body {
    background-color: #b3b3b3;
}

header, div, footer {
    font-family: Arial, Helvetica, sans-serif;
    background-color: #f5f5f5;
}

img {
    min-width: 200px;
    max-width: 300px;
    height: auto;
}

.card {
    width: 18rem;
}