/* ===== Responsive ===== */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    .header {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
        text-align: center;
    }
    
    .header-controls {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .subject-tabs {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .subject-tab {
        justify-content: center;
        padding: 0.625rem 1rem;
    }
    
    .subject-heading {
        font-size: 1.25rem;
    }
    
    .quiz-grid {
        grid-template-columns: 1fr;
    }
    
    .quiz-card.featured,
    .quiz-card.mega,
    .quiz-card.ultimate {
        grid-column: 1;
    }
    
    .quiz-header {
        flex-direction: column;
        gap: 1rem;
    }
    
    .question-container {
        padding: 1.5rem;
    }
    
    .question-text {
        font-size: 1.1rem;
    }
    
    .quiz-navigation {
        flex-wrap: wrap;
    }
    
    .nav-btn {
        flex: 1;
        min-width: 120px;
    }
    
    .results-card {
        padding: 2rem;
    }
    
    .teacher-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .teacher-actions {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .answer-key-item {
        flex-direction: column;
        gap: 0.75rem;
    }
    
    .answer-key-number {
        align-self: flex-start;
    }
    
    .study-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .study-header-left {
        flex-direction: column;
    }
    
    .study-grid {
        grid-template-columns: 1fr;
    }
    
    .study-card {
        padding: 1.25rem;
    }
    
    .study-card-icon {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .logo-text h1 {
        font-size: 1.25rem;
    }
    
    .card-icon {
        font-size: 2rem;
    }
    
    .quiz-card {
        padding: 1rem;
    }
    
    .option-btn {
        padding: 1rem;
    }
}