css怎么实现响应式布局

    

        
left
        
中间
        
right
    

.box{
    width: 100%
    height: 100px;
    display: flex;
}
.left{
    width: 300px;
    background-color: purple;
}
.center{
    flex: 1;
    background-color: pink;
}
.right{
    width: 300px;
    background-color: burlywood;
}

.box{
    position: relative;
    width: 100%;
    height: 100px;
}
.left{
    position: absolute;
    left: 0px;
    width: 300px;
    background-color: pink;
}
.right{
    position: absolute;
    right: 0px;
    width: 300px;
    background-color: pink;
}
.center{
    position: absolute;
    left: 300px;
    right: 300px;
    background-color: burlywood;
}
@media (max-width: 600px){
    .left,.right{
       /* 平分屏幕 */
        width: 50%;
    }
}

.box{
    display: grid;
    grid-template-columns: 300px 1fr 300px;
    grid-template-rows: 100px;
}
.left,.right{
    background-color: pink;
}
.center{
    background-color: burlywood;
}

    
left
    
right
    
center

.box{
    height: 200px;
}
.left{
    float: left;
    width: 300px;
    background-color: pink;
}
.right{
    float: right;
    width: 300px;
    background-color: pink;
}
.center{
    margin:0 300px;
    background-color: burlywood;
}

@media (max-width: 600px){
      .left,.right{
        width: 50%;
    }
    .center{
        opacity: 0;
    }
}