<style>
#flex-demo {
width: 300px;
height: 300px;
border: 1px solid black;
display: -webkit-flex; /* Safari */
display: flex;
}
#flex-demo div {
-webkit-flex: 1; /* Safari 6.1+ */
-ms-flex: 1; /* IE 10 */
flex: 1;
}
</style>
</head>
<body>
<h1>The flex Property</h1>
<div id="flex-demo">
<div style="background-color:blue; color:#fff;">RED</div>
<div style="background-color:maroon; color:yellow;">BLUE</div>
<div style="background-color:green; color:#fff;">Green div with more content.</div>
</div>
</body>
</html>