/* 手机自适应 */
@media (max-width:768px){
    .header {height:auto;padding:15px;flex-wrap:wrap;}
    .nav {margin-top:10px;}
    .nav a {display:inline-block;margin:5px 8px;}
    .banner {height:200px;}
    .banner-text h1 {font-size:22px;}
    .section {width:100%;}
}