/* Challenge Subject Dropdown */
        .challenge-select {
            width: 100%;
            padding: 12px 15px;
            border: 2px solid rgba(56, 239, 125, 0.3);
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.05);
            color: #fff;
            font-size: 1rem;
            font-family: 'Cairo', sans-serif;
            outline: none;
            cursor: pointer;
            margin-bottom: 10px;
            transition: all 0.3s ease;
        }

        .challenge-select:focus {
            border-color: #38ef7d;
            box-shadow: 0 0 15px rgba(56, 239, 125, 0.3);
        }

        .challenge-select option {
            background: #1a1a2e;
            color: #fff;
            padding: 10px;
        }

        /* Subject Cards Section */
        .subjects-section {
            padding: 60px 0;
            background: linear-gradient(180deg, rgba(26, 26, 46, 0.5) 0%, rgba(22, 33, 62, 0.5) 100%);
        }

        .subjects-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 25px;
            margin-top: 30px;
        }

        .subject-card {
            background: rgba(255, 255, 255, 0.05);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.1);
            border-radius: 20px;
            padding: 30px;
            text-align: center;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }

        .subject-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, #38ef7d, #11998e);
            opacity: 0;
            transition: opacity 0.3s ease;
        }

        .subject-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
            border-color: rgba(56, 239, 125, 0.3);
        }

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

        .subject-icon {
            width: 80px;
            height: 80px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            font-size: 2rem;
            color: white;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
        }

        .subject-card h3 {
            color: white;
            font-size: 1.5rem;
            margin-bottom: 5px;
        }

        .subject-card>p {
            color: rgba(255, 255, 255, 0.6);
            font-size: 0.9rem;
            margin-bottom: 25px;
        }

        .subject-actions {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .subject-btn {
            padding: 12px 20px;
            border: none;
            border-radius: 10px;
            font-size: 0.95rem;
            font-family: 'Cairo', sans-serif;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }

        .subject-btn.challenge-btn {
            background: linear-gradient(135deg, #38ef7d, #11998e);
            color: white;
        }

        .subject-btn.bank-btn {
            background: rgba(255, 255, 255, 0.1);
            color: white;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .subject-btn.leaderboard-btn {
            background: rgba(255, 193, 7, 0.15);
            color: #ffc107;
            border: 1px solid rgba(255, 193, 7, 0.3);
        }

        .subject-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        }

        .subject-btn.challenge-btn:hover {
            box-shadow: 0 5px 20px rgba(56, 239, 125, 0.4);
        }

        @media (max-width: 768px) {
            .subjects-grid {
                grid-template-columns: 1fr;
            }

            .subject-card {
                padding: 25px;
            }
        }

        /* Challenge Modal */
        .challenge-modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.9);
            z-index: 2000;
            overflow-y: auto;
            padding: 20px;
        }

        .challenge-modal.active {
            display: flex;
            align-items: flex-start;
            justify-content: center;
        }

        .modal-content {
            background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
            border-radius: 20px;
            max-width: 800px;
            width: 100%;
            margin: 20px auto;
            border: 1px solid rgba(255, 255, 255, 0.1);
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
        }

        .modal-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 20px 25px;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .modal-header h2 {
            color: white;
            font-size: 1.5rem;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .modal-close {
            background: none;
            border: none;
            color: rgba(255, 255, 255, 0.7);
            font-size: 2rem;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .modal-close:hover {
            color: #f5576c;
            transform: rotate(90deg);
        }

        .modal-body {
            padding: 25px;
        }

        .modal-tabs {
            display: flex;
            gap: 10px;
            margin-bottom: 25px;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
            padding-bottom: 15px;
        }

        .modal-tab {
            padding: 10px 20px;
            background: rgba(255, 255, 255, 0.05);
            border: none;
            border-radius: 10px;
            color: rgba(255, 255, 255, 0.7);
            cursor: pointer;
            transition: all 0.3s ease;
            font-family: 'Cairo', sans-serif;
        }

