/* ========================================
   ENHANCED RESPONSIVE DESIGN
   Tối ưu cho mọi thiết bị và kích thước màn hình
   ======================================== */

/* ========================================
   BREAKPOINTS
   ======================================== */
/* 
   - Mobile Small: < 480px
   - Mobile: 480px - 767px
   - Tablet: 768px - 1023px
   - Desktop Small: 1024px - 1279px
   - Desktop: 1280px - 1919px
   - Desktop Large: >= 1920px
*/

/* ========================================
   BASE RESPONSIVE UTILITIES
   ======================================== */

/* Prevent horizontal scroll */
html, body {
    overflow-x: hidden;
    max-width: 100vw;
}

/* Touch-friendly tap targets */
@media (hover: none) and (pointer: coarse) {
    button,
    a,
    .nav-item,
    .option,
    .option-modern,
    .question-grid-item {
        min-height: 44px;
        min-width: 44px;
    }
}

/* ========================================
   DESKTOP LARGE (>= 1920px)
   ======================================== */
@media (min-width: 1920px) {
    .container {
        max-width: 1600px;
    }
    
    .modern-quiz-layout {
        grid-template-columns: 350px 1fr 380px;
        gap: 30px;
    }
    
    .question-grid {
        grid-template-columns: repeat(8, 1fr);
    }
    
    .stats-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* ========================================
   DESKTOP (1280px - 1919px)
   ======================================== */
@media (min-width: 1280px) and (max-width: 1919px) {
    .modern-quiz-layout {
        grid-template-columns: 320px 1fr 340px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* ========================================
   DESKTOP SMALL (1024px - 1279px)
   ======================================== */
@media (min-width: 1024px) and (max-width: 1279px) {
    .sidebar {
        width: 240px;
    }
    
    .main-wrapper {
        margin-left: 240px;
    }
    
    .modern-quiz-layout {
        grid-template-columns: 280px 1fr 300px;
        gap: 16px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .question-grid {
        grid-template-columns: repeat(6, 1fr);
    }
    
    .quiz-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
}

/* ========================================
   TABLET (768px - 1023px)
   ======================================== */
@media (min-width: 768px) and (max-width: 1023px) {
    /* Sidebar - Mobile Menu */
    .sidebar {
        transform: translateX(-100%);
        box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .main-wrapper {
        margin-left: 0;
    }
    
    /* Add hamburger menu button */
    .mobile-menu-toggle {
        display: flex !important;
        align-items: center;
        justify-content: center;
        width: 40px;
        height: 40px;
        background: var(--bg-secondary);
        border: none;
        border-radius: 8px;
        cursor: pointer;
        color: var(--text-primary);
        font-size: 20px;
    }
    
    /* Header adjustments */
    .top-header {
        padding: 0 16px;
        gap: 16px;
    }
    
    .header-center {
        max-width: 400px;
    }
    
    .btn-create-quiz {
        padding: 10px 14px;
    }
    
    .btn-create-quiz span {
        display: none;
    }
    
    /* Modern Quiz Layout - Stack vertically */
    .modern-quiz-layout {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .quiz-sidebar-left {
        order: 2;
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }
    
    .quiz-actions-card {
        grid-column: 1 / -1;
        display: flex;
        flex-direction: row;
        gap: 12px;
    }
    
    .quiz-main-content {
        order: 1;
    }
    
    .quiz-sidebar-right {
        order: 3;
        position: static;
        max-height: none;
    }
    
    .question-grid {
        grid-template-columns: repeat(10, 1fr);
        gap: 8px;
    }
    
    /* Stats Grid */
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    /* Quiz Grid */
    .quiz-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    /* Features Grid */
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    /* Form adjustments */
    .form-card {
        padding: 24px;
    }
    
    /* Modal */
    .modal-content {
        width: 95%;
        max-width: 600px;
    }
}

/* ========================================
   MOBILE (480px - 767px)
   ======================================== */
@media (min-width: 480px) and (max-width: 767px) {
    /* Sidebar */
    .sidebar {
        transform: translateX(-100%);
        width: 280px;
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .main-wrapper {
        margin-left: 0;
    }
    
    /* Header */
    .top-header {
        height: 60px;
        padding: 0 12px;
        gap: 12px;
    }
    
