*{box-sizing:border-box}body{margin:0;background:#f5f7fb;color:#172033;font-family:Tahoma,Arial,sans-serif;padding-bottom:78px}a{text-decoration:none;color:inherit}.topbar{height:70px;background:#fff;border-bottom:1px solid #e5e9f0;display:flex;align-items:center;justify-content:space-between;padding:0 6%;position:sticky;top:0;z-index:5}.brand{display:flex;align-items:center;gap:10px}.brand b,.brand small{display:block}.brand small{font-size:11px;color:#687386;margin-top:3px}.mark{width:40px;height:40px;background:#2563eb;color:#fff;border-radius:12px;display:grid;place-items:center;font-weight:bold;font-size:22px}.install{border:0;border-radius:10px;padding:9px 13px;background:#eef4ff;color:#2563eb;font-weight:bold}.hidden{display:none!important}#app{max-width:1100px;margin:auto;padding:28px 18px}.hero{padding:48px 36px;border-radius:24px;background:#2563eb;color:white;box-shadow:0 15px 40px #2563eb22}.hero h1{font-size:42px;margin:12px 0}.hero p{line-height:2;max-width:700px;color:#eaf1ff}.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}.btn{display:inline-flex;padding:11px 16px;border-radius:11px;font-weight:bold}.primary{background:#fff;color:#17449c}.ghost{background:#edf2f8;color:#263247}.section{margin-top:30px}.head{display:flex;justify-content:space-between;align-items:center}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;margin-top:18px}.card,.course,.notice,.empty{background:#fff;border:1px solid #e4e8ef;border-radius:18px;padding:20px}.card b,.card small{display:block}.card small{color:#687386;line-height:1.8;margin-top:8px}.course span{font-size:11px;color:#2563eb;background:#edf4ff;padding:6px 9px;border-radius:20px}.icon{font-size:38px;margin-bottom:12px}.course p,.muted{color:#687386;line-height:1.8}.empty{text-align:center;color:#687386;padding:45px}.notice{line-height:2;color:#566174;margin-top:18px}.nav{position:fixed;bottom:0;left:0;right:0;height:70px;background:#fff;border-top:1px solid #e4e8ef;display:flex;justify-content:center;z-index:10}.nav a{width:150px;display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:18px;gap:3px}.nav span{font-size:11px;color:#687386}@media(max-width:600px){.topbar{padding:0 14px}.hero{padding:34px 22px}.hero h1{font-size:32px}.nav a{font-size:16px}.nav span{font-size:10px}}
*{box-sizing:border-box}
body{margin:0;background:#f5f7fb;color:#172033;font-family:Tahoma,Arial,sans-serif;padding-bottom:60px}
a{text-decoration:none;color:inherit}
.topbar{height:60px;background:#fff;border-bottom:1px solid #e5e9f0;display:flex;align-items:center;justify-content:space-between;padding:0 6%;position:sticky;top:0;z-index:5;box-shadow:0 2px 8px rgba(0,0,0,0.03)}
.brand{display:flex;align-items:center;gap:10px}
.mark{width:36px;height:36px;background:#2563eb;color:#fff;border-radius:10px;display:grid;place-items:center;font-weight:bold;font-size:20px}
#app{max-width:1100px;margin:auto;padding:20px 18px;min-height:calc(100vh - 140px)}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:16px;margin-top:18px}
.card,.course{background:#fff;border:1px solid #e4e8ef;border-radius:16px;padding:20px;transition:transform 0.2s,box-shadow 0.2s;position:relative}
.card:hover{transform:translateY(-4px);box-shadow:0 8px 25px rgba(37,99,235,0.08)}
.icon{font-size:40px;margin-bottom:12px;display:block}
h3{margin:8px 0;font-size:18px}
.empty{text-align:center;color:#687386;padding:45px;background:#fff;border-radius:16px;border:1px solid #e4e8ef}
.nav{position:fixed;bottom:0;left:0;right:0;height:60px;background:#fff;border-top:1px solid #e4e8ef;display:flex;justify-content:center;z-index:10;box-shadow:0 -2px 10px rgba(0,0,0,0.03)}
.nav a{flex:1;max-width:120px;display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:16px;gap:2px;color:#687386;transition:color 0.2s}
.nav a:hover{color:#2563eb}
.nav span{font-size:10px;font-weight:bold}
@media(max-width:600px){.topbar{padding:0 14px}.nav a{font-size:14px}.nav span{font-size:9px}}