CSS左侧固定

<style>
    .left{
        width: 200px;
        float: left;
        background-color: pink;
    }
    .right{
        overflow:hidden;
        background-color: lightskyblue;
    }
</style>
<div class="left">左侧固定宽度</div>
<div class="right">右边自动填满</div>