One method to create radial gradients is demonstrated below:
#leftshadow
{
margin-left: 10px;
height: 200px;
width: 20px;
border-left:1px solid #ebebeb;
border-left:1px solid rgba(0,0,0,0.4);
background:-webkit-gradient(linear,left top,right top,from(rgba(0,0,0,.3)),to(rgba(0,0,0,0)));
-webkit-mask-box-image:-webkit-gradient(linear,left top,right bottom,color-stop(0.0,rgba(0,0,0,0)),color-stop(0.5,rgba(0,0,0,.8)),color-stop(1.0,rgba(0,0,0,0)));
background-image:-moz-radial-gradient(left,ellipse farthest-side,rgba(0,0,0,.3),rgba(0,0,0,0));
}
Access the jsFiddle demonstration here
An alternate variation is available here
The original solution provided was as follows:
If you want a simpler inset shadow effect, you can utilize this code snippet:
#leftshadow
{
-webkit-box-shadow: inset 5px 0px 5px -2px rgba(0,0,0,0.4);
-moz-box-shadow: inset 5px 0px 5px -2px rgba(0,0,0,0.4);
box-shadow: inset inset 5px 0px 5px -2px rgba(0,0,0,0.4);
}
Preview the corresponding jsFiddle here