*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:"Microsoft YaHei",sans-serif;
}
ul{
    list-style:none;
}
a{
    text-decoration:none;
    color:inherit;
}
.container{
    width:1200px;
    max-width:92%;
    margin:0 auto;
}
/*导航栏*/
.header{
    background:#fff;
    box-shadow:0 2px 10px rgba(0,0,0,0.08);
    position:sticky;
    top:0;
    z-index:999;
}
.nav-wrap{
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:12px 0;
}
.logo img{
    width:220px;
    height:auto;
    object-fit:contain;
}
.nav-list{
    display:flex;
    gap:32px;
}
.nav-list li a{
    font-size:16px;
    color:#333;
}
.nav-list li a:hover{
    color:#0077bb;
}
.menu-btn{
    font-size:28px;
    display:none;
    cursor:pointer;
}
/*banner首屏*/
.banner{
    height:520px;
    background:linear-gradient(135deg,#1b5b8c,#2788bc);
    display:flex;
    align-items:center;
}
.banner-text{
    color:#fff;
}
.banner-text h1{
    font-size:56px;
    margin-bottom:16px;
}
.banner-text p{
    font-size:22px;
    opacity:0.9;
}
/*通用区块*/
.section{
    padding:70px 0;
}
.bg-gray{
    background:#f7f9fa;
}
.title-box{
    text-align:center;
    margin-bottom:40px;
}
.title-box h2{
    font-size:32px;
    color:#222;
    margin-bottom:10px;
}
.title-box p{
    color:#666;
}
/*四列卡片*/
.four-col-wrap{
    display:grid;
    grid-template-columns: repeat(4,1fr);
    gap:24px;
}
/*三列卡片*/
.three-col-wrap{
    display:grid;
    grid-template-columns: repeat(3,1fr);
    gap:24px;
}
.info-card{
    background:#fff;
    padding:28px;
    border-radius:10px;
    box-shadow:0 2px 12px rgba(0,0,0,0.06);
}
.info-card h3{
    font-size:20px;
    margin-bottom:12px;
    color:#222;
}
.info-card p{
    color:#555;
    line-height:1.7;
    margin-bottom:16px;
}
.btn{
    display:inline-block;
    padding:9px 20px;
    background:#0077bb;
    color:#fff;
    border-radius:6px;
}
.btn:hover{
    background:#005f96;
}
/*页脚footer*/
.footer{
    background:#222;
    color:#ccc;
    padding:45px 0 20px;
}
.footer-content{
    display:grid;
    grid-template-columns: repeat(3,1fr);
    gap:30px;
    margin-bottom:30px;
}
.footer-box h3{
    color:#fff;
    margin-bottom:14px;
}
.footer-box a{
    color:#a9d7f5;
}
.copyright a {
    color:#72b8ee;
    text-decoration:none;
    transition:0.25s;
}
.copyright a:hover {
    color:#ffffff;
    text-decoration:underline;
}

/*返回顶部*/
.back-top{
    width:44px;
    height:44px;
    background:#0077bb;
    color:#fff;
    text-align:center;
    line-height:44px;
    border-radius:50%;
    position:fixed;
    bottom:30px;
    right:30px;
    cursor:pointer;
    font-size:20px;
}
/*移动端适配*/
@media(max-width:992px){
    .four-col-wrap{
        grid-template-columns: repeat(2,1fr);
    }
}
@media(max-width:768px){
    .nav-list{
        display:none;
    }
    .menu-btn{
        display:block;
    }
    .four-col-wrap,.three-col-wrap{
        grid-template-columns:1fr;
    }
    .footer-content{
        grid-template-columns:1fr;
    }
    .banner-text h1{
        font-size:40px;
    }
    .back-top{
        display:none;
    }
}
.nav-list.show{
    display:flex;
    flex-direction:column;
    position:absolute;
    top:80px;
    left:0;
    width:100%;
    background:#fff;
    padding:20px;
    box-shadow:0 4px 8px #00000015;
}