参考：https://juejin.cn/post/6973562604581027853
圣杯布局是通过float搭建布局+margin使三列布局到一行上+relative相对定位调整位置。
双飞翼布局是通过float+margin，没有使用相对定位。
圣杯布局
<style>
* {
padding: 0;
margin: 0;
text-align: center;
}
html{
height: 100%;
}
body{
display: flex;
flex-direction: column;
height: 100%;;
}
.header{
width: 100%;
height: 50px;
background-color:dimgray;
}
.footer{
width: 100%;
height: 50px;
background-color:dimgray;
}
.outer{
flex:1;
padding-left: 100px;
padding-right: 200px;
}
.center{
float: left;
background-color: darkslateblue;
height: 100%;
width: 100%;
}
.left{
float: left;
width: 100px;
margin-left: -100%;
background-color: burlywood;
height: 100%;
position: relative;
left: -100px;
}
.right{
float: left;
width: 200px;
margin-left: -200px;
height: 100%;
position: relative;
right: -200px;
background-color: cyan;
}
</style>
<body>
<div class="header">header</div>
<div class="outer">
<div class="center">center</div>
<div class="left">left</div>
<div class="right">right</div>
</div>
<div class="footer">footer</div>
</body>双飞翼布局
<style>
*{
padding: 0;
margin: 0;
}
html{
width: 100%;
height: 100%;
text-align: center;
}
body{
display: flex;
width: 100%;
height: 100%;
flex-direction: column;
}
.header{
background-color:grey;
height: 50px;
}
.footer{
background-color:grey;
height: 50px;
}
.outer{
flex:1;
}
.center{
float: left;
width: 100%;
background-color: darkslateblue;
height: 100%;
}
.left{
float: left;
margin-left: -100%;
width: 100px;
background-color: burlywood;
height: 100%;
}
.right{
float: left;
width: 200px;
background-color: cyan;
margin-left: -200px;
height: 100%;
}
.content{
margin-left: 100px;
margin-right: 200px;
height: 100%;
}
</style>
<body>
<div class="header">header</div>
<div class="outer">
<div class="center">
<div class="content">content</div>
</div>
<div class="left">left</div>
<div class="right">right</div>
</div>
<div class="footer">footer</div>
</body>