* {
    box-sizing: border-box;
}

body {
    font-family: sans-serif;
    font-size: 20px;
    margin: 0 auto;
    text-align: center;
}

a,
a:visited {
    color: #007bff;
}

a:hover {
    color: #0056b3;
}

nav ul {
    list-style-type: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin: 0 5px;
}

main {
    width: 80%;
    margin: 0 auto;
}

.codigo {
    font-weight: bold;
}