body {
            box-sizing: border-box;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Comic Neue', cursive;
            background: linear-gradient(135deg, #0f0f23 0%, #1a1a3e 50%, #2d1b69 100%);
            color: white;
            min-height: 100%;
            position: relative;
        }

        body::before {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: 
                radial-gradient(2px 2px at 20px 30px, #fff, transparent),
                radial-gradient(2px 2px at 40px 70px, rgba(255,255,255,0.8), transparent),
                radial-gradient(1px 1px at 90px 40px, #fff, transparent),
                radial-gradient(1px 1px at 130px 80px, rgba(255,255,255,0.6), transparent),
                radial-gradient(2px 2px at 160px 30px, #fff, transparent);
            background-repeat: repeat;
            background-size: 200px 100px;
            z-index: -1;
            opacity: 0.3;
        }

        /* Navbar Styles */
        .navbar {
            background: rgba(15, 15, 35, 0.95);
            backdrop-filter: blur(10px);
            padding: 1rem 2rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            border-bottom: 2px solid rgba(255, 255, 255, 0.1);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 1.5rem;
            font-weight: 700;
            color: #ff6b9d;
        }

        .rocket-icon {
            font-size: 2rem;
            animation: float 3s ease-in-out infinite;
        }

        @keyframes float {
            0%, 100% { transform: translateY(0px); }
            50% { transform: translateY(-10px); }
        }

        .nav-center {
            display: flex;
            align-items: center;
            gap: 1rem;
            flex: 1;
            justify-content: center;
        }

        .search-box {
            position: relative;
            display: flex;
            align-items: center;
        }

        .search-input {
            background: #ff6b9d;
            border: none;
            padding: 0.75rem 1rem 0.75rem 3rem;
            border-radius: 25px;
            color: white;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            width: 300px;
            outline: none;
        }

        .search-input::placeholder {
            color: rgba(255, 255, 255, 0.8);
        }

        .search-icon {
            position: absolute;
            left: 1rem;
            color: white;
            font-size: 1.2rem;
        }

        .nav-icons {
            display: flex;
            align-items: center;
            gap: 1.5rem;
        }

        .settings-menu-container {
            display: flex;
            align-items: center;
            margin-left: auto;
        }

        .settings-btn {
            margin-left: 1rem;
        }

        .auth-container {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

        .auth-buttons {
            display: flex;
            align-items: center;
            gap: 0.75rem;
        }

        .auth-btn {
            background: #4ecdc4;
            border: none;
            color: white;
            padding: 0.6rem 1.2rem;
            border-radius: 20px;
            font-family: 'Comic Neue', cursive;
            font-size: 0.9rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
            text-transform: uppercase;
            white-space: nowrap;
        }

        .auth-btn:hover {
            background: #45b7d1;
            transform: scale(1.05);
        }

        .auth-btn.signup {
            background: #ff6b9d;
        }

        .auth-btn.signup:hover {
            background: #e55a87;
        }

        .user-info {
            display: flex;
            align-items: center;
            gap: 1rem;
            background: rgba(78, 205, 196, 0.2);
            padding: 0.5rem 1rem;
            border-radius: 20px;
            border: 2px solid #4ecdc4;
        }

        .user-welcome {
            color: #4ecdc4;
            font-weight: 700;
            font-size: 0.9rem;
        }

        .nav-icon {
            background: none;
            border: none;
            color: white;
            font-size: 1.5rem;
            cursor: pointer;
            padding: 0.5rem;
            border-radius: 50%;
            transition: all 0.3s ease;
        }

        .nav-icon:hover {
            background: rgba(255, 255, 255, 0.1);
            transform: scale(1.1);
        }

        .stars-display {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            background: rgba(255, 107, 157, 0.2);
            padding: 0.5rem 1rem;
            border-radius: 20px;
            border: 2px solid #ff6b9d;
        }

        .star-icon {
            color: #ffd700;
            font-size: 1.2rem;
        }

        .stars-count {
            font-weight: 700;
            color: #ffd700;
        }

        /* Main Content */
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 2rem;
        }

        .hero-section {
            text-align: center;
            margin-bottom: 3rem;
        }

