html,body{
    
    min-height: 100vh;
    margin: 0;
    padding: 0;
    position: relative;
    opacity: 1.0;
    background-color: #F4E9C1;
    font-family: "Helvetica";

    
}

a{
    text-decoration: none;
    color: black;
    
}
a:visited{
    text-decoration: none;
    color: black;
}

li{
      list-style: none;
}

header{
    margin-left: 1%;
    margin-top: 1%
    
}

h1{
    font-family: "Helvetica";
    font-size: 20px;
    color: #235181;
}

h3{
    color: #235181;

}

.cen{
    text-align: center;
    padding-top: 10vh;
    margin-left: auto;
    margin-right: auto;
    width: 50vw;

} 

.presentation{
    margin: 2%;
}

.platforme{
    margin-left: 1%;
}