:root {
    color: #263238;
    background: #f4f7f8;
    font-family: Arial, sans-serif;
}

body {
    margin: 0;
}

header,
main,
footer {
    box-sizing: border-box;
    max-width: 820px;
    margin: auto;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

nav a {
    margin-left: 16px;
    color: #00695c;
}

main {
    min-height: 280px;
    background: white;
    border-radius: 8px;
}

img {
    max-width: 100%;
    border-radius: 6px;
}

.button {
    display: inline-block;
    padding: 10px 14px;
    color: white;
    background: #00796b;
    border-radius: 4px;
    text-decoration: none;
}

footer {
    color: #607d8b;
    font-size: 14px;
}