w1020/7_阶段复习/main.css

div{
    color: red;
    float: none;
}
#box{
    color: blue !important;
    height: 200px;
    width: 200px;
    border:1px solid red;
    text-align: center;
    font-size: 40px;
}
#box:hover{
    font-weight: bolder;
}
#box::after{
    /* content: "hello"; */
}
span{
    text-align: center;
    border-width: 1px;
    border-style: solid;
    border-color: red;
}