body{margin:0 auto; padding:0; width:100%; min-width:320px;  max-width:640px;}
img{width:100%;}
li{list-style-type:none;}
ul, li{margin:0;padding:0;-webkit-text-size-adjust: none}
p,video{margin:0; padding:0;}
video{max-width:100%; height:auto;}
p{font-size:18px; line-height:32px; letter-spacing:1px; font-family:"微软雅黑";}

@media screen and (max-width:320px){ video{width:320px; height:auto;}}
@media screen and (min-width:330px) and (max-width:480px){ video{width:390px; height:auto;}}
@media screen and (min-width:490px) and (max-width:640px){ video{width:560px; height:auto;}}

.classroom_all{width:100%; margin:0 auto; overflow:hidden;}

@media screen and (max-width:320px){
	p{font-size:9px; line-height:16px; letter-spacing:1px;}
	}
@media screen and (min-width:330px) and (max-width:480px){
	p{font-size:11px; line-height:24px; letter-spacing:1px;}
	}
@media screen and (min-width:490px) and (max-width:640px){
	p{font-size:18px; line-height:32px; letter-spacing:1px;}
	}
.classroom_zero{width:78.28125%; margin:0 auto 4% auto; overflow:hidden;}
.classroom_one{width:78.4375%; margin:4% auto 0 auto; overflow:hidden;}
.classroom_two{width:80.3125%; margin:0 auto; overflow:hidden;}
.classroom_two>p{text-indent: 2em;}
.classroom_three{width:80.3125%; margin:3% auto; overflow:hidden;}
.classroom_four{width:81.875%; margin:3% auto 0 auto; overflow:hidden;}

.teachers_11{width: 66.25%; overflow: hidden; margin:5.1% auto;}
.teachers_11>a{float: left; width: 47%; display: block;}
.teachers_12{width: 96.875%; overflow: hidden; margin: 0 auto 5.1% auto;}