<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
*{margin: 0padding: 0}
ul,li{list-style: none}
.box{
width: 600px
height: 600px
position: relative
margin-top: 30%
}
.round1{
position: absolute
top: 0
left: 0
width: 100%
height: 100%
border-radius: 100%
background: #b9d1f5
border: 1px solid #808aa2
overflow: hidden
z-index: 10
}
.round1 .child{
position: absolute
top: 0
left: 0
width: 50%
height: 100%
background: rgba(0,0,0,0)
border: #808aa2 1px solid
}
.round1 .child:nth-child(1){
transform-origin:100% 50%
transform: rotate(30deg)
z-index: 8
}
.round1 .child:nth-child(2){
transform-origin:100% 50%
transform: rotate(60deg)
z-index: 8
}
.round1 .child:nth-child(3){
transform-origin:100% 50%
transform: rotate(90deg)
z-index: 8
}
.round1 .child:nth-child(4){
transform-origin:100% 50%
transform: rotate(120deg)
z-index: 8
}
.round1 .child:nth-child(5){
transform-origin:100% 50%
transform: rotate(150deg)
z-index: 8
}
.round2{
position: absolute
top: 12.5%
left: 12.5%
width: 75%
height: 75%
border-radius: 100%
background: #b3b0fb
border: 1px solid #808aa2
z-index: 100
}
.round3{
position: absolute
top: 25%
left: 25%
width: 50%
height: 50%
border-radius: 100%
background: #ebbbff
border: 1px solid #808aa2
z-index: 200
}
.round4{
position: absolute
top: 37.5%
left: 37.5%
width: 25%
height: 25%
border-radius: 100%
background: #ff91e5
border: 1px solid #2c8a33
z-index: 300
}
</style>
</head>
<body>
<div class="box">
<!---->
<div class="round1">
<div class="child"></div>
<div class="child"></div>
<div class="child"></div>
<div class="child"></div>
<div class="child"></div>
<div class="child"></div>
</div>
<!---->
<!---->
<div class="round2">
</div>
<!---->
<!---->
<div class="round3">
</div>
<!---->
<!---->
<div class="round4">
</div>
<!---->
</div>
</body>
</html>
padding是内边距，块级元素边框内元素和边框之间的距离，padding-left就是指定这个元素内的直接子元素的边框距离该元素内边框的距离。就好比同心圆的圆环宽度。 305px是距离单位。\9是错误写法。<style>html,body {margin:0 padding:0 overflow:hidden}
section {width:100vw height:100vw}
div {width:calc(100% - 5vw) height:calc(100% - 5vw) padding:2vw border:0.5vw solid black border-radius:50%}
</style>
<section></section>
<script>
window.onload=function(){
var divs=document.getElementsByTagName("section")[0]
for(var i=0i<20i++){
divs.appendChild(document.createElement("div"))
divs=divs.firstChild
}
}
</script>
