body {
    margin:0;
    font-family:"Arial;", sans-serif;
}
header nav {
    height :420px;
    background:#6e9bac;
    opacity:=0.8;
    height:50px;
    box-shadow:0 0 10px #000;
}
header nav ul {
    margin:0;
    padding:0;
    list-style:none;
    float:right;
    display:flex;
}
header nav ul li a {
    float:left;
    line-height:50px; 
    padding:0px 18px;
    font-weight: bold;
    text-decoration:none;
    color:rgb(32, 30, 30);
    opacity:.4;
    transition:opacity .25s;
}
header nav ul li a:hover {
    opacity:1;
}
main article {
    margin-left: 20px
}

footer {
    height:50px;
    background:#6e9bac;
}

footer p {
    float:right;
    color:rgb(32, 30, 30);
    opacity:.4;
    margin-right:  10px;
}