    .header-left {
        display: none;
    }
    
    .header-center {
        flex: 1;
    }
    
    .search-bar {
        padding: 8px 12px;
    }
    
    .btn-create-quiz span,
    .theme-toggle-btn {
        display: none;
    }
    
    /* Main Content */
    .main-content-area {
        padding: 16px 12px;
    }
    
    .page-title {
        font-size: 20px;
    }
    
    /* Modern Quiz Layout */
    .modern-quiz-layout {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .quiz-sidebar-left {
        order: 2;
        display: flex;
        flex-direction: column;
        gap: 12px;
    }
    
    .quiz-info-card,
    .quiz-timer-card,
    .quiz-settings-card,
    .quiz-progress-card {
        padding: 16px;
    }
    
    .quiz-actions-card {
        display: flex;
        flex-direction: column;
        gap: 10px;
    }
    
    .quiz-main-content {
        order: 1;
    }
    
    .quiz-sidebar-right {
        order: 3;
        position: static;
        max-height: none;
        padding: 16px;
    }
    
    /* Question Card */
    .question-card-modern {
        padding: 20px 16px;
        min-height: auto;
    }
    
    .question-text-modern {
        font-size: 16px;
        padding: 16px;
    }
    
    .option-modern {
        padding: 14px 16px;
    }
    
    .option-modern .option-text {
        font-size: 15px;
    }
    
    /* Question Grid */
    .question-grid {
        grid-template-columns: repeat(8, 1fr);
        gap: 6px;
    }
    
    .question-grid-item {
        font-size: 13px;
    }
    
    /* Navigation */
    .quiz-navigation {
        flex-direction: column;
        gap: 10px;
    }
    
    .btn-nav {
        width: 100%;
        justify-content: center;
    }
    
    /* Stats */
    .stats-section {
        padding: 16px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .stat-card {
        padding: 16px;
    }
    
    /* Quiz Grid */
    .quiz-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    /* Features */
    .features-section {
        padding: 16px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    /* Form */
    .form-card {
        padding: 20px 16px;
    }
    
    .form-actions {
        flex-direction: column;
        gap: 10px;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
        justify-content: center;
    }
    
    /* Modal */
    .modal-content {
        width: 95%;
        margin: 10px;
    }
    
    .modal-header,
    .modal-body,
    .modal-footer {
        padding: 16px;
    }
    
    .modal-footer {
        flex-direction: column;
    }
    
    /* Results */
    .results-header {
        padding: 30px 20px;
    }
    
    .score-display {
        font-size: 56px;
    }
    
    .results-stats {
        grid-template-columns: 1fr;
        gap: 12px;
    }
}

/* ========================================
   MOBILE SMALL (< 480px)
   ======================================== */
@media (max-width: 479px) {
    /* Sidebar */
    .sidebar {
        transform: translateX(-100%);
        width: 100%;
        max-width: 280px;
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .main-wrapper {
        margin-left: 0;
    }
    
    /* Header */
    .top-header {
        height: 56px;
        padding: 0 12px;
        gap: 8px;
    }
    
    .header-left {
        display: none;
    }
    
    .header-center {
        flex: 1;
    }
    
    .search-bar {
        padding: 8px 12px;
        font-size: 14px;
    }
    
    .btn-create-quiz {
        padding: 8px;
        width: 36px;
        height: 36px;
    }
    
    .btn-create-quiz span {
        display: none;
    }
    
    .theme-toggle-btn {
        width: 36px;
        height: 36px;
        padding: 8px;
    }
    
    .user-avatar-small {
        width: 32px;
        height: 32px;
        font-size: 12px;
    }
    
    /* Main Content */
    .main-content-area {
        padding: 12px 8px;
    }
    
    .page-title {
        font-size: 18px;
        gap: 8px;
    }
    
    .page-title i {
        font-size: 20px;
    }
    
    /* Modern Quiz Layout */
    .modern-quiz-layout {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .quiz-sidebar-left {
        order: 2;
        display: flex;
        flex-direction: column;
        gap: 10px;
    }
    
    .quiz-info-card,
    .quiz-timer-card,
    .quiz-settings-card,
    .quiz-progress-card,
    .quiz-actions-card {
        padding: 14px;
    }
    
    .quiz-title-sidebar {
        font-size: 16px;
    }
    
    .timer-display {
        font-size: 28px;
    }
    
    .quiz-actions-card {
        display: flex;
        flex-direction: column;
        gap: 8px;
    }
    
