в зависимости от того, что вы хотите, что-то подобное может работать;
<style>
height: 100%;
width: 100%;
/* IE9 SVG, needs conditional override of 'filter' to 'none' */
background: url(data:image/svg+xml;base64,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);
background: -moz-radial-gradient(center, ellipse cover, rgba(0,0,0,0) 0%, rgba(0,0,0,0) 63%, rgba(0,0,0,0.65) 99%, rgba(0,0,0,0.65) 100%); /* FF3.6+ */
background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%,rgba(0,0,0,0)), color-stop(63%,rgba(0,0,0,0)), color-stop(99%,rgba(0,0,0,0.65)), color-stop(100%,rgba(0,0,0,0.65))); /* Chrome,Safari4+ */
background: -webkit-radial-gradient(center, ellipse cover, rgba(0,0,0,0) 0%,rgba(0,0,0,0) 63%,rgba(0,0,0,0.65) 99%,rgba(0,0,0,0.65) 100%); /* Chrome10+,Safari5.1+ */
background: -o-radial-gradient(center, ellipse cover, rgba(0,0,0,0) 0%,rgba(0,0,0,0) 63%,rgba(0,0,0,0.65) 99%,rgba(0,0,0,0.65) 100%); /* Opera 12+ */
background: -ms-radial-gradient(center, ellipse cover, rgba(0,0,0,0) 0%,rgba(0,0,0,0) 63%,rgba(0,0,0,0.65) 99%,rgba(0,0,0,0.65) 100%); /* IE10+ */
background: radial-gradient(center, ellipse cover, rgba(0,0,0,0) 0%,rgba(0,0,0,0) 63%,rgba(0,0,0,0.65) 99%,rgba(0,0,0,0.65) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00000000', endColorstr='#a6000000',GradientType=1 ); /* IE6-8 fallback on horizontal gradient */
}
</style>
Работает в моем браузере, должен работать во всех браузерах. Это неопрятно, конечно, но позволяет вам установить это в HTML, тогда вы можете иметь тело, например, с цветом или изображением, которое вы хотите.
Посмотри на это в действии. http://jsfiddle.net/joshuamartin/taN2Z/4/
http://www.colorzilla.com/gradient-editor/