两个div并排，一个固定宽度，一个自适应
html
<div class="wrap"> <div class="left"></div> <div class="right"></div> </div>
css
方式一：BFC(块级格式化上下文)
.wrap{
width:1000px;
height:400px;
border: 1px solid red;
}
.left{
width:200px;
height:100%;
background: gray;
float: left;
}
.right{
overflow:hidden; /* 触发bfc */
background: green;
height: 100%;
}
方式二：flex布局
.wrap{
width:1000px;
height:400px;
border:1px solid red;
display:flex; /*flex布局*/
}
.left{
width:200px;
height:100%;
background:gray;
flex:none;
}
.right{
height:100%;
background:green;
flex:1; /*flex布局*/
}
方式三：table
.wrap{
width:1000px;
height:400px;
border:1px solid red;
display:table; /*table布局*/
}
.left{
width:200px;
height:100%;
background:gray;
display:table-cell;
}
.right{
height:100%;
background:green;
display: table-cell;
}
方式四：calc计算
.wrap{
width:1000px;
height:400px;
border:1px solid red;
}
.left{
width:200px;
height:100%;
background:gray;
float:left;
}
.right{
height:100%;
background:green;
float:right;
width:calc(100% - 200px);
}
方式五：margin-left
.wrap{
width:1000px;
height:400px;
border:1px solid red;
}
.left{
float:left;
width:200px;
border:1px solid red;
height:100%;
background:gray;
}
.right{
height:100%;
border:1px solid blue;
width:auto;
background:green;
margin-left:200px;
}