* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", sans-serif;
}
body {
    background-color: #f8f9fa;
    color:#333;
    line-height:1.7;
}
.container {
    max-width:1200px;
    margin:0 auto;
    padding:0 20px;
}
header {
    background:#ffffff;
    box-shadow:0 2px 8px rgba(0,0,0,0.06);
}
.nav-wrap {
    display:flex;
    justify-content:space-between;
    align-items:center;
    height:70px;
}
.logo {
    font-size:22px;
    font-weight:bold;
    color:#2563eb;
}
.nav a {
    margin-left:28px;
    text-decoration:none;
    color:#444;
    transition:0.25s;
}
.nav a:hover {
    color:#2563eb;
}
.nav a.active {
    color:#2563eb;
    font-weight:500;
}
.banner {
    background:#eef4fc;
    padding:90px 0;
    text-align:center;
}
.banner h1 {
    font-size:38px;
    margin-bottom:16px;
    color:#1e293b;
}
.banner p {
    font-size:17px;
    color:#555;
    max-width:720px;
    margin:0 auto 30px;
}
.btn {
    display:inline-block;
    padding:12px 30px;
    background:#2563eb;
    color:#fff;
    text-decoration:none;
    border-radius:6px;
}
.btn:hover {
    background:#1d4ed8;
}
.section {
    padding:70px 0;
}
.section-title {
    text-align:center;
    font-size:30px;
    margin-bottom:45px;
}
.grid3 {
    display:grid;
    grid-template-columns:repeat(3,1fr);
    gap:26px;
}
.card {
    background:#fff;
    padding:28px;
    border-radius:10px;
    box-shadow:0 2px 12px rgba(0,0,0,0.05);
}
.card h3 {
    margin-bottom:12px;
    color:#222;
}
footer {
    background:#1e293b;
    color:#cbd5e1;
    text-align:center;
    padding:35px 0;
    margin-top:20px;
}
/* 适配手机 */
@media(max-width:768px){
    .nav-wrap{flex-direction:column;height:auto;padding:15px 0;}
    .nav a{margin:0 10px;}
    .grid3{grid-template-columns:1fr;}
    .banner h1{font-size:28px;}
}