        .hero-title {
            font-size: 3rem;
            font-weight: 700;
            margin-bottom: 1rem;
            background: linear-gradient(45deg, #ff6b9d, #4ecdc4, #45b7d1);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .hero-description {
            font-size: 1.2rem;
            color: rgba(255, 255, 255, 0.9);
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.6;
        }

        /* Daily Challenges */
        .daily-challenges {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 2rem;
            margin-bottom: 3rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .challenges-title {
            font-size: 1.8rem;
            font-weight: 700;
            text-align: center;
            margin-bottom: 1.5rem;
            color: #4ecdc4;
        }

        .challenges-grid {
            display: flex;
            justify-content: center;
            gap: 1rem;
            flex-wrap: wrap;
        }

        .challenge-circle {
            width: 60px;
            height: 60px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 3px solid;
        }

        .challenge-completed {
            background: #4caf50;
            border-color: #4caf50;
            color: white;
        }

        .challenge-pending {
            background: rgba(128, 128, 128, 0.3);
            border-color: #808080;
            color: #808080;
        }

        .challenge-circle:hover {
            transform: scale(1.1);
        }

        /* Class Selection */
        .class-selection-section {
            margin-bottom: 3rem;
        }

        .class-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
        }

        .class-card {
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 2rem;
            text-align: center;
            border: 2px solid rgba(255, 255, 255, 0.1);
            transition: all 0.3s ease;
        }

        .class-card:hover {
            transform: translateY(-10px);
            border-color: rgba(255, 255, 255, 0.3);
        }

        .class-card.selected {
            border-color: #4ecdc4;
            background: rgba(78, 205, 196, 0.1);
        }

        .class-icon {
            font-size: 4rem;
            margin-bottom: 1rem;
        }

        .class-title {
            font-size: 1.8rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            color: #4ecdc4;
        }

        .class-description {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
            margin-bottom: 1.5rem;
        }

        .class-btn {
            padding: 0.75rem 2rem;
            border: none;
            border-radius: 25px;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
            text-transform: uppercase;
        }

        .btn-class1 {
            background: #e74c3c;
            color: white;
        }

        .btn-class1:hover {
            background: #c0392b;
            transform: scale(1.05);
        }

        .btn-class2 {
            background: #f39c12;
            color: white;
        }

        .btn-class2:hover {
            background: #e67e22;
            transform: scale(1.05);
        }

        .btn-class3 {
            background: #9b59b6;
            color: white;
        }

        .btn-class3:hover {
            background: #8e44ad;
            transform: scale(1.05);
        }

        /* Categories */
        .categories-section {
            margin-bottom: 3rem;
        }

        .categories-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
        }

        .search-results {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 15px;
            padding: 1rem;
            margin-bottom: 2rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
            display: none;
        }

        .search-results h3 {
            color: #4ecdc4;
            margin-bottom: 1rem;
            font-size: 1.2rem;
        }

        .search-item {
            background: rgba(255, 255, 255, 0.05);
            padding: 0.75rem;
            border-radius: 10px;
            margin-bottom: 0.5rem;
            cursor: pointer;
            transition: all 0.3s ease;
            border-left: 3px solid #ff6b9d;
        }

        .search-item:hover {
            background: rgba(255, 255, 255, 0.1);
            transform: translateX(5px);
        }

        .category-card {
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 2rem;
            text-align: center;
            border: 2px solid rgba(255, 255, 255, 0.1);
            transition: all 0.3s ease;
        }

        .category-card:hover {
            transform: translateY(-10px);
            border-color: rgba(255, 255, 255, 0.3);
        }

        .category-icon {
            font-size: 4rem;
            margin-bottom: 1rem;
        }

        .category-title {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
        }

        .category-btn {
            padding: 0.75rem 2rem;
            border: none;
            border-radius: 25px;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
            text-transform: uppercase;
        }

        .btn-math {
            background: #e74c3c;
            color: white;
        }

        .btn-math:hover {
            background: #c0392b;
            transform: scale(1.05);
        }

        .btn-english {
            background: #27ae60;
            color: white;
        }

