codice:
body, html {
	width:100%;
	height:100%;
 /* IE10 Consumer Preview */ 
 background-image: -ms-linear-gradient(top, #FFFFFF 0%, #00A3EF 100%);

 /* Mozilla Firefox */ 
 background-image: -moz-linear-gradient(top, #FFFFFF 0%, #00A3EF 100%);

 /* Opera */ 
 background-image: -o-linear-gradient(top, #FFFFFF 0%, #00A3EF 100%);

 /* Webkit (Safari/Chrome 10) */ 
 background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0, #FFFFFF), color-stop(1, #00A3EF));

 /* Webkit (Chrome 11+) */ 
 background-image: -webkit-linear-gradient(top, #FFFFFF 0%, #00A3EF 100%);

 /* W3C Markup, IE10 Release Preview */ 
 background-image: linear-gradient(to bottom, #FFFFFF 0%, #00A3EF 100%);

 }
ATTENZIONE Quando posti del codice devi usare gli appositi tag [code]...&# 91;/code]