body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

:root {
    --bg-color: #ffffff;
    --text-color: #000000;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #333333;
        --text-color: #ffffff;
    }
}

header {
    display: flex;
    align-items: center;
    padding: 10px 20px;
    background-color: var(--bg-color);
    border-bottom: 1px solid #ccc;
}

.logo {
    height: 50px;
    margin-right: 20px;
}

nav {
    display: flex;
    gap: 10px;
}

button {
    padding: 10px 20px;
    border: none;
    cursor: pointer;
    background-color: #555;
    color: #fff;
    border-radius: 5px;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #777;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
}

iframe {
    width: 100%;
    height: 100%;
    border: none;
}

#error-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #f8d7da;
    color: #721c24;
    padding: 20px;
    border: 1px solid #f5c6cb;
    border-radius: 5px;
    display: none;
}

#error-popup.hidden {
    display: none;
}