/* =========================================
   Base Styles (Existing)
   ========================================= */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 1rem;
    background: #f4f7f9; /* Slightly darker background */
    color: #333;
}

header {
    text-align: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background: #ffffff;
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
}

.card {
    background: white;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    padding: 20px;
    margin-bottom: 25px;
    border-left: 5px solid #007bff; /* Primary color hint */
}

.concept-title {
    color: #007bff;
    margin-top: 0;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

.category-tag {
    font-size: 0.9em;
    color: #6c757d;
    margin-bottom: 15px;
}

/* =========================================
   Quiz Section Styles (New)
   ========================================= */
.quiz-section {
    padding: 15px 0;
    border-bottom: 1px dashed #ddd;
}

.question-text {
    font-weight: bold;
    margin-bottom: 15px;
}

.options {
    margin-bottom: 20px;
}

.option-label {
    display: flex;
    align-items: center;
    padding: 8px 12px;
    margin-bottom: 5px;
    border: 1px solid #dee2e6;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.option-label:hover {
    background-color: #f8f9fa;
}

.option-text {
    margin-left: 10px;
    flex-grow: 1;
}

input[type="radio"] {
    /* Hide default radio button to use custom styling/indicators */
    opacity: 0;
    width: 0;
    height: 0;
}

/* Styles for correct/incorrect visual feedback */
.option-label.correct-choice {
    background-color: #d4edda; /* Light green */
    border-color: #155724;
}

.option-label.incorrect-choice {
    background-color: #f8d7da; /* Light red */
    border-color: #721c24;
}

/* Check Answer Button */
.check-answer-btn, .toggle-hint-btn {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
    font-weight: bold;
    margin-right: 10px;
}

.check-answer-btn:hover, .toggle-hint-btn:hover {
    background-color: #0056b3;
}

/* Feedback Area */
.feedback-area {
    margin-top: 15px;
    padding: 10px;
    border-radius: 5px;
    font-weight: bold;
}

.feedback-area.correct {
    background-color: #d4edda; /* Light Green */
    color: #155724; /* Dark Green */
}

.feedback-area.incorrect {
    background-color: #f8d7da; /* Light Red */
    color: #721c24; /* Dark Red */
}


/* =========================================
   Hint / Explanation Sections (New)
   ========================================= */
.hidden {
    display: none;
}

.hint-section {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px dashed #ddd;
}

.hint-content, .explanation-section {
    margin-top: 15px;
    padding: 15px;
    border-radius: 5px;
    background: #f0f7ff; /* Light blue/gray for content blocks */
    border: 1px solid #cce5ff;
}

/* Code Block Styling */
.code-block {
    background: #e9ecef;
    padding: 10px;
    border-radius: 5px;
    margin-bottom: 15px;
}

.code-block h3 {
    margin-top: 0;
    border-bottom: 1px solid #ddd;
    padding-bottom: 5px;
    font-size: 1.1em;
    color: #343a40;
}

.code-pair h4 {
    margin: 10px 0 5px 0;
    font-size: 0.9em;
    color: #007bff;
}

pre {
    background: #f8f9fa;
    padding: 10px;
    border-radius: 3px;
    overflow-x: auto;
    white-space: pre-wrap;
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 0.9em;
    border: 1px solid #ddd;
}

.visual-concept {
    background: #fff3cd; /* Light yellow for visual concept */
    border-left: 5px solid #ffc107; /* Yellow border */
    padding: 15px;
    margin-top: 15px;
}

.visual-concept h3 {
    margin-top: 0;
    font-size: 1.1em;
    color: #856404;
}

.analogy strong, .importance strong {
    color: #333;
}

.explanation-section {
    background: #e2f0d9; /* Light green/gray for explanation */
    border: 1px solid #c3e6cb;
}