CSS 圆角怎么用

#test2 {
    width: 100px;
    height: 100px;
    border-radius: 25px;
    background-color: rebeccapurple;
}

#test2 {
    width: 100px;
    height: 100px;
    border-radius: 50px;
    background-color: rebeccapurple;
}

 如果使用百分比，基数就是元素的offsetWidth

#test2 {
    width: 100px;
    height: 100px;
    border-width: 10px;
    border-color: black;
    border-radius: 50%;
    border-style: solid;
}