*{box-sizing:border-box}
body{margin:0;font-family:"Microsoft YaHei",Arial;color:#333}
header{height:70px;display:flex;align-items:center;justify-content:space-between;padding:0 8%;background:#fff;border-bottom:1px solid #eee}
.logo{font-size:24px;font-weight:bold;color:#1261a0}
nav a{text-decoration:none;color:#333;margin:0 12px}
.banner{height:360px;background:linear-gradient(135deg,#1261a0,#35a5e5);color:#fff;text-align:center;padding-top:110px}
.banner h1{font-size:42px}
.container{max-width:1100px;margin:50px auto;padding:20px}
.cards{max-width:1100px;margin:auto;display:flex;gap:20px}
.cards div{flex:1;background:#f4f8fc;padding:30px;text-align:center}
footer{text-align:center;background:#222;color:#fff;padding:25px;margin-top:60px}
@media(max-width:700px){header{height:auto;display:block;padding:20px}nav a{display:inline-block;margin:8px}.cards{display:block}.cards div{margin:15px}}