        .btn-english:hover {
            background: #229954;
            transform: scale(1.05);
        }

        .btn-indonesian {
            background: #3498db;
            color: white;
        }

        .btn-indonesian:hover {
            background: #2980b9;
            transform: scale(1.05);
        }

        /* Selected Class Info */
        .selected-class-info {
            background: rgba(78, 205, 196, 0.1);
            border: 2px solid #4ecdc4;
            border-radius: 15px;
            padding: 1rem;
            margin-bottom: 2rem;
            text-align: center;
            display: none;
        }

        .selected-class-info h3 {
            color: #4ecdc4;
            margin-bottom: 0.5rem;
        }

        .change-class-btn {
            background: rgba(255, 255, 255, 0.2);
            border: 2px solid rgba(255, 255, 255, 0.3);
            color: white;
            padding: 0.5rem 1rem;
            border-radius: 15px;
            font-family: 'Comic Neue', cursive;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-top: 0.5rem;
        }

        .change-class-btn:hover {
            background: rgba(255, 255, 255, 0.3);
        }

        /* Popular & Recommend Sections */
        .popular-section, .recommend-section {
            margin-bottom: 3rem;
        }

        .section-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 1.5rem;
        }

        .section-title {
            font-size: 2rem;
            font-weight: 700;
            color: #4ecdc4;
            font-family: 'Comic Neue', cursive;
        }

        .scroll-btn {
            background: linear-gradient(135deg, #ff6b9d, #c44569);
            border: none;
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(255, 107, 157, 0.4);
            font-family: 'Comic Neue', cursive;
        }

        .scroll-btn:hover {
            transform: scale(1.1);
            box-shadow: 0 6px 20px rgba(255, 107, 157, 0.6);
            background: linear-gradient(135deg, #c44569, #ff6b9d);
        }

        .scroll-btn:active {
            transform: scale(0.95);
        }

        .cards-container {
            display: flex;
            gap: 1.5rem;
            overflow-x: auto;
            scroll-behavior: smooth;
            padding: 1rem 0.5rem;
            scrollbar-width: none;
            -ms-overflow-style: none;
        }

        .cards-container::-webkit-scrollbar {
            display: none;
        }

        .quiz-card {
            position: relative;
            min-width: 280px;
            height: 200px;
            background: rgba(15, 15, 35, 0.8);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            border: 2px solid rgba(255, 255, 255, 0.1);
            cursor: pointer;
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
            overflow: hidden;
            flex-shrink: 0;
        }

        .quiz-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: linear-gradient(135deg, 
                rgba(255, 107, 157, 0.1) 0%, 
                rgba(78, 205, 196, 0.1) 50%, 
                rgba(69, 183, 209, 0.1) 100%);
            opacity: 0;
            transition: opacity 0.4s ease;
            z-index: 1;
        }

        .quiz-card:hover::before {
            opacity: 1;
        }

        .card-glow {
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, 
                rgba(255, 107, 157, 0.3) 0%, 
                rgba(78, 205, 196, 0.2) 30%, 
                transparent 70%);
            opacity: 0;
            transition: opacity 0.4s ease, transform 0.4s ease;
            pointer-events: none;
            z-index: 2;
        }

        .quiz-card:hover .card-glow {
            opacity: 1;
            transform: scale(1.1);
        }

        .quiz-card:hover {
            transform: translateY(-10px);
            border-color: rgba(255, 107, 157, 0.5);
            box-shadow: 
                0 10px 40px rgba(255, 107, 157, 0.3),
                0 0 30px rgba(78, 205, 196, 0.2),
                inset 0 0 20px rgba(255, 255, 255, 0.05);
        }

        .card-content {
            position: relative;
            z-index: 3;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            height: 100%;
            padding: 1.5rem;
            text-align: center;
        }

        .card-icon {
            font-size: 3.5rem;
            margin-bottom: 1rem;
            transition: transform 0.3s ease;
            filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.3));
        }

        .quiz-card:hover .card-icon {
            transform: scale(1.15) rotate(5deg);
        }

