rem响应式--初步认知
设置根元素
html{
font-size: 10px;
}
body{
font-size: 1.6rem;
}
#box1{
width: 20rem;
height: 30rem;
background-color: red;
}
#box2{
width: 25rem;
height: 15rem;
background-color: greenyellow;
}
