解决方法：使用CSS3的弹性布局和border-radius属性
代码如下：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
html,
body {
height: 100%;
background-color: skyblue;
}
ul {
height: 100px;
width: 100px;
border: 1px solid gray;
list-style: none;
padding: 0;
/*兼容处理*/
-webkit-border-radius: 10px;
-moz-border-radius: 10px;
-ms-border-radius: 10px;
-o-border-radius: 10px;
border-radius: 10px;
background-color: #fff;
/*在父元素中开启布局*/
display: flex;
margin: 10px;
float: left;
}
li {
width: 20px;
height: 20px;
background-color: #000;
border-radius: 50%;
margin: 5px;
}
ul:nth-child(2) {
/*设置子元素在横轴的对齐方式*/
-webkit-justify-content: center;
-moz-justify-content: center;
-ms-justify-content: center;
-o-justify-content: center;
justify-content: center;
}
ul:nth-child(3) {
-webkit-justify-content: flex-end;
-moz-justify-content: flex-end;
-ms-justify-content: flex-end;
-o-justify-content: flex-end;
justify-content: flex-end;
}
ul:nth-child(4) {
-webkit-justify-content: flex-end;
-moz-justify-content: flex-end;
-ms-justify-content: flex-end;
-o-justify-content: flex-end;
justify-content: flex-end;
/*设置子元素在纵轴的对齐方式*/
-ms-align-items: center;
align-items: center;
}
ul:nth-child(5) {
-webkit-justify-content: center;
-moz-justify-content: center;
-ms-justify-content: center;
-o-justify-content: center;
justify-content: center;
-ms-align-items: center;
align-items: center;
}
ul:nth-child(6) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
}
ul:nth-child(7) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
}
ul:nth-child(7) li:nth-child(2) {
/*设置子元素自身在纵轴的对齐方式*/
-ms-align-self: flex-end;
align-self: flex-end;
}
ul:nth-child(8) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
}
ul:nth-child(8) li:nth-child(2) {
-ms-align-self: center;
align-self: center;
}
ul:nth-child(8) li:nth-child(3) {
-ms-align-self: flex-end;
align-self: flex-end;
}
ul:nth-child(9) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
/*开启弹性布局后，默认方向是横着放，可以改变其摆放方式*/
-webkit-flex-direction: column;
-moz-flex-direction: column;
-ms-flex-direction: column;
-o-flex-direction: column;
flex-direction: column;
}
ul:nth-child(10) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
/*弹性布局默认一行排布，子元素过多时，其宽度会发生变化*/
-webkit-flex-wrap: wrap;
-moz-flex-wrap: wrap;
-ms-flex-wrap: wrap;
-o-flex-wrap: wrap;
flex-wrap: wrap;
}
ul:nth-child(10) li:nth-child(3) {
margin-right: 20px;
-ms-align-self: flex-end;
align-self: flex-end;
}
ul:nth-child(10) li:nth-child(4) {
-ms-align-self: flex-end;
align-self: flex-end;
}
ul:nth-child(11) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
-webkit-flex-wrap: wrap;
-moz-flex-wrap: wrap;
-ms-flex-wrap: wrap;
-o-flex-wrap: wrap;
flex-wrap: wrap;
/*开启换行后，align-items和align-self失去效果，但align-content可以调整其在纵轴的对齐方式*/
-webkit-align-content: space-between;
-moz-align-content: space-between;
-ms-align-content: space-between;
-o-align-content: space-between;
align-content: space-between;
}
ul:nth-child(11) li:nth-child(3) {
margin: 0 40px;
}
ul:nth-child(12) {
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
-webkit-flex-wrap: wrap;
-moz-flex-wrap: wrap;
-ms-flex-wrap: wrap;
-o-flex-wrap: wrap;
flex-wrap: wrap;
-webkit-align-content: space-between;
-moz-align-content: space-between;
-ms-align-content: space-between;
-o-align-content: space-between;
align-content: space-between;
}
</style>
</head>
<body>
<ul>
<li></li>
</ul>
<ul>
<li></li>
</ul>
<ul>
<li></li>
</ul>
<ul>
<li></li>
</ul>
<ul>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</html>
