@media (min-width: 800px;) {
    * {
        -webkit-box-sizing: border-box;
           -moz-box-sizing: border-box;
                box-sizing: border-box;
    }

body {width: auto;margin: 0;padding: 5%; padding-bottom: 5%; max-width:100%}
}
@media (max-width: 800px;) {
    * {
        -webkit-box-sizing: border-box;
           -moz-box-sizing: border-box;
                box-sizing: border-box;
    }

body {width: auto;margin: 0;padding: 0; padding-bottom: 5%; max-width:100%}
}
#contenu_centr {padding-bottom: 5%;}    
.verticentre {vertical-align: middle;}          
.milieu {text-align: center;margin-left: auto; margin-right: auto;}          
.justif {text-align: justify;}
.centre {text-align: center;}
.note {color:red}
.gras{font-weight : bold;}
.souligne {text-decoration : underline;}
.ligne {background-color : #DFF2FF;}

img,input {max-width:100%;height: auto;}