Flexbox实现垂直水平居中

<style type="text/css">
.container{border:1px solid red; height:200px;
display: flex; justify-content: center; align-items: center; text-align:center;
}
</style>
<div class="container">
<img src="http://pic.cnitblog.com/face/340216/20131017185242.png" alt="fireworks">
</div>