css之页面两列布局

 <div class="left"></div>
 <div class="right"></div>

.left {
      position: absolute; /*这可以换成float:left,都可以使其脱离文档流*/
      height: 100px;
      width: 300px;
      background-color: blue;
 }
.right {
     height: 200px;
     margin-left: 300px;
     background-color: red;
 }

.left {
         float: left;
         height: 200px;
          width: 300px;
          background-color: blue;
}
.right {
          overflow: auto;
          height: 200px;
　　　　　　background-color:red;

}