How to multiple background + gradient using CSS?

Just prepend the url of the image to each of your rules.

background: url(someurl), -moz-linear-gradient(top,  rgba(248,246,247,1) 0%, rgba(248,246,247,0) 100%); /* FF3.6+ */

Alternatively, if you don’t feel like adding url(etc) to each of your rules, you could just specify a single background-image rule:

background: -moz-linear-gradient(top,  rgba(248,246,247,1) 0%, rgba(248,246,247,0) 100%); /* FF3.6+ */

background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(248,246,247,1)), color-stop(100%,rgba(248,246,247,0))); /* Chrome,Safari4+ */

background-image:url("someurl");