子元素的宽度超出父元素了怎么办啊？ .top{width:1000px;height:50px;} .main{background:red; width:1000px; height:400px;} .left{background:blue;position:absolute; width:200px; height:400px;} .right{background:green; height:400px; position:absolute; margin-left:210px; width:70%;} .foot{; width:1000px; height:50px;}