/* Exercise System Styles */

.exercise-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 24px;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.exercise-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid #f0f0f0;
}

.exercise-type {
    font-size: 14px;
    font-weight: 600;
    color: #667eea;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.exercise-difficulty {
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}

.difficulty-basic {
    background: #d4edda;
    color: #155724;
}

.difficulty-intermediate {
    background: #fff3cd;
    color: #856404;
}

.difficulty-advanced {
    background: #f8d7da;
    color: #721c24;
}

.difficulty-expert {
    background: #d1ecf1;
    color: #0c5460;
}

.exercise-question {
    margin-bottom: 24px;
}

.exercise-question h3 {
    font-size: 18px;
    line-height: 1.6;
    color: #333;
    margin: 0;
}

.exercise-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 24px;
}

.option-item {
    display: flex;
    align-items: center;
    padding: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.option-item:hover {
    border-color: #667eea;
    background: #f8f9ff;
}

.option-item input[type="radio"] {
    margin-right: 12px;
    cursor: pointer;
}

.option-item label {
    flex: 1;
    cursor: pointer;
    font-size: 16px;
    color: #333;
}

.exercise-input {
    margin-bottom: 24px;
}

.exercise-input label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #333;
}

.exercise-input input[type="text"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.2s;
}

.exercise-input input[type="text"]:focus {
    outline: none;
    border-color: #667eea;
}

.blank-input {
    display: inline-block;
    min-width: 120px;
    padding: 4px 8px;
    border: none;
    border-bottom: 2px solid #667eea;
    font-size: 16px;
    text-align: center;
    background: #f8f9ff;
}

.blank-input:focus {
    outline: none;
    background: #fff;
}

.exercise-actions {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
}

.btn-submit,
.btn-hint {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-submit {
    background: #667eea;
    color: white;
    flex: 1;
}

.btn-submit:hover {
    background: #5568d3;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(102, 126, 234, 0.3);
}

.btn-hint {
    background: #f0f0f0;
    color: #666;
}

.btn-hint:hover {
    background: #e0e0e0;
}

.exercise-feedback {
    display: none;
    margin-top: 24px;
    padding: 20px;
    border-radius: 8px;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feedback-correct {
    display: flex;
    gap: 16px;
    background: #d4edda;
    border: 2px solid #c3e6cb;
}

.feedback-incorrect {
    display: flex;
    gap: 16px;
    background: #f8d7da;
    border: 2px solid #f5c6cb;
}

.feedback-hint {
    display: flex;
    gap: 16px;
    background: #fff3cd;
    border: 2px solid #ffeaa7;
}

.feedback-icon {
    font-size: 32px;
    line-height: 1;
}

.feedback-content {
    flex: 1;
}

.feedback-content h4 {
    margin: 0 0 8px 0;
    font-size: 18px;
    color: #333;
}

.feedback-content p {
    margin: 4px 0;
    font-size: 14px;
    line-height: 1.6;
    color: #666;
}

.correct-answer {
    font-weight: 600;
    color: #155724;
}

.explanation {
    font-style: italic;
    color: #666;
}