SOURCE

<div class="demoHeader">CSS 属性:</div>
  
<div style="font-size:14px;
            margin:10px;
            font-weight:bold;">align-content:</div>				
				
		<form style="margin:15px;" action="javascript:return false;">
     <input type="hidden" id="preselectedValue" value="space-around" />

      <div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_1" value="stretch" checked='checked' />
  <label for="value_1">stretch</label></div>
					
			<div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_2" value="center" />
  <label for="value_2">center</label></div>
					
			<div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_3" value="flex-start" />
  <label for="value_3">flex-start</label></div>
					
			<div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_4" value="flex-end" />
  <label for="value_4">flex-end</label></div>
					
					<div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_5" value="space-between" /><label for="value_5">space-between</label></div>
					
					<div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_6" value="space-around" /><label for="value_6">space-around</label></div>
					
					<div><input autocomplete="off" type="radio" name="radio_position" onclick="click_position(this)" id="value_7" value="initial" /><label for="value_7">initial</label></div>
								
				</form>
      
      <div id="pfooter"><footer><p><b> 注意:</b> Internet Explorer, Firefox, 和 Safari 浏览器不支持 align-content 属性。</p></footer></div>
      
      
      
      
      
            <div style="width:450px;float:left;">
			
<div class="demoHeader">结果:</div>
	
<div id="demoParent">
        
<div id="demoDIV"><div>
	
  <div id="main">
		<div style="background-color:coral;"></div>
		<div style="background-color:lightblue;"></div>
		<div style="background-color:khaki;"></div>
		<div style="background-color:pink;"></div>
		<div style="background-color:lightgrey;"></div>
		<div style="background-color:lightgreen;"></div>
	</div>
          
</div></div></div>
		
      <div class="demoHeader">CSS 代码:</div>
		  <div id="styleDIV">	div#main<br>		{<br>		display: flex;<br>	  	flex-flow: row wrap;<br>  		align-content:<span id='enlargecssprop'> space-around</span>; <br>		}<br></div></div>
		
<div style="clear:both;"></div>
	

<div class="playitFooter" style="float:left;">点击上面的属性值然后查看效果</div>
	
	
		<div style="clear:both;"></div>
	</div>

body {
            font-family: verdana;
            font-size: 12px;
          }
          
          #playitcontainer {
            width: 974px;
            background-color: #e5eecc;
            border: 1px solid #98bf21;
            margin: auto;
          }
          
          #enlargecssprop {
            font-weight: bold;
            font-size: 14px;
            color: #000000;
          }
          
          #demoDIV {
            margin-left: 10px;
            margin-top: 3px;
            background-color: #ffffff;
            border: 1px solid #c3c3c3;
            height: 280px;
            width: 430px;
          }
          
          div#main {
            display: flex;
            flex-flow: row wrap;
            align-content: space-around;
          }
          
          #styleDIV {
            font-family: courier new;
            margin-left: 10px;
            background-color: #f1f1f1;
            border: 1px solid #c3c3c3;
            width: 424px;
            padding: 3px;
            color: #222222;
          }
          
          div.demoHeader {
            font-size: 14px;
            margin-top: 5px;
            margin-left: 5px;
            margin-bottom: 2px;
            color: #617f10;
          }
          
          div.playitFooter {
            font-size: 24px;
            color: #617f10;
            padding: 10px;
          }
          
          #pfooter {
            margin: 15px;
          }
          
          div#main {
            width: 140px;
            height: 278px;
            border: 1px solid #000000;
          }
          
          div#main div {
            width: 70px;
            height: 70px;