Fade out elements on WebKit and Firefox and IE 9+

gistfile1.html

<style>
#mask_demo {
  background: #d0d0d0;
  width: 80%;
  padding: 10px;
  position: relative;
}

/* this may not be a better way to do it, but it is a different way.
   it still used the svg for the background on browsers that don't
   support gradients all that well, but it is all in the css
*/
#mask_demo:after {
  position: absolute;
  left: 0; 
  top: 0;
  width: 100%;
  height: 100%;
  content: '';
  /* gradient from www.colorzilla.com/gradient-editor/ */
  /* IE9 SVG, needs conditional override of 'filter' to 'none' */
background: url(data:image/svg+xml;base64,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);
background: -moz-linear-gradient(left, rgba(255,255,255,0) 0%, rgba(255,255,255,0) 75%, rgba(255,255,255,1) 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, right top, color-stop(0%,rgba(255,255,255,0)), color-stop(75%,rgba(255,255,255,0)), color-stop(100%,rgba(255,255,255,1))); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(left, rgba(255,255,255,0) 0%,rgba(255,255,255,0) 75%,rgba(255,255,255,1) 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(left, rgba(255,255,255,0) 0%,rgba(255,255,255,0) 75%,rgba(255,255,255,1) 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(left, rgba(255,255,255,0) 0%,rgba(255,255,255,0) 75%,rgba(255,255,255,1) 100%); /* IE10+ */
background: linear-gradient(to right, rgba(255,255,255,0) 0%,rgba(255,255,255,0) 75%,rgba(255,255,255,1) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00ffffff', endColorstr='#ffffff',GradientType=1 ); /* IE6-8 */
}
</style>


<!--[if gte IE 9]>
<style type="text/css">
  .gradient { filter: none; }
</style>
<![endif]-->

<div id="mask_demo">
Bacon ipsum dolor sit amet pig capicola flank drumstick tri-tip cow pork. Tenderloin pork belly ham cow chuck strip steak andouille fatback beef ribs. Tongue jowl pig chicken flank drumstick pancetta strip steak capicola biltong. Swine jowl beef ribs filet mignon spare ribs, beef bresaola tail venison pork loin pancetta prosciutto meatloaf fatback turkey. Bresaola turducken beef ribs ribeye salami chicken hamburger meatloaf. T-bone spare ribs rump, strip steak tongue sirloin biltong capicola corned beef bresaola. Swine ham tail filet mignon t-bone flank.
</div>