body {
    font-family: sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

header {
    background-color: #333;
    color: #fff;
    padding: 20px;
    text-align: center;
    width: 100%;
}

main {
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    margin-top: 20px;
    text-align: center;
}

#greeting {
    font-size: 1.2em;
    margin-bottom: 15px;
}

button {
    background-color: #5cb85c;
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
}

button:hover {
    background-color: #4cae4c;
}

footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 10px;
    width: 100%;
    margin-top: auto;
}