        .card-title {
            font-size: 1.3rem;
            font-weight: 700;
            color: white;
            margin-bottom: 0.5rem;
            font-family: 'Comic Neue', cursive;
            text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
            transition: color 0.3s ease;
        }

        .quiz-card:hover .card-title {
            color: #ff6b9d;
        }

        .card-subject {
            font-size: 0.95rem;
            color: rgba(255, 255, 255, 0.7);
            font-family: 'Comic Neue', cursive;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 1px;
            transition: color 0.3s ease;
        }

        .quiz-card:hover .card-subject {
            color: #4ecdc4;
        }

        /* Animation for cards on load */
        @keyframes cardFloat {
            0%, 100% { transform: translateY(0px); }
            50% { transform: translateY(-5px); }
        }

        .quiz-card:nth-child(even) {
            animation: cardFloat 3s ease-in-out infinite;
        }

        .quiz-card:nth-child(odd) {
            animation: cardFloat 3.5s ease-in-out infinite;
        }

        /* Quiz Page */
        .quiz-container {
            display: none;
            max-width: 800px;
            margin: 0 auto;
        }

        .quiz-header {
            text-align: center;
            margin-bottom: 2rem;
        }

        .quiz-title {
            font-size: 2.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
        }

        .quiz-progress {
            background: rgba(255, 255, 255, 0.2);
            height: 10px;
            border-radius: 5px;
            overflow: hidden;
            margin-bottom: 1rem;
        }

        .quiz-progress-bar {
            background: #4ecdc4;
            height: 100%;
            transition: width 0.3s ease;
        }

        .question-card {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 2rem;
            margin-bottom: 2rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .question-text {
            font-size: 1.3rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
            text-align: center;
        }

        .answers-grid {
            display: grid;
            gap: 1rem;
        }

        .answer-btn {
            background: rgba(255, 255, 255, 0.1);
            border: 2px solid rgba(255, 255, 255, 0.3);
            color: white;
            padding: 1rem;
            border-radius: 15px;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            text-align: left;
        }

        .answer-btn:hover {
            background: rgba(255, 255, 255, 0.2);
            border-color: #4ecdc4;
        }

        .answer-btn.selected {
            background: #4ecdc4;
            border-color: #4ecdc4;
        }

        .quiz-controls {
            display: flex;
            justify-content: center;
            gap: 1rem;
            margin-top: 2rem;
        }

        .control-btn {
            padding: 0.75rem 2rem;
            border: none;
            border-radius: 25px;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .btn-primary {
            background: #4ecdc4;
            color: white;
        }

        .btn-primary:hover {
            background: #45b7d1;
            transform: scale(1.05);
        }

        .btn-secondary {
            background: rgba(255, 255, 255, 0.2);
            color: white;
            border: 2px solid rgba(255, 255, 255, 0.3);
        }

        .btn-secondary:hover {
            background: rgba(255, 255, 255, 0.3);
        }

        /* Results */
        .results-container {
            display: none;
            text-align: center;
        }

        .results-title {
            font-size: 2.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: #4ecdc4;
        }

        .results-score {
            font-size: 3rem;
            font-weight: 700;
            color: #ffd700;
            margin-bottom: 1rem;
        }

        .results-stars {
            font-size: 1.5rem;
            margin-bottom: 2rem;
        }

        /* Leaderboard */
        .leaderboard-container {
            display: none;
        }

        .leaderboard-title {
            font-size: 2.5rem;
            font-weight: 700;
            text-align: center;
            margin-bottom: 2rem;
            color: #ffd700;
        }

        .leaderboard-list {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 2rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .leaderboard-item {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 1rem;
            margin-bottom: 0.5rem;
            background: rgba(255, 255, 255, 0.05);
            border-radius: 10px;
            border-left: 4px solid #4ecdc4;
        }

        .leaderboard-rank {
            font-size: 1.5rem;
            font-weight: 700;
            color: #ffd700;
            width: 50px;
        }

        .leaderboard-name {
            flex: 1;
            font-size: 1.2rem;
            font-weight: 600;
        }

        .leaderboard-stars {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 1.1rem;
            font-weight: 700;
            color: #ffd700;
        }

        /* Login Modal */
        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            z-index: 1000;
            justify-content: center;
            align-items: center;
        }

