<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<style>
body{display:-webkit-box; -webkit-box-orient:horizontal;}
div{height:100px;}
.div1{background:orange;}
.div2{background:pink;}
.div3{background:red;}
</style>
<body>
<div class="div1"> 盒子1 </div>
<div class="div2"> 盒子2 </div>
<div class="div3"> 盒子3 </div>
</body>
</html>