        .modal-tab.active {
            background: linear-gradient(135deg, #38ef7d, #11998e);
            color: white;
        }

        .modal-tab:hover:not(.active) {
            background: rgba(255, 255, 255, 0.1);
        }

        .tab-content {
            display: none;
        }

        .tab-content.active {
            display: block;
        }

        /* Modal Leaderboard */
        .modal-leaderboard {
            max-height: 400px;
            overflow-y: auto;
        }

        .modal-leaderboard-item {
            display: flex;
            align-items: center;
            padding: 12px 15px;
            background: rgba(255, 255, 255, 0.05);
            border-radius: 10px;
            margin-bottom: 8px;
            transition: all 0.3s ease;
        }

        .modal-leaderboard-item:hover {
            background: rgba(255, 255, 255, 0.1);
        }

        .modal-leaderboard-item .rank {
            width: 35px;
            height: 35px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            font-weight: bold;
            margin-left: 15px;
        }

        .modal-leaderboard-item .rank.gold {
            background: linear-gradient(135deg, #ffd700, #ffb347);
            color: #000;
        }

        .modal-leaderboard-item .rank.silver {
            background: linear-gradient(135deg, #c0c0c0, #a0a0a0);
            color: #000;
        }

        .modal-leaderboard-item .rank.bronze {
            background: linear-gradient(135deg, #cd7f32, #b87333);
            color: #000;
        }

        .modal-leaderboard-item .rank.normal {
            background: rgba(255, 255, 255, 0.1);
            color: white;
        }

        .modal-leaderboard-item .info {
            flex: 1;
        }

        .modal-leaderboard-item .name {
            color: white;
            font-weight: 600;
        }

        .modal-leaderboard-item .time {
            color: rgba(255, 255, 255, 0.5);
            font-size: 0.85rem;
        }

        .modal-leaderboard-item .score {
            background: linear-gradient(135deg, #38ef7d, #11998e);
            padding: 5px 15px;
            border-radius: 20px;
            color: white;
            font-weight: bold;
        }

        /* Modal Challenge Interface */
        .modal-challenge-intro {
            text-align: center;
            padding: 30px 0;
        }

        .modal-challenge-intro h3 {
            color: white;
            font-size: 1.8rem;
            margin-bottom: 15px;
        }

        .modal-challenge-intro p {
            color: rgba(255, 255, 255, 0.7);
            margin-bottom: 25px;
        }

        .modal-name-input {
            max-width: 400px;
            margin: 0 auto;
        }

        .modal-name-input input {
            width: 100%;
            padding: 15px 20px;
            background: rgba(255, 255, 255, 0.08);
            border: 2px solid rgba(56, 239, 125, 0.3);
            border-radius: 12px;
            color: white;
            font-size: 1rem;
            margin-bottom: 15px;
            text-align: center;
        }

        .modal-name-input input:focus {
            outline: none;
            border-color: #38ef7d;
        }

        .modal-start-btn {
            width: 100%;
            padding: 15px;
            background: linear-gradient(135deg, #38ef7d, #11998e);
            border: none;
            border-radius: 12px;
            color: white;
            font-size: 1.2rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .modal-start-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 30px rgba(56, 239, 125, 0.4);
        }

        /* Space Theme - مطابق للمنصة */
        body.space-theme {
            background: #05051a;
        }

        body.space-theme .navbar {
            background: rgba(10, 10, 42, 0.95);
            border-bottom: 2px solid rgba(0, 255, 255, 0.2);
            backdrop-filter: blur(10px);
        }

        body.space-theme .hero {
            background: linear-gradient(135deg, #0a0a2a 0%, #1a1a4a 50%, #4a1a6a 100%);
        }

        body.space-theme .section {
            background: linear-gradient(180deg, #0a0a2a 0%, #05051a 100%);
        }

        body.space-theme .subjects-section {
            background: transparent;
        }

