效果：
代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
*{
margin: 0px;
padding: 0px;
}
body{
height: 100%;
width: 100%;
}
#main{
height: 720px;
width: 100%;
background-color: pink;
}
button{
height: 15px;
width: 15px;
border: 1px solid #fff;
margin: 10px 10px;
}
#red{
background-color: red;
}
#green{
background-color: green;
}
#blue{
background-color: blue;
}
</style>
</head>
<body>
<div id="main">
<button type="button" id="red" onclick="red()"></button>
<button type="button" id="green" onclick="green()"></button>
<button type="button" id="blue" onclick="blue()"></button>
</div>
<script type="text/javascript">
var x=document.getElementById('main');
function red(){
x.style.backgroundColor='red';
document.getElementById('red').style.border="3px solid white";
document.getElementById('green').style.border="1px solid white";
document.getElementById('blue').style.border="1px solid white";
}
function green(){
x.style.backgroundColor='green';
document.getElementById('green').style.border="3px solid white";
document.getElementById('red').style.border="1px solid white";
document.getElementById('blue').style.border="1px solid white";
}
function blue(){
x.style.backgroundColor='blue';
document.getElementById('blue').style.border="3px solid white";
document.getElementById('red').style.border="1px solid white";
document.getElementById('green').style.border="1px solid white";
}
</script>
</body>
</html>