        .modal-content {
            background: rgba(15, 15, 35, 0.95);
            backdrop-filter: blur(20px);
            border-radius: 20px;
            padding: 2rem;
            max-width: 400px;
            width: 90%;
            border: 2px solid rgba(255, 255, 255, 0.2);
        }

        .modal-title {
            font-size: 1.8rem;
            font-weight: 700;
            text-align: center;
            margin-bottom: 1.5rem;
            color: #4ecdc4;
        }

        .form-group {
            margin-bottom: 1rem;
        }

        .form-label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
            color: rgba(255, 255, 255, 0.9);
        }

        .form-input {
            width: 100%;
            padding: 0.75rem;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.1);
            color: white;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            outline: none;
        }

        .form-input:focus {
            border-color: #4ecdc4;
        }

        .form-input::placeholder {
            color: rgba(255, 255, 255, 0.6);
        }

        .modal-buttons {
            display: flex;
            gap: 1rem;
            margin-top: 1.5rem;
        }

        .loading {
            opacity: 0.7;
            pointer-events: none;
        }

        .loading::after {
            content: '⏳';
            margin-left: 0.5rem;
        }

        /* Desktop Navigation Buttons */
        .desktop-nav-buttons {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

        /* Comments Section */
        .comments-container {
            display: none;
        }

        .comments-title {
            font-size: 2.5rem;
            font-weight: 700;
            text-align: center;
            margin-bottom: 2rem;
            color: #4ecdc4;
        }

        .comment-form {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 15px;
            padding: 1.5rem;
            margin-bottom: 2rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .comment-textarea {
            width: 100%;
            min-height: 100px;
            padding: 1rem;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.1);
            color: white;
            font-family: 'Comic Neue', cursive;
            font-size: 1rem;
            resize: vertical;
            outline: none;
        }

        .comment-textarea:focus {
            border-color: #4ecdc4;
        }

        .comment-textarea::placeholder {
            color: rgba(255, 255, 255, 0.6);
        }

        .comments-list {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 15px;
            padding: 1.5rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .comment-item {
            background: rgba(255, 255, 255, 0.05);
            border-radius: 10px;
            padding: 1rem;
            margin-bottom: 1rem;
            border-left: 3px solid #ff6b9d;
        }

        .comment-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 0.5rem;
        }

        .comment-author {
            font-weight: 700;
            color: #4ecdc4;
        }

        .comment-time {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
        }

        .comment-text {
            margin-bottom: 0.5rem;
            line-height: 1.5;
        }

        .comment-actions {
            display: flex;
            gap: 1rem;
        }

        .reply-btn {
            background: none;
            border: none;
            color: #4ecdc4;
            cursor: pointer;
            font-size: 0.9rem;
            padding: 0.25rem 0.5rem;
            border-radius: 5px;
            transition: all 0.3s ease;
        }

        .reply-btn:hover {
            background: rgba(78, 205, 196, 0.2);
        }

        .reply-form {
            margin-top: 1rem;
            padding-left: 1rem;
            border-left: 2px solid rgba(255, 255, 255, 0.3);
            display: none;
        }

        .reply-textarea {
            width: 100%;
            min-height: 60px;
            padding: 0.75rem;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 8px;
            background: rgba(255, 255, 255, 0.1);
            color: white;
            font-family: 'Comic Neue', cursive;
            font-size: 0.9rem;
            resize: vertical;
            outline: none;
        }

        .reply-textarea:focus {
            border-color: #4ecdc4;
        }

        .replies-container {
            margin-top: 1rem;
            padding-left: 1rem;
            border-left: 2px solid rgba(255, 255, 255, 0.2);
        }

        .reply-item {
            background: rgba(255, 255, 255, 0.03);
            border-radius: 8px;
            padding: 0.75rem;
            margin-bottom: 0.5rem;
            border-left: 2px solid #45b7d1;
        }

        .reply-indicator {
            background: rgba(78, 205, 196, 0.2);
            padding: 0.2rem 0.5rem;
            border-radius: 10px;
            font-weight: 600;
        }