        body.space-theme .subject-card {
            background: linear-gradient(145deg, rgba(26, 26, 74, 0.8) 0%, rgba(74, 26, 106, 0.6) 100%);
            border: 2px solid rgba(0, 255, 255, 0.15);
        }

        body.space-theme .subject-card:hover {
            border-color: rgba(0, 255, 255, 0.6);
            box-shadow: 0 0 30px rgba(0, 255, 255, 0.3);
        }

        body.space-theme h1,
        body.space-theme h2,
        body.space-theme h3 {
            color: #00ffff;
            text-shadow: 0 0 15px rgba(0, 255, 255, 0.4);
        }

        body.space-theme .section-title {
            color: #00ffff;
        }

        body.space-theme .btn-primary {
            background: linear-gradient(45deg, #00ffff, #1a1a4a);
            color: #0a0a2a;
            box-shadow: 0 0 20px rgba(0, 255, 255, 0.4);
        }

        body.space-theme .btn-secondary {
            background: transparent;
            border: 2px solid #00ffff;
            color: #00ffff;
        }

        body.space-theme .modal-content,
        body.space-theme .profile-content {
            background: rgba(10, 10, 42, 0.95);
            border: 2px solid rgba(0, 255, 255, 0.3);
            box-shadow: 0 0 50px rgba(0, 255, 255, 0.2);
        }

        /* النجوم المتحركة - 3 طبقات */
        body.space-theme::before,
        body.space-theme::after {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: -1;
        }

        body.space-theme::before {
            background: transparent url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMjAwIiBoZWlnaHQ9IjIwMCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48Y2lyY2xlIGN4PSIxMDAiIGN5PSIxMDAiIHI9IjAuNSIgZmlsbD0iI2ZmZiIvPjwvc3ZnPg==') repeat;
            animation: moveStars 200s linear infinite;
            opacity: 0.4;
        }

        body.space-theme::after {
            background: transparent url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMzAwIiBoZWlnaHQ9IjMwMCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48Y2lyY2xlIGN4PSIxNTAiIGN5PSIxNTAiIHI9IjEiIGZpbGw9IiNmZmYiLz48L3N2Zz4=') repeat;
            animation: moveStars 150s linear infinite reverse;
            opacity: 0.25;
        }

        @keyframes moveStars {
            from {
                transform: translateY(0) translateX(0);
            }

            to {
                transform: translateY(-1000px) translateX(-500px);
            }
        }

        /* الكواكب العائمة */
        .space-planet {
            position: fixed;
            border-radius: 50%;
            z-index: -1;
            filter: blur(1px);
            display: none;
        }

        body.space-theme .space-planet {
            display: block;
        }

        .planet-1 {
            width: 250px;
            height: 250px;
            background: radial-gradient(circle at 30% 30%, #4a1a6a, #1a1a4a);
            top: 10%;
            right: 5%;
            animation: floatPlanet 25s infinite ease-in-out;
            box-shadow: 0 0 50px rgba(74, 26, 106, 0.5);
        }

        .planet-2 {
            width: 180px;
            height: 180px;
            background: radial-gradient(circle at 40% 40%, #1a4a4a, #0a2a2a);
            bottom: 15%;
            left: 8%;
            animation: floatPlanet 20s infinite ease-in-out reverse;
            box-shadow: 0 0 40px rgba(26, 74, 74, 0.5);
        }

        .planet-3 {
            width: 120px;
            height: 120px;
            background: radial-gradient(circle at 50% 50%, #6a4a1a, #4a2a0a);
            top: 55%;
            right: 15%;
            animation: floatPlanet 15s infinite ease-in-out;
            box-shadow: 0 0 30px rgba(106, 74, 26, 0.5);
        }

        @keyframes floatPlanet {

            0%,
            100% {
                transform: translateY(0) rotate(0deg);
            }

            50% {
                transform: translateY(-30px) rotate(180deg);
            }
        }

