#site_center {text-align:center;}
#main {margin:0 auto; width:760px; text-align:left;}

.col_1, .col_2, .col_3 {float:left;}

/*======= ACCUEIL =======*/
#accueil .col_1{width:280px;}
#accueil .col_2{width:200px;}
#accueil .col_3{width:280px;}