/* !! Mettre le display:inline-block d'abord aux parents !! */

body{
  margin:0;
  padding:0;
  font-family:sans-serif;
  box-sizing:border-box;
}
header {
    display:inline-block;
    background-color:#fd4900;
    height:120px;
    width:100%;
    position:sticky;
    top:0;
    color: white;
}
h1 {
    text-align:center;
    margin-top:5px;
}
.nav ul li {
    list-style:none;
    display:inline-block;
}
ul {
    display:flex;
    justify-content:space-around;
    margin-top:40px;
}
li {
    padding:4px 30px;
    background-color:#B7B7B7;
    border-radius:10px;
    font-weight:bold;
}
li:hover {
    background-color:#7A7A7A;
}
.liste {
    display:none;
    position:absolute;
}
.dropdwn:hover .liste {
    display:block;
}