        /* تأثير التوهج للعناصر */
        body.space-theme .subject-btn {
            box-shadow: 0 0 10px rgba(0, 255, 255, 0.2);
        }

        body.space-theme .subject-btn:hover {
            box-shadow: 0 0 20px rgba(0, 255, 255, 0.4);
        }

        body.space-theme .challenge-option:hover {
            box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
        }

        body.space-theme footer {
            background: rgba(10, 10, 42, 0.9);
            border-top: 1px solid rgba(0, 255, 255, 0.2);
        }

        /* Ocean Theme - ثيم المحيط */
        body.ocean-theme {
            background: linear-gradient(180deg, #0a2942 0%, #051a2d 100%);
        }

        body.ocean-theme .navbar {
            background: rgba(10, 41, 66, 0.95);
            border-bottom: 2px solid rgba(0, 200, 255, 0.3);
        }

        body.ocean-theme .hero {
            background: linear-gradient(135deg, #0a2942 0%, #1a5a7a 50%, #0a4060 100%);
        }

        body.ocean-theme .section {
            background: linear-gradient(180deg, #0a2942 0%, #051a2d 100%);
        }

        body.ocean-theme h1,
        body.ocean-theme h2,
        body.ocean-theme h3 {
            color: #00d4ff;
            text-shadow: 0 0 15px rgba(0, 212, 255, 0.4);
        }

        body.ocean-theme .subject-card {
            background: linear-gradient(145deg, rgba(10, 60, 90, 0.8) 0%, rgba(5, 40, 70, 0.6) 100%);
            border: 2px solid rgba(0, 200, 255, 0.2);
        }

        body.ocean-theme .subject-card:hover {
            border-color: rgba(0, 200, 255, 0.5);
            box-shadow: 0 0 30px rgba(0, 200, 255, 0.3);
        }

        /* Sunset Theme - ثيم الغروب */
        body.sunset-theme {
            background: linear-gradient(180deg, #2d1f3d 0%, #1a1020 100%);
        }

        body.sunset-theme .navbar {
            background: rgba(45, 31, 61, 0.95);
            border-bottom: 2px solid rgba(255, 120, 100, 0.3);
        }

        body.sunset-theme .hero {
            background: linear-gradient(135deg, #2d1f3d 0%, #6a3050 50%, #4a2040 100%);
        }

        body.sunset-theme .section {
            background: linear-gradient(180deg, #2d1f3d 0%, #1a1020 100%);
        }

        body.sunset-theme h1,
        body.sunset-theme h2,
        body.sunset-theme h3 {
            color: #ff9a6c;
            text-shadow: 0 0 15px rgba(255, 154, 108, 0.4);
        }

        body.sunset-theme .subject-card {
            background: linear-gradient(145deg, rgba(106, 48, 80, 0.8) 0%, rgba(74, 32, 64, 0.6) 100%);
            border: 2px solid rgba(255, 120, 100, 0.2);
        }

        body.sunset-theme .subject-card:hover {
            border-color: rgba(255, 120, 100, 0.5);
            box-shadow: 0 0 30px rgba(255, 120, 100, 0.3);
        }

        /* Pyramids Theme - ثيم الأهرامات المصرية */
        body.pyramids-theme {
            background: linear-gradient(180deg, #1a1510 0%, #2d2015 50%, #1a1510 100%);
        }

        body.pyramids-theme .navbar {
            background: rgba(45, 32, 21, 0.95);
            border-bottom: 2px solid rgba(212, 175, 55, 0.4);
        }

        body.pyramids-theme .hero {
            background: linear-gradient(135deg, #2d2015 0%, #4a3520 50%, #2d2015 100%);
        }

        body.pyramids-theme .section {
            background: linear-gradient(180deg, #1a1510 0%, #2d2015 100%);
        }

