CSS for this menu –

<style>
.accordion div
{
background-color:#9CF;
width:100px;
float:left;
-webkit-transition: width 1s ease;
-moz-transition:width 1s ease;
font-family:Georgia, "Times New Roman", Times, serif;
overflow:hidden;
height:50px;

}
.accordion p:first-child
{
padding:10px;
[...]