        /* Answer Review Styles */
        .answer-review-item {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 15px;
            padding: 1.5rem;
            margin-bottom: 1rem;
            border: 2px solid rgba(255, 255, 255, 0.2);
        }

        .answer-review-item.correct {
            border-color: #4caf50;
            background: rgba(76, 175, 80, 0.1);
        }

        .answer-review-item.incorrect {
            border-color: #f44336;
            background: rgba(244, 67, 54, 0.1);
        }

        .review-question-number {
            display: inline-block;
            background: #4ecdc4;
            color: white;
            padding: 0.25rem 0.75rem;
            border-radius: 15px;
            font-size: 0.9rem;
            font-weight: 700;
            margin-bottom: 1rem;
        }

        .review-question-text {
            font-size: 1.1rem;
            font-weight: 600;
            margin-bottom: 1rem;
            line-height: 1.4;
        }

        .review-answers {
            display: grid;
            gap: 0.5rem;
            margin-bottom: 1rem;
        }

        .review-answer-option {
            padding: 0.75rem;
            border-radius: 10px;
            border: 2px solid rgba(255, 255, 255, 0.2);
            background: rgba(255, 255, 255, 0.05);
            font-size: 0.95rem;
        }

        .review-answer-option.user-answer {
            border-color: #ff6b9d;
            background: rgba(255, 107, 157, 0.1);
        }

        .review-answer-option.correct-answer {
            border-color: #4caf50;
            background: rgba(76, 175, 80, 0.1);
        }

        .review-answer-option.user-answer.correct-answer {
            border-color: #4caf50;
            background: rgba(76, 175, 80, 0.2);
        }

        .review-status {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-weight: 700;
            font-size: 1rem;
        }

        .review-status.correct {
            color: #4caf50;
        }

        .review-status.incorrect {
            color: #f44336;
        }

        .review-legend {
            background: rgba(255, 255, 255, 0.1);
            border-radius: 10px;
            padding: 1rem;
            margin-bottom: 1.5rem;
            font-size: 0.9rem;
        }

        .legend-item {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            margin-bottom: 0.5rem;
        }

        .legend-color {
            width: 20px;
            height: 20px;
            border-radius: 5px;
            border: 2px solid;
        }

        .legend-correct {
            background: rgba(76, 175, 80, 0.1);
            border-color: #4caf50;
        }

        .legend-user {
            background: rgba(255, 107, 157, 0.1);
            border-color: #ff6b9d;
        }

        .review-summary {
            background: rgba(78, 205, 196, 0.1);
            border: 2px solid #4ecdc4;
            border-radius: 15px;
            padding: 1.5rem;
            margin-bottom: 1.5rem;
            text-align: center;
        }

        .summary-stats {
            display: flex;
            justify-content: center;
            gap: 2rem;
            margin-top: 1rem;
        }

        .stat-item {
            text-align: center;
        }

        .stat-number {
            font-size: 1.5rem;
            font-weight: 700;
            display: block;
        }

        .stat-label {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.8);
        }

        /* Responsive */
        @media (max-width: 768px) {
            .desktop-nav-buttons {
                display: none;
            }

            .navbar {
                padding: 0.75rem 1rem;
                flex-wrap: nowrap;
                gap: 0.5rem;
                position: relative;
                align-items: center;
            }

            .logo {
                font-size: 1rem;
                order: 1;
                flex-shrink: 0;
            }

            .rocket-icon {
                font-size: 1.3rem;
            }

            .nav-center {
                order: 2;
                flex: 1;
                justify-content: flex-start;
                margin: 0;
                margin-left: 0.5rem;
            }

            .search-input {
                width: 100%;
                max-width: 140px;
                padding: 0.5rem 0.6rem 0.5rem 2rem;
                font-size: 0.8rem;
            }

            .search-icon {
                left: 0.6rem;
                font-size: 0.9rem;
            }

            .nav-icons {
                order: 3;
                flex-shrink: 0;
                justify-content: flex-end;
            }

            .settings-menu-container {
                order: 4;
                margin-left: 0.5rem;
                flex-shrink: 0;
            }

