body {
    background-color: darkgrey;
}
article {
    background-color: lightgray;
    border: 5px solid black;
}
header {
    text-align: center;
}
button {
    background-color: darkgray;
    border: 2px solid black;
    color: white;
    padding: 5px 10px;
    text-align: center;
    text-decoration: wavy;
    display: inline-block;
    font-size: 18px;
    border-radius: 8px;
}
button:hover {
    background-color: white;
    color: black;
}