This code does the trick..
textarea:focus{
width: 250px;
position:absolute;
font-size:15px;
height:100px;
background-color: #E7FBF8;
outline: none;
-moz-box-shadow: inset 0 0 5px rgba(0,0,0,0.5);
-webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.5);
box-shadow: inset inset 0 0 5px rgba(0,0,0,0.5);
}