            .settings-btn {
                margin-left: 0;
            }

            .auth-buttons {
                gap: 0.25rem;
            }

            .auth-btn {
                font-size: 0.7rem;
                padding: 0.4rem 0.6rem;
                border-radius: 12px;
                white-space: nowrap;
            }

            .user-info {
                flex-direction: row;
                gap: 0.25rem;
                padding: 0.3rem 0.5rem;
                border-radius: 12px;
                font-size: 0.7rem;
            }

            .user-welcome {
                font-size: 0.7rem;
                white-space: nowrap;
            }

            .stars-display {
                padding: 0.2rem 0.4rem;
                border-radius: 10px;
                font-size: 0.7rem;
            }

            .star-icon {
                font-size: 0.9rem;
            }

            .nav-icons {
                gap: 0.5rem;
            }

            .nav-icon {
                font-size: 1.3rem;
                padding: 0.4rem;
            }

            .hero-title {
                font-size: 2rem;
                line-height: 1.2;
            }

            .hero-description {
                font-size: 1rem;
                line-height: 1.5;
            }

            .categories-grid, .class-grid {
                grid-template-columns: 1fr;
                gap: 1.5rem;
            }

            .challenges-grid {
                gap: 0.5rem;
                justify-content: center;
            }

            .challenge-circle {
                width: 45px;
                height: 45px;
                font-size: 1.1rem;
            }

            .challenges-title {
                font-size: 1.5rem;
            }

            .section-title {
                font-size: 1.5rem;
            }

            .scroll-btn {
                width: 40px;
                height: 40px;
            }

            .scroll-btn span {
                font-size: 1.2rem;
            }

            .quiz-card {
                min-width: 220px;
                height: 180px;
            }

            .card-icon {
                font-size: 2.5rem;
            }

            .card-title {
                font-size: 1.1rem;
            }

            .card-subject {
                font-size: 0.85rem;
            }

            .cards-container {
                gap: 1rem;
            }

            .popular-section, .recommend-section {
                margin-bottom: 2rem;
            }

            .class-card, .category-card {
                padding: 1.5rem;
            }

            .class-icon, .category-icon {
                font-size: 3rem;
            }

            .class-title, .category-title {
                font-size: 1.3rem;
            }

            .class-btn, .category-btn {
                padding: 0.6rem 1.5rem;
                font-size: 0.9rem;
            }

            .quiz-title {
                font-size: 2rem;
            }

            .question-text {
                font-size: 1.1rem;
            }

            .answer-btn {
                padding: 0.8rem;
                font-size: 0.9rem;
            }

            .control-btn {
                padding: 0.6rem 1.5rem;
                font-size: 0.9rem;
            }

            .results-title {
                font-size: 2rem;
            }

            .results-score {
                font-size: 2.5rem;
            }

            .leaderboard-title {
                font-size: 2rem;
            }

            .comments-title {
                font-size: 2rem;
            }

            .comment-textarea, .reply-textarea {
                font-size: 0.9rem;
            }

            .comment-item {
                padding: 0.8rem;
            }

            .comment-author {
                font-size: 0.9rem;
            }

            .comment-time {
                font-size: 0.8rem;
            }

            .comment-text {
                font-size: 0.9rem;
            }

            .reply-btn {
                font-size: 0.8rem;
            }

            .container {
                padding: 1rem;
            }

            .daily-challenges {
                padding: 1.5rem;
                margin-bottom: 2rem;
            }

            .selected-class-info {
                padding: 0.8rem;
                margin-bottom: 1.5rem;
            }

            .search-results {
                margin-bottom: 1.5rem;
                padding: 0.8rem;
            }

            .search-item {
                padding: 0.6rem;
                font-size: 0.9rem;
            }

            .modal-content {
                padding: 1.5rem;
                max-width: 350px;
            }

            .modal-title {
                font-size: 1.5rem;
            }

            .form-input {
                padding: 0.6rem;
                font-size: 0.9rem;
            }

            .form-label {
                font-size: 0.9rem;
            }

            .summary-stats {
                flex-direction: column;
                gap: 1rem;
            }
            
