test5.css

.nav {
    float: right ;
    list-style: none;
    margin-right: 10px;
}

.nav li{
    float: left ;
    display:inline;
    margin: 0 0 0 30px;
    width:100px;
   
    border: 1px solid white;
}
.nav li>a { font: 1em helvertica arial sans-serif ;
    line-height: 3em ;
    display : inline-block ;
    width:100px ;
    text-align:center;
    text-decoration : none ;
    font-weight:bold;
 }
   .nav a:hover { color :#fff ;
background-color :#db9834;}
 a{ color: white;}
#fondecran {
    
    position: fixed; 
    top: 0; 
    left: 0; 
    
    min-width: 100%;
    min-height: 100%;

}
.bg-image{
    height: 100vh;
    background-image: url("/home/marceline/Bureau/image/pic.png");
    filter: blur(8px);
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}
.contenu {
    z-index: 2 ;
    background-color: rgb(0,0,0);
    background-color: rgba(0,0,0, 0.4);
    color: white;
    font-weight: bold;
    border: 3px solid #f1f1f1;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 2;
    width: 80%;
    padding: 20px;
    text-align: center;
}