        body.pyramids-theme h1,
        body.pyramids-theme h2,
        body.pyramids-theme h3 {
            color: #d4af37;
            text-shadow: 0 0 15px rgba(212, 175, 55, 0.5);
        }

        body.pyramids-theme .subject-card {
            background: linear-gradient(145deg, rgba(74, 53, 32, 0.9) 0%, rgba(45, 32, 21, 0.7) 100%);
            border: 2px solid rgba(212, 175, 55, 0.3);
        }

        body.pyramids-theme .subject-card:hover {
            border-color: rgba(212, 175, 55, 0.7);
            box-shadow: 0 0 30px rgba(212, 175, 55, 0.4);
        }

        body.pyramids-theme .btn-primary {
            background: linear-gradient(45deg, #d4af37, #aa8a2e);
            color: #1a1510;
        }

        /* 3D Pyramids */
        .pyramid-3d {
            position: fixed;
            z-index: -1;
            display: none;
        }

        body.pyramids-theme .pyramid-3d {
            display: block;
        }

        .pyramid-1 {
            bottom: 0;
            right: 10%;
            width: 0;
            height: 0;
            border-left: 120px solid transparent;
            border-right: 120px solid transparent;
            border-bottom: 200px solid rgba(139, 107, 55, 0.6);
            filter: drop-shadow(0 0 20px rgba(212, 175, 55, 0.3));
        }

        .pyramid-2 {
            bottom: 0;
            right: 25%;
            width: 0;
            height: 0;
            border-left: 80px solid transparent;
            border-right: 80px solid transparent;
            border-bottom: 140px solid rgba(160, 125, 65, 0.5);
            filter: drop-shadow(0 0 15px rgba(212, 175, 55, 0.2));
        }

        .pyramid-3 {
            bottom: 0;
            left: 15%;
            width: 0;
            height: 0;
            border-left: 100px solid transparent;
            border-right: 100px solid transparent;
            border-bottom: 170px solid rgba(120, 90, 45, 0.5);
            filter: drop-shadow(0 0 18px rgba(212, 175, 55, 0.25));
        }

        /* Desert sand effect */
        body.pyramids-theme::after {
            content: '';
            position: fixed;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 80px;
            background: linear-gradient(to top, rgba(194, 154, 80, 0.3), transparent);
            pointer-events: none;
            z-index: -1;
        }

        /* Mummy decorations on cards */
        body.pyramids-theme .subject-card::before {
            content: '🎃';
            position: absolute;
            top: -12px;
            right: -12px;
            font-size: 1.5rem;
            animation: floatMummy 3s ease-in-out infinite;
        }

        body.pyramids-theme .subject-card:nth-child(odd)::before {
            content: '👻';
        }

        body.pyramids-theme .subject-card:nth-child(3n)::before {
            content: '🏺';
        }

        body.pyramids-theme .subject-card:nth-child(4n)::before {
            content: '⚱️';
        }

        @keyframes floatMummy {

            0%,
            100% {
                transform: translateY(0) rotate(0deg);
            }

            50% {
                transform: translateY(-5px) rotate(5deg);
            }
        }

        /* Hieroglyphic border */
        body.pyramids-theme .subject-card {
            position: relative;
            overflow: visible;
            /* Mummy bandages/wrappings pattern */
            background-image:
                repeating-linear-gradient(-45deg,
                    transparent,
                    transparent 8px,
                    rgba(194, 165, 110, 0.15) 8px,
                    rgba(194, 165, 110, 0.15) 12px),
                linear-gradient(145deg, rgba(74, 53, 32, 0.9) 0%, rgba(45, 32, 21, 0.7) 100%);
            border: 2px solid rgba(212, 175, 55, 0.3);
            box-shadow:
                inset 0 0 20px rgba(139, 107, 55, 0.3),
                0 5px 20px rgba(0, 0, 0, 0.3);
        }