    .btn-back-quiz,
    .btn-submit-quiz {
        padding: 10px 16px;
        font-size: 13px;
    }
    
    .quiz-main-content {
        order: 1;
    }
    
    .quiz-sidebar-right {
        order: 3;
        position: static;
        max-height: none;
        padding: 14px;
    }
    
    /* Question Card */
    .question-card,
    .question-card-modern {
        padding: 16px 12px;
        min-height: auto;
    }
    
    .question-header {
        gap: 10px;
    }
    
    .question-number {
        min-width: 36px;
        height: 36px;
        font-size: 14px;
    }
    
    .question-text,
    .question-text-modern {
        font-size: 15px;
        line-height: 1.6;
        padding: 14px;
    }
    
    .question-label {
        font-size: 12px;
        padding: 6px 14px;
    }
    
    /* Options */
    .option,
    .option-modern {
        padding: 12px 14px;
        gap: 10px;
    }
    
    .option input[type="radio"],
    .option-modern input[type="radio"] {
        width: 20px;
        height: 20px;
    }
    
    .option-label,
    .option-modern .option-letter {
        min-width: 24px;
        font-size: 15px;
    }
    
    .option-text,
    .option-modern .option-text {
        font-size: 14px;
        line-height: 1.5;
    }
    
    /* Question Grid */
    .question-grid {
        grid-template-columns: repeat(6, 1fr);
        gap: 6px;
    }
    
    .question-grid-item {
        font-size: 12px;
        border-width: 1.5px;
    }
    
    .grid-title {
        font-size: 14px;
    }
    
    /* Navigation */
    .quiz-navigation {
        flex-direction: column;
        gap: 8px;
    }
    
    .btn-nav {
        width: 100%;
        justify-content: center;
        padding: 12px 20px;
        font-size: 14px;
    }
    
    /* Stats */
    .stats-section,
    .recent-section,
    .features-section {
        padding: 14px;
        margin-bottom: 12px;
    }
    
    .section-title {
        font-size: 16px;
        margin-bottom: 14px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    
    .stat-card {
        padding: 14px;
        gap: 12px;
    }
    
    .stat-icon {
        width: 40px;
        height: 40px;
        font-size: 18px;
    }
    
    .stat-value {
        font-size: 20px;
    }
    
    .stat-label {
        font-size: 12px;
    }
    
    /* Quiz Grid */
    .quiz-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    
    /* Features */
    .features-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .feature-card {
        padding: 16px;
    }
    
    .feature-icon {
        font-size: 32px;
        margin-bottom: 12px;
    }
    
    .feature-card h3 {
        font-size: 15px;
    }
    
    .feature-card p {
        font-size: 13px;
    }
    
    /* Form */
    .form-card {
        padding: 16px 12px;
    }
    
    .form-group {
        margin-bottom: 16px;
    }
    
    .form-group label {
        font-size: 13px;
        margin-bottom: 6px;
    }
    
    .form-input,
    .form-textarea,
    .form-select {
        padding: 10px 12px;
        font-size: 14px;
    }
    
    .form-textarea {
        min-height: 100px;
    }
    
    .form-textarea.large {
        min-height: 150px;
    }
    
    .btn-paste-inline {
        position: static;
        margin-bottom: 8px;
        width: 100%;
        justify-content: center;
    }
    
    .form-actions {
        flex-direction: column;
        gap: 8px;
        margin-top: 20px;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
        justify-content: center;
        padding: 12px 20px;
        font-size: 14px;
    }
    
    /* Modal */
    .modal-content {
        width: 100%;
        max-width: 100%;
        height: 100vh;
        max-height: 100vh;
        border-radius: 0;
    }
    
    .modal-header {
        padding: 14px;
    }
    
    .modal-header h3 {
        font-size: 16px;
    }
    
    .modal-body {
        padding: 14px;
        max-height: calc(100vh - 140px);
    }
    
    .modal-footer {
        padding: 14px;
        flex-direction: column;
        gap: 8px;
    }
    
    /* Results */
    .results-header {
        padding: 24px 16px;
    }
    
    .performance-badge {
        font-size: 60px;
    }
    
    .quiz-title-result {
        font-size: 16px;
    }
    
    .score-display {
        font-size: 48px;
    }
    
    .score-text {
        font-size: 16px;
    }
    
    .results-stats {
        grid-template-columns: 1fr;
        gap: 10px;
        margin-bottom: 20px;
    }
    