            .review-answers {
                gap: 0.25rem;
            }
            
            .review-answer-option {
                padding: 0.5rem;
                font-size: 0.9rem;
            }
            
            .comment-item[style*="margin-left"] {
                margin-left: 10px !important;
                max-width: calc(100% - 20px);
            }
            
            .comment-header {
                flex-wrap: wrap;
                gap: 0.5rem;
            }
            
            .reply-indicator, .thread-starter {
                font-size: 0.7rem !important;
                padding: 0.15rem 0.4rem !important;
            }
            
            .comment-actions {
                flex-wrap: wrap;
                gap: 0.5rem;
            }
            
            .reply-form {
                margin-top: 0.75rem;
            }
            
            .reply-textarea {
                min-height: 80px;
                font-size: 0.9rem;
            }
            
            .comment-actions > div {
                flex-direction: column;
                align-items: flex-start;
                gap: 0.5rem;
            }
            
            .comment-actions button {
                font-size: 0.8rem;
                padding: 0.4rem 0.8rem;
            }
        }

        @media (max-width: 480px) {
            .navbar {
                padding: 0.5rem 0.75rem;
            }

            .logo {
                font-size: 1rem;
            }

            .rocket-icon {
                font-size: 1.3rem;
            }

            .search-input {
                max-width: 250px;
                padding: 0.5rem 0.7rem 0.5rem 2.2rem;
                font-size: 0.85rem;
            }

            .auth-btn {
                font-size: 0.75rem;
                padding: 0.4rem 0.6rem;
            }

            .user-welcome {
                font-size: 0.7rem;
            }

            .stars-display {
                font-size: 0.75rem;
            }

            .hero-title {
                font-size: 1.7rem;
            }

            .hero-description {
                font-size: 0.9rem;
            }

            .challenges-title {
                font-size: 1.3rem;
            }

            .challenge-circle {
                width: 40px;
                height: 40px;
                font-size: 1rem;
            }

            .section-title {
                font-size: 1.3rem;
            }

            .quiz-card {
                min-width: 200px;
                height: 160px;
            }

            .card-icon {
                font-size: 2rem;
                margin-bottom: 0.75rem;
            }

            .card-title {
                font-size: 1rem;
            }

            .card-subject {
                font-size: 0.8rem;
            }

            .class-card, .category-card {
                padding: 1.2rem;
            }

            .class-icon, .category-icon {
                font-size: 2.5rem;
            }

            .class-title, .category-title {
                font-size: 1.2rem;
            }

            .container {
                padding: 0.75rem;
            }

            .daily-challenges {
                padding: 1.2rem;
            }
        }

        .hidden {
            display: none !important;
        }

        /* Footer Styles */
        .site-footer-bg {
            background-color: #0d0d1a;
            width: 100%;
            margin: 0;
            padding: 60px 0;
            box-sizing: border-box;
            margin-top: 4rem;
        }

        .site-footer {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 40px;
            color: #ffffff;
            font-family: 'Comic Neue', cursive;
            box-sizing: border-box;
        }

        .footer-container {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 60px;
            text-align: left;
        }

        .footer-column {
            flex: 1;
            min-width: 200px;
        }

        .footer-column h3 {
            font-weight: 700;
            margin-bottom: 20px;
            font-size: 18px;
            color: #ff6b9d;
        }

        .footer-column ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .footer-column ul li {
            margin-bottom: 12px;
            font-weight: 400;
            cursor: pointer;
            transition: color 0.2s ease;
            color: rgba(255, 255, 255, 0.8);
        }

        .footer-column ul li:hover {
            color: #4ecdc4;
        }

        .footer-bottom {
            margin-top: 50px;
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }

        .footer-bottom p {
            color: #cccccc;
            font-size: 14px;
            margin: 0;
        }

        @media (max-width: 768px) {
            .site-footer-bg {
                padding: 40px 0;
            }

            .footer-container {
                gap: 30px;
            }

            .footer-column {
                min-width: 150px;
            }

            .footer-column h3 {
                font-size: 16px;
            }

            .footer-column ul li {
                font-size: 14px;
                margin-bottom: 10px;
            }

            .footer-bottom {
                margin-top: 30px;
            }
        }