console
<div class="container1">
<div class="box1">左边固定1</div>
<div class="box2"></div>
</div>
<div class="container2">
<div class="box3">左边固定2</div>
<div class="box4"></div>
</div>
.container1 {
position: relative;
top: 50px;
margin: 0 20px;
height: 300px;
}
.box1 {
position: absolute;
left: 0;
width: 400px;
height: 300px;
background-color: #ED3E3E;
line-height: 300px;
font-size: 36px;
}
.box2 {
position: absolute;
top: 0;
bottom: 0;
left: 400px;
right: 0;
background-color: #43BC60;
}
.container2 {
height: 300px;
margin: 100px 20px;
}
.box3 {
float: left;
width: 400px;
height: 300px;
background-color: #a6c1ff;
line-height: 300px;
font-size: 36px;
}
.box4 {
float: right;
width: calc(100% - 400px);
height: 300px;
background-color: #FA7D3C;
}