static/styles.css

#container {
    width: 800px;
    height: 600px;
    border: 1px solid #ccc;
    margin: 20px auto;
}

#controls {
    text-align: center;
    margin-bottom: 10px;
}

button {
    padding: 10px 20px;
    margin: 5px;
    cursor: pointer;
}