.clearfix{display:block;clear:both;float:none;}
/* body{ display: block; margin: 0; padding: 0; font-family: 'Roboto', sans-serif; background-color: #121212; }

nav{display:block;background:#f2f2f2;padding:20px;}
nav h2{display:block;float:left;color:#2b2b2b;text-decoration:none;margin:0;padding:0;}
nav ul{display:block;float:right;list-style:none;margin:0;padding:0;margin-top:5px;}
nav ul li{display:block;float:left;margin-left:20px;}
nav ul li a{color:#5ba9e2;text-decoration:none;}
nav ul li a:hover{text-decoration:underline;} */

.video-back{display:block;/* padding:200px 0px; */text-align:center;background:url(../img/bkspic.jpg) #000;background-size: cover;background-repeat: no-repeat;background-repeat: no-repeat; z-index: 0;}
.video-back h1{display:block;text-align:center;color:#fff;font-size:50px;}
.video-back p{display:block;color:#fff;margin:0px;padding:0px;margin-bottom:20px;}
.video-back img{width:150px;}

.main-heading{text-align: center;margin: 50px auto;font-size: 70px;}
.main-para{margin: 10px 100px;text-align: center; font-size: 20px;}
.jq22-demo a{ color: aliceblue; font-family: "微软雅黑"; font-size: 20px; text-decoration: none; padding-left: 10px;
 padding-right: 10px; font-weight: bold;text-shadow:2px 2px 4px #000; }