I'm making a small webpage where the I would like the top banner with some text to remain on top, as such:

HTML:

<div id = "topBanner">

    <h1>Some Text</h1>

</div>

CSS:

#topBanner{
    position:fixed;

    background-color: #CCCCCC;
    width: 100%;
    height:200px;

    top:0;
    left:0;

    z-index:900;

    background: -moz-linear-gradient(top,  rgba(204,204,204,0.65) 0%, rgba(204,204,204,0.44) 32%, rgba(204,204,204,0.12) 82%, rgba(204,204,204,0) 100%); /* FF3.6+ */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(204,204,204,0.65)), color-stop(32%,rgba(204,204,204,0.44)), color-stop(82%,rgba(204,204,204,0.12)), color-stop(100%,rgba(204,204,204,0))); /* Chrome,Safari4+ */
    background: -webkit-linear-gradient(top,  rgba(204,204,204,0.65) 0%,rgba(204,204,204,0.44) 32%,rgba(204,204,204,0.12) 82%,rgba(204,204,204,0) 100%); /* Chrome10+,Safari5.1+ */
    background: -o-linear-gradient(top,  rgba(204,204,204,0.65) 0%,rgba(204,204,204,0.44) 32%,rgba(204,204,204,0.12) 82%,rgba(204,204,204,0) 100%); /* Opera 11.10+ */
    background: -ms-linear-gradient(top,  rgba(204,204,204,0.65) 0%,rgba(204,204,204,0.44) 32%,rgba(204,204,204,0.12) 82%,rgba(204,204,204,0) 100%); /* IE10+ */
    background: linear-gradient(to bottom,  rgba(204,204,204,0.65) 0%,rgba(204,204,204,0.44) 32%,rgba(204,204,204,0.12) 82%,rgba(204,204,204,0) 100%); /* W3C */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#a6cccccc', endColorstr='#00cccccc',GradientType=0 ); /* IE6-9 */


}
/*WebPage Header*/
h1{
    font-size:3em;
    color:blue;
    text-shadow:#CCCCCC 2px 2px 2px, #000 0 -1px 2px;

    position: absolute;
    width: 570px;

    left:50%;
    right:50%;
    line-height:20px;

    margin-left: -285px;

    z-index:999;
}

The z-index works fine, except that because I'm using a gradient any time I scroll down the elements behind the banner are still visible, albeit somewhat transparent.

Is there any way to make them total invisible? i.e., what I'm trying to do is make it as though the banner is a solid color, even though it's a gradient.

Thanks in advance for any help!