Background dégradé
.gradient {
background: -webkit-radial-gradient(center center, rgb(RR, GG, BB) 0%, rgb(RR, GG, BB) 100%);
background: -moz-radial-gradient(center center, rgb(RR, GG, BB) 0%, rgb(RR, GG, BB) 100%);
background: -ms-radial-gradient(center center, rgb(RR, GG, BB) 0%, rgb(RR, GG, BB) 100%);
background: -o-radial-gradient(center center, rgb(RR, GG, BB) 0%, rgb(RR, GG, BB) 100%);
background: radial-gradient(center center, rgb(RR, GG, BB) 0%, rgb(RR, GG, BB) 100%);
}