        body.pyramids-theme .subject-card:hover {
            background-image:
                repeating-linear-gradient(-45deg,
                    transparent,
                    transparent 8px,
                    rgba(212, 175, 55, 0.2) 8px,
                    rgba(212, 175, 55, 0.2) 12px),
                linear-gradient(145deg, rgba(90, 65, 40, 0.9) 0%, rgba(55, 40, 25, 0.8) 100%);
            border-color: rgba(212, 175, 55, 0.7);
            box-shadow:
                inset 0 0 30px rgba(212, 175, 55, 0.3),
                0 0 30px rgba(212, 175, 55, 0.4);
        }

        body.pyramids-theme .subject-card::after {
            content: '𓂀 𓃭 𓅓 𓆣';
            position: absolute;
            bottom: -8px;
            left: 50%;
            transform: translateX(-50%);
            font-size: 0.8rem;
            color: rgba(212, 175, 55, 0.5);
            white-space: nowrap;
        }

        body.pyramids-theme .navbar::after {
            content: '☥ 𓂀 𓃭 𓅓 𓆣 𓏏 ☥';
            position: absolute;
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            font-size: 1rem;
            color: rgba(212, 175, 55, 0.4);
        }

        /* Winter Theme - ثيم الشتاء */
        body.winter-theme {
            background: linear-gradient(180deg, #151922 0%, #1e2832 100%);
        }

        body.winter-theme .navbar {
            background: rgba(21, 25, 34, 0.95);
            border-bottom: 2px solid rgba(135, 206, 250, 0.3);
            /* Icy blue border */
        }

        body.winter-theme .hero {
            background: linear-gradient(135deg, #1e2832 0%, #2c3e50 100%);
        }

        body.winter-theme .section {
            background: transparent;
        }

        body.winter-theme h1,
        body.winter-theme h2,
        body.winter-theme h3 {
            color: #87cefa;
            /* Light Sky Blue */
            text-shadow: 0 0 10px rgba(135, 206, 250, 0.5);
        }

        body.winter-theme .subject-card {
            background: rgba(255, 255, 255, 0.05);
            backdrop-filter: blur(5px);
            border: 1px solid rgba(135, 206, 250, 0.2);
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
        }

        body.winter-theme .subject-card:hover {
            border-color: rgba(135, 206, 250, 0.6);
            box-shadow: 0 0 25px rgba(135, 206, 250, 0.2);
            background: rgba(255, 255, 255, 0.08);
        }

        body.winter-theme .btn-primary {
            background: linear-gradient(135deg, #5da2d5, #87cefa);
            color: #151922;
        }

        /* Snowflake Animation */
        .snowflake {
            color: #fff;
            font-size: 1.5rem;
            font-family: Arial, sans-serif;
            text-shadow: 0 0 5px #000;
            position: fixed;
            top: -10%;
            z-index: 9999;
            user-select: none;
            cursor: default;
            animation-name: snowflakes-fall, snowflakes-shake;
            animation-duration: 10s, 3s;
            animation-timing-function: linear, ease-in-out;
            animation-iteration-count: infinite, infinite;
            animation-play-state: running, running;
            display: none;
            /* Hidden by default */
        }

        body.winter-theme .snowflake {
            display: block;
        }

        @keyframes snowflakes-fall {
            0% {
                top: -10%;
            }

            100% {
                top: 100%;
            }
        }

        @keyframes snowflakes-shake {

            0%,
            100% {
                transform: translateX(0);
            }

            50% {
                transform: translateX(80px);
            }
        }

        .snowflake:nth-of-type(1) {
            left: 1%;
            animation-delay: 0s, 0s;
        }

        .snowflake:nth-of-type(2) {
            left: 10%;
            animation-delay: 1s, 1s;
        }

        .snowflake:nth-of-type(3) {
            left: 20%;
            animation-delay: 6s, .5s;
        }

        .snowflake:nth-of-type(4) {
            left: 30%;
            animation-delay: 4s, 2s;
        }

