* {
    margin: 0;
    padding: 0;
}

.bandeau {
    background-color: greenyellow;
    border: 1px solid grey;
    text-align: center;
    padding:0px;
}

.menu-principal {
    display: inline-block;
    position: relative;
}

.menu-principal div{
    background-color: green;
    color: white;
    cursor: pointer;
    padding: 20px;
    font-size: 20px;
}

.menu-principal div:hover {
        background-color: limegreen;
      }
      
.menu-principal:hover .sous-menu {
        display: block;
      }

.sous-menu {
    display: none;
    position: absolute;
    top: 63px;
    left: 0px;
    padding: 0px;
}


.sous-menu li {
    display: block;
    background-color: limegreen;
    color: white;
    text-decoration: none;
    list-style: none;
    text-align: center;
    cursor: pointer;
    padding: 20px;
    width: 136px;
}

.sous-menu li:hover {
        background-color: lime;
      }