body {
    font-family: Arial, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f5f5f5;
}
.quiz-container {
    background-color: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
.question {
    font-size: 18px;
    margin-bottom: 20px;
    font-weight: bold;
}
.options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.option {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}
.option:hover {
    background-color: #f0f0f0;
}
.option.selected {
    background-color: #d4edda;
    border-color: #c3e6cb;
}
.option.correct {
    background-color: #d4edda;
    border-color: #c3e6cb;
}
.option.incorrect {
    background-color: #f8d7da;
    border-color: #f5c6cb;
}
.feedback {
    margin-top: 20px;
    padding: 10px;
    border-radius: 5px;
    display: none;
}
.correct-feedback {
    background-color: #d4edda;
    color: #155724;
}
.incorrect-feedback {
    background-color: #f8d7da;
    color: #721c24;
}
.next-btn, .mode-btn {
    padding: 10px 20px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    margin-top: 20px;
}
.next-btn:hover, .mode-btn:hover {
    background-color: #0056b3;
}
.score-display {
    font-size: 18px;
    margin-top: 20px;
    font-weight: bold;
}
.mode-selection {
    text-align: center;
    margin-bottom: 30px;
}
.progress-bar {
    width: 100%;
    background-color: #e9ecef;
    border-radius: 5px;
    margin-bottom: 20px;
}
.progress {
    height: 20px;
    background-color: #28a745;
    border-radius: 5px;
    width: 0%;
    transition: width 0.3s;
}
.hidden {
    display: none;
}
.question img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 10px auto;
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 5px;
}