CSS3媒体查询实例

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8"> 
  <title>菜鸟教程(runoob.com)</title> 
<style>
ul {
    list-style-type: none;
}

ul li a {
    color: green;
    text-decoration: none;
    padding: 3px; 
    display: block;
}

@media screen and (max- 639px){
    ul li a {
      padding-left: 30px;
      color:red;
    }
}

@media screen and (max- 819px) and (min- 640px) {
    ul li a {
      padding-left: 30px;
      color:green;
    }
}

@media screen and (max- 1019px) and (min- 820px) {
    ul li a {
      padding-left: 30px;
      color:yellow;
    }
}

@media screen and (min- 1020px) {
    ul li a {
      padding-left: 30px;
      color:pink;
    }
}
</style>
</head>
<body>
  <h1>重置浏览器窗口,查看效果!</h1>
  <ul>
    <li><a data-email="johndoe@example.com" href="mailto:johndoe@example.com">John Doe</a></li>
    <li><a data-email="marymoe@example.com" href="mailto:marymoe@example.com">Mary Moe</a></li>
    <li><a data-email="amandapanda@example.com" href="mailto:amandapanda@example.com">Amanda Panda</a></li>
  </ul>
</body>
</html>