* {
    margin: 0;
    box-sizing: border-box;
}

div {
    width: 800px;
    margin: auto;
    background-color: royalblue;
    text-align: center;
}

header {
    background-color: yellowgreen;
}

header h1 {
    color: darkgreen;
}

nav {
    background-color: blueviolet;
}

nav ul {
    padding-left: 0;
}

nav ul li {
    display: inline;
}

main {
    background-color: darkred;
}

main p {
    color: yellow;
    border: 5px rebeccapurple dashed;
}

footer {
    background-color: gray;
}