*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    background-color: #000;
    color: #FFF;
}
header{
    background-color: deepskyblue;
    position: fixed;
    top: 0;
    width: 100vw;
    left: 0;
    height: 10vh;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1em 2em;
}
nav > ul{
    list-style-type: none;
    display: flex;
    align-items: center;
    gap: 1em;
    margin-right: 1em;
    position: relative;
}
nav > ul li a{
    color: #FFF;
}
nav > ul ul{
    position: absolute;
    background-color: cornflowerblue;
    display: block;
    width: 10rem;
    padding: 2em;

}
li.submenu{
    visibility: hidden;
    position: relative;
}
li.submenu p{
    visibility: visible;
}
li.submenu:hover{
    visibility: visible;
}
main{
    max-width: 50rem;
    margin: 10vh auto;
}
footer{
    position: fixed;
    width: 100vw;
    bottom: 0;
    background-color: deepskyblue;
    left: 0;
    height: 10vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1em;
}