    .stat-number {
        font-size: 28px;
    }
    
    .stat-label {
        font-size: 13px;
    }
    
    .result-question {
        padding: 16px;
        margin-bottom: 12px;
    }
    
    .result-question-text {
        font-size: 15px;
    }
    
    .result-answers {
        font-size: 14px;
    }
    
    /* Action Buttons */
    .action-buttons-container {
        padding: 16px;
        gap: 10px;
        margin: 20px 0;
    }
    
    /* AI Quiz */
    .ai-info-banner {
        padding: 14px;
        font-size: 13px;
    }
    
    .ai-info-banner i {
        font-size: 20px;
    }
    
    .ai-preview-section {
        padding: 16px;
    }
    
    .preview-question {
        padding: 16px;
    }
    
    /* Scroll to Top */
    .scroll-to-top {
        width: 48px;
        height: 48px;
        bottom: 16px;
        right: 16px;
        font-size: 20px;
    }
    
    /* Toast */
    .toast {
        bottom: 16px;
        right: 16px;
        left: 16px;
        min-width: auto;
        padding: 14px 16px;
        font-size: 14px;
    }
}

/* ========================================
   LANDSCAPE ORIENTATION (Mobile)
   ======================================== */
@media (max-height: 500px) and (orientation: landscape) {
    .top-header {
        height: 50px;
    }
    
    .quiz-sidebar-left {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }
    
    .quiz-actions-card {
        grid-column: 1 / -1;
        flex-direction: row;
    }
    
    .question-card-modern {
        min-height: auto;
    }
    
    .modal-content {
        max-height: 95vh;
    }
    
    .results-header {
        padding: 20px;
    }
    
    .performance-badge {
        font-size: 48px;
        margin-bottom: 10px;
    }
    
    .score-display {
        font-size: 40px;
    }
}

/* ========================================
   PRINT STYLES
   ======================================== */
@media print {
    .sidebar,
    .top-header,
    .quiz-sidebar-left,
    .quiz-sidebar-right,
    .quiz-navigation,
    .quiz-actions-card,
    .btn-primary,
    .btn-secondary,
    .scroll-to-top,
    .modal {
        display: none !important;
    }
    
    .main-wrapper {
        margin-left: 0;
    }
    
    .modern-quiz-layout {
        grid-template-columns: 1fr;
    }
    
    .question-card,
    .question-card-modern {
        page-break-inside: avoid;
        border: 1px solid #000;
        margin-bottom: 20px;
    }
    
    body {
        background: white;
        color: black;
    }
}

/* ========================================
   ACCESSIBILITY IMPROVEMENTS
   ======================================== */

/* Focus visible for keyboard navigation */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .option,
    .option-modern,
    .question-card,
    .question-card-modern {
        border-width: 2px;
    }
    
    .btn-primary,
    .btn-secondary {
        border: 2px solid currentColor;
    }
}

/* ========================================
   UTILITY CLASSES FOR RESPONSIVE
   ======================================== */

/* Hide on mobile */
@media (max-width: 767px) {
    .hide-mobile {
        display: none !important;
    }
}

/* Hide on tablet */
@media (min-width: 768px) and (max-width: 1023px) {
    .hide-tablet {
        display: none !important;
    }
}

/* Hide on desktop */
@media (min-width: 1024px) {
    .hide-desktop {
        display: none !important;
    }
}

/* Show only on mobile */
.show-mobile {
    display: none !important;
}

@media (max-width: 767px) {
    .show-mobile {
        display: block !important;
    }
}

/* Responsive text sizes */
.text-responsive {
    font-size: clamp(14px, 2vw, 18px);
}

.heading-responsive {
    font-size: clamp(20px, 4vw, 32px);
}

/* Container max-width responsive */
.container-responsive {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 clamp(12px, 3vw, 24px);
}

/* ========================================
   SAFE AREA INSETS (for notched devices)
   ======================================== */
@supports (padding: max(0px)) {
    .top-header {
        padding-left: max(12px, env(safe-area-inset-left));
        padding-right: max(12px, env(safe-area-inset-right));
    }
    
    .sidebar {
        padding-left: max(0px, env(safe-area-inset-left));
    }
    
    .main-content-area {
        padding-left: max(12px, env(safe-area-inset-left));
        padding-right: max(12px, env(safe-area-inset-right));
        padding-bottom: max(12px, env(safe-area-inset-bottom));
    }
}