html {
    max-width: 800px;
    margin: auto;
}

body {
    font-family: Arial, Helvetica, sans-serif;
}
body, button {
    font-size: 18px;
    padding: 0;
    margin: 0;
}

.header {
    background-color: #f2f2f2;
    padding: 4px 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.header a {
    color: #700;
    text-decoration: none;
}

.main h2 {
    text-align: center;
}

.footer {
    margin-top: 30px;
}