Try it Yourself - CSS Reference order

<!DOCTYPE html>
<html>
<head>
<style>
#main {
   width: 400px;
   height: 150px;
   border: 1px solid #c3c3c3;
   display: -webkit-flex; /* Safari */
   display: flex;
}

#main div {
   width: 70px;
   height: 70px;
}

/* Safari 6.1+ */
div#myRedDIV {-webkit-order: 2;}
div#myBlueDIV {-webkit-order: 4;}
div#myGreenDIV {-webkit-order: 3;}
div#myPinkDIV {-webkit-order: 1;}

/* Standard syntax */
div#myRedDIV {order: 2;}
div#myBlueDIV {order: 4;}
div#myGreenDIV {order: 3;}
div#myPinkDIV {order: 1;}
</style>
</head>
<body>

<div id="main">
  <div style="background-color:coral;" id="myRedDIV"></div>
  <div style="background-color:lightblue;" id="myBlueDIV"></div>
  <div style="background-color:lightgreen;" id="myGreenDIV"></div>
  <div style="background-color:pink;" id="myPinkDIV"></div>
</div>

<p><b>Note:</b> Internet Explorer 10 and earlier versions do not support the order property.</p>

<p><b>Note:</b> Safari 6.1 (and newer) supports an alternative, the -webkit-order property.</p>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<style> 
#main {
    width: 400px;
    height: 150px;
    border: 1px solid #c3c3c3;
    display: -webkit-flex; /* Safari */
    display: flex;
}

#main div {
    width: 70px;
    height: 70px;
}

/* Safari 6.1+ */
div#myRedDIV   {-webkit-order: 2;}
div#myBlueDIV  {-webkit-order: 4;}
div#myGreenDIV {-webkit-order: 3;}
div#myPinkDIV  {-webkit-order: 1;}

/* Standard syntax */
div#myRedDIV   {order: 2;}
div#myBlueDIV  {order: 4;}
div#myGreenDIV {order: 3;}
div#myPinkDIV  {order: 1;}
</style>
</head>
<body>

<p><b>Note:</b> Internet Explorer 10 and earlier versions do not support the order property.</p>

<p><b>Note:</b> Safari 6.1 (and newer) supports an alternative, the -webkit-order property.</p>

</body>
</html>