body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f2f2f2;
}

h1 {
    text-align: center;
    margin-top: 20px;
}

.theme-loader {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 20px;
}

#themeSelect {
    margin-right: 10px;
    padding: 10px;
    font-size: 16px;
}

button {
    padding: 10px 20px;
    font-size: 16px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button:hover {
    background-color: #45a049;
}

iframe {
    width: 100%;
    height: 600px;
    border: 1px solid #ddd;
    margin-top: 20px;
}