:root {
    --bg-color: #f0f0f0;
    --container-bg: white;
    --text-color: #333;
    --choice-bg: #eee;
    --choice-hover-bg: #ddd;
    --choice-border: #ccc;
    --primary-btn: #007bff;
    --disabled-btn: #ccc;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --bg-color: #1a1a2e;
    --container-bg: #16213e;
    --text-color: #e0e0e0;
    --choice-bg: #0f3460;
    --choice-hover-bg: #1a4a7a;
    --choice-border: #2a5a8a;
    --primary-btn: #4a9eff;
    --disabled-btn: #444;
    --shadow-color: rgba(0, 0, 0, 0.4);
}

body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

#quiz-container {
    background-color: var(--container-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 0 10px var(--shadow-color);
    text-align: center;
    position: relative;
    transition: background-color 0.3s, box-shadow 0.3s;
}

#theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.25rem;
    line-height: 1;
}

#choices-container button {
    display: block;
    width: 100%;
    margin: 0.5rem 0;
    padding: 1rem;
    border: 1px solid var(--choice-border);
    border-radius: 5px;
    background-color: var(--choice-bg);
    color: var(--text-color);
    cursor: pointer;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

#choices-container button:hover {
    background-color: var(--choice-hover-bg);
}

#next-btn {
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    background-color: var(--primary-btn);
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
}

#next-btn:disabled {
    background-color: var(--disabled-btn);
}