Like this: http://codepen.io/richbradshaw/pen/uexaG
.blurred-line {
height:30px;
width:600px;
margin:0 auto;
-moz-background-image: linear-gradient(to right, transparent 0%, black 100%);
background-image: linear-gradient(to right, transparent 0%, black 100%);
border-radius:15px;
-webkit-filter:blur(1px);
}
Which renders like:
Despite what most people seem to think, that gradient syntax is the real syntax, and works in Firefox 10+, Chrome 26+, IE10+ and Safari 6 (or 7?)+.
Including all the ancient gradient stuff is a waste of time, unless you are planning to support browsers that don't exist (e.g. Chrome 10, Firefox 3.6).