 20px rgba(0,0,0,.2);color:var(--primary)}
.btn-outline{background:rgba(255,255,255,.12);color:#fff;border:2px solid rgba(255,255,255,.6)}
.btn-outline:hover{background:rgba(255,255,255,.22);color:#fff}
.hero-meta{margin-top:24px;font-size:14px;opacity:.85}
.hero-meta strong{font-weight:600}

/* ===== Sections ===== */
.section{padding:64px 24px}
.section-inner{max-width:var(--max-w);margin:0 auto}
.section-title{text-align:center;font-size:32px;font-weight:700;margin-bottom:12px;color:var(--text)}
.section-subtitle{text-align:center;color:var(--text-muted);font-size:17px;margin-bottom:48px;max-width:680px;margin-left:auto;margin-right:auto}
.section-soft{background:var(--bg-soft)}

/* Feature grid */
.feature-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px;margin-top:32px}
.feature-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:28px;transition:all .2s;box-shadow:var(--shadow-sm)}
.feature-card:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:var(--primary)}
.feature-icon{width:48px;height:48px;background:linear-gradient(135deg,var(--primary),var(--secondary));border-radius:10px;display:flex;align-items:center;justify-content:center;color:#fff;font-size:22px;margin-bottom:16px}
.feature-card h3{font-size:18px;margin-bottom:8px;color:var(--text)}
.feature-card p{color:var(--text-muted);font-size:14px;line-height:1.7}

/* Pricing / Membership */
.plans{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:24px;margin-top:32px}
.plan-card{background:#fff;border:1px solid var(--border);border-radius:var(--radius);padding:32px 24px;text-align:center;position:relative;transition:all .2s}
.plan-card:hover{box-shadow:var(--shadow)}
.plan-card.featured{border:2px solid var(--primary);box-shadow:var(--shadow)}
.plan-card.featured::before{content:"推荐";position:absolute;top:-12px;left:50%;transform:translateX(-50%);background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;padding:4px 16px;border-radius:20px;font-size:12px;font-weight:600}
.plan-name{font-size:20px;font-weight:600;margin-bottom:8px;color:var(--text)}
.plan-price{font-size:36px;font-weight:700;color:var(--primary);margin:12px 0}
.plan-price small{font-size:14px;color:var(--text-light);font-weight:400}
.plan-desc{color:var(--text-muted);font-size:14px;margin-bottom:20px}
.plan-features{list-style:none;text-align:left;margin-bottom:24px}
.plan-features li{padding:6px 0 6px 24px;position:relative;color:var(--text-muted);font-size:14px}
.plan-features li::before{content:"✓";position:absolute;left:0;color:var(--success);font-weight:700}
.plan-features li.disabled{color:var(--text-light);text-decoration:none;opacity:.6}
.plan-features li.disabled::before{content:"✗";color:var(--text-light)}

/* Download cards */
.download-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;margin-top:32px}
.dl-card{background:#fff;border:1px solid var(--border);border-radius:var(--radius);padding:24px;display:flex;align-items:center;gap:20px;transition:all .2s}
.dl-card:hover{border-color:var(--primary);box-shadow:var(--shadow-sm);transform:translateY(-2px)}
.dl-icon{width:56px;height:56px;background:linear-gradient(135deg,#f0f4ff,#e6e9ff);border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:28px}
.dl-info{flex:1}
.dl-name{font-weight:600;font-size:17px;color:var(--text)}
.dl-size{color:var(--text-light);font-size:13px;margin-top:2px}
.dl-btn{background:var(--primary);color:#fff;padding:10px 22px;border-radius:8px;font-weight:600;font-size:14px;white-space:nowrap}
.dl-btn:hover{background:var(--primary-dark);color:#fff}

/* FAQ */
.faq-list{max-width:760px;margin:32px auto 0}
.faq-item{background:#fff;border:1px solid var(--border);border-radius:10px;margin-bottom:12px;overflow:hidden}
.faq-q{padding:18px 24px;cursor:pointer;font-weight:600;color:var(--text);display:flex;justify-content:space-between;align-items:center;font-size:15px}
.faq-q .icon{color:var(--primary);transition:transform .2s}
.faq-item.open .icon{transform:rotate(45deg)}
.faq-a{padding:0 24px;max-height:0;overflow:hidden;color:var(--text-muted);font-size:14px;transition:all .3s}
.faq-item.open .faq-a{padding:0 24px 18px;max-height:300px}

/* CTA band */
.cta-band{background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;padding:48px 24px;text-align:center;border-radius:var(--radius);margin:48px auto;max-width:var(--max-w)}
.cta-band h2{font-size:26px;margin-bottom:8px}
.cta-band p{opacity:.9;margin-bottom:24px}

/* Footer */
.site-footer{background:#1a1a2e;color:rgba(255,255,255,.7);padding:48px 24px 24px;margin-top:64px}
.footer-grid{max-width:var(--max-w);margin:0 auto;display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:32px;margin-bottom:32px}
.footer-brand .brand{color:#fff;margin-bottom:12px}
.footer-brand p{font-size:14px;line-height:1.7;opacity:.8}
.footer-col h4{color:#fff;font-size:15px;margin-bottom:12px;font-weight:600}
.footer-col ul{list-style:none}
.footer-col li{margin-bottom:8px;font-size:14px}
.footer-col a{color:rgba(255,255,255,.7)}
.footer-col a:hover{color:#fff}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:20px;text-align:center;font-size:13px;opacity:.6;max-width:var(--max-w);margin:0 auto}
.footer-icp{padding-top:12px;text-align:center;font-size:12px;opacity:.6;max-width:var(--max-w);margin:0 auto;line-height:1.9}
.footer-icp a{color:rgba(255,255,255,.7);text-decoration:none}
.footer-icp a:hover{color:#fff;text-decoration:underline}
.footer-icp .icp-badge{vertical-align:middle;margin-right:4px;opacity:.85}
@media(max-width:768px){.footer-icp{font-size:11px;line-height:1.8}}

/* Page header (sub pages) */
.page-header{background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:#fff;padding:64px 24px;text-align:center}
.page-header h1{font-size:36px;font-weight:700;margin-bottom:8px}
.page-header p{opacity:.9;font-size:17px;max-width:680px;margin:0 auto}

/* Content blocks */
.content-block{max-width:760px;margin:0 auto;padding:48px 24px}
.content-block h2{font-size:24px;margin:32px 0 16px;color:var(--text)}
.content-block h3{font-size:19px;margin:24px 0 12px;color:var(--text)}
.content-block p{color:var(--text-muted);margin-bottom:14px}
.content-block ul{margin:0 0 16px 24px;color:var(--text-muted)}
.content-block li{margin-bottom:6px}

/* Responsive */
@media(max-width:768px){
  .nav-links{display:none;position:absolute;top:60px;left:0;right:0;background:#fff;border-bottom:1px solid var(--border);padding:16px;flex-direction:column;gap:12px;align-items:flex-start}
  .nav-links.open{display:flex}
  .nav-toggle{display:block}
  .hero h1{font-size:30px}
  .hero .tagline{font-size:16px}
  .section{padding:48px 16px}
  .section-title{font-size:26px}
  .footer-grid{grid-template-columns:1fr;gap:24px}
  .page-header h1{font-size:28px}
}