<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <script src="https://cdn.bootcss.com/jquery/1.12.4/jquery.js"></script> <style> a{ display: block; float: left; margin: 50px; width: 100px; height: 100px; line-height: 100px; text-decoration: none; text-align: center; color: #fff; border-radius: 50%; } </style> </head> <body> <a href="">1</a> <a href="">2</a> <a href="">3</a> <a href="">4</a> <script> // 改变标签的背景颜色 function changeBg(tag){ var len = document.getElementsByTagName(tag).length; for(var i=0;i<len;i++){ document.getElementsByTagName(tag)[i].style.background = 'rgb(' +Math.floor(Math.random()*256)+','+Math.floor(Math.random()*256)+','+Math.floor(Math.random()*256)+')'; } } $(function(){ changeBg('a'); $('a').hover(function(){ // 获取当前的背景色 $bg = $(this).css('background-color'); $(this).css('box-shadow','0px 0px 20px '+$bg); $(this).css('border-radius', '20px'); },function(){ $(this).css('box-shadow','none'); $(this).css('border-radius', '50%'); }) }) </script> </body> </html>