.head{background:linear-gradient(to bottom,#09488a,#1264ba);}
.head.on{position:fixed; top:-28px; width: 100%;  z-index: 10;}
.head.on .head-top{padding-top:20px;}
.head::before{position:absolute;bottom:100%;left:0;width:100%;height:100%;background:#fff;box-shadow:0 0 10px rgba(0,0,0,.2);content:"";transition:all .5s;}
.head.on::before{bottom:0;}
.head-top{position:relative;line-height:84px;}
.head.on .logo { display: none;}
.head.on .nav>ul>li>a{color:#333;}
.head.on .nav-r a{border-color:#333;color:#333;}
.head.on .nav-r a img{display:inline-block;}
.head.on .nav-r a img:first-child{display:none;}
.banner .slick-dots { display: none;}
.art-body  { min-height: 400px;}