:root {
    --bg: #f4f4f4;
    --text: #222;
    --card: white;
    --green: #4CAF50;
    --red: #E53935;
}

.dark {
    --bg: #1e1e1e;
    --text: #f5f5f5;
    --card: #2c2c2c;
    --green: #66ff66;
    --red: #ff6666;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 25px;
}

h1 {
    text-align: center;
}

.question {
    background: var(--card);
    padding: 15px;
    border-radius: 12px;
    margin-bottom: 15px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.correct {
    background: rgba(76,175,80,0.22);
    border-left: 5px solid var(--green);
}
.incorrect {
    background: rgba(229,57,53,0.22);
    border-left: 5px solid var(--red);
}

.correct-answer {
    margin-top: 8px;
    font-size: 14px;
    font-style: italic;
    color: var(--green);
}

button {
    padding: 12px 20px;
    font-size: 17px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
}

#submitBtn {
    background: #1976d2;
    color: white;
}
#resetBtn {
    background: #444;
    color: white;
}
#themeBtn {
    float: right;
    background: #ffaa00;
    color: black;
    margin-bottom: 20px;
}

.btn-row {
    display: flex;
    justify-content: center;
    gap: 20px;
}