*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    padding-bottom: 1500px ;
}
nav{
    background-color: #333;
}
nav ul{
    list-style: none;
    display: flex;
    gap: 1rem;
    padding: 1rem;
}
nav ul a{
 color: #fff;
 padding: 15px;
 text-decoration: none;
}
nav ul a:hover{
    background-color: #222;
}

nav ul li:hover > ul{
    display: block;
}

nav ul ul{
    display: none;
    position: absolute;
    width: 100px;
    top: 50px;
    background-color: #444;
    padding: 0;
    font-size: .8rem;
}

nav ul ul li{
    position: relative;
}

nav ul ul li a{
  padding: .5rem;
  display: block;
}


nav ul ul ul{
    left: 100px;
    top:0 ;
    background-color: #555;
}
#back-to-top{
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #333;
    padding: 0.5rem 1rem;
    color: #fff;
    text-decoration: none;
    transition: .4s;
}
#back-to-top:hover{
    background-color: #555;
}

header img{
    
    background-size: cover;
    width: 100vw;
    height: 80vh;
}