        .snowflake:nth-of-type(5) {
            left: 40%;
            animation-delay: 2s, 2s;
        }

        .snowflake:nth-of-type(6) {
            left: 50%;
            animation-delay: 8s, 3s;
        }

        .snowflake:nth-of-type(7) {
            left: 60%;
            animation-delay: 6s, 2s;
        }

        .snowflake:nth-of-type(8) {
            left: 70%;
            animation-delay: 2.5s, 1s;
        }

        .snowflake:nth-of-type(9) {
            left: 80%;
            animation-delay: 1s, 0s;
        }

        .snowflake:nth-of-type(10) {
            left: 90%;
            animation-delay: 3s, 1.5s;
        }

        /* Scroll Rocket Button */
        .scroll-rocket {
            position: fixed;
            bottom: 40px;
            right: 20px;
            width: 55px;
            height: 55px;
            border-radius: 50%;
            background: linear-gradient(135deg, #ff6b6b, #ffc107);
            border: none;
            cursor: pointer;
            display: none;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            color: white;
            box-shadow: 0 5px 25px rgba(255, 107, 107, 0.5);
            z-index: 1000;
            transition: all 0.3s ease;
        }

        body.space-theme .scroll-rocket {
            display: flex;
            background: linear-gradient(135deg, #00ffff, #4a1a6a);
            box-shadow: 0 0 30px rgba(0, 255, 255, 0.5);
        }

        .scroll-rocket:hover {
            transform: scale(1.15) translateY(-5px);
        }

        .scroll-rocket.going-down {
            transform: rotate(180deg);
        }

        .scroll-rocket.going-down:hover {
            transform: rotate(180deg) scale(1.15) translateY(5px);
        }

        /* Smooth Theme Transitions */
        body {
            transition: background 0.5s ease, color 0.3s ease;
        }

        .navbar,
        .section,
        .hero,
        .subject-card,
        footer {
            transition: all 0.5s ease;
        }

        /* Theme Toggle Button */
        .theme-toggle {
            position: fixed;
            bottom: 100px;
            left: 20px;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background: linear-gradient(135deg, #667eea, #764ba2);
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.3rem;
            color: white;
            box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
            z-index: 1001;
            transition: all 0.3s ease;
        }

        .theme-toggle:hover {
            transform: scale(1.1);
            box-shadow: 0 8px 30px rgba(102, 126, 234, 0.6);
        }

        /* Nav Icon Item - for dropdown positioning */
        .nav-icon-item {
            position: relative;
        }

        /* Theme Menu */
        .theme-menu {
            position: absolute;
            top: 100%;
            left: 50%;
            transform: translateX(-50%) translateY(10px);
            background: rgba(26, 26, 46, 0.98);
            border-radius: 15px;
            padding: 15px;
            box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
            border: 1px solid rgba(255, 255, 255, 0.1);
            z-index: 2000;
            display: none;
            flex-direction: column;
            gap: 10px;
            backdrop-filter: blur(10px);
            opacity: 0;
            transition: all 0.3s ease;
            min-width: 180px;
        }

        .theme-menu.active {
            display: flex;
            transform: translateX(-50%) translateY(5px);
            opacity: 1;
        }

        .theme-menu-title {
            color: white;
            font-size: 0.9rem;
            text-align: center;
            margin-bottom: 5px;
            padding-bottom: 10px;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .theme-option {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px 15px;
            border: none;
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.05);
            color: white;
            cursor: pointer;
            transition: all 0.3s ease;
            font-family: 'Cairo', sans-serif;
        }

        .theme-option:hover {
            background: rgba(255, 255, 255, 0.15);
            transform: translateX(5px);
        }

        .theme-option.active {
            background: linear-gradient(135deg, #38ef7d, #11998e);
            color: #0a0a2a;
        }

        .theme-option i {
            width: 25px;
            text-align: center;
        }

        /* User Profile Button */
        .user-profile-btn {
            position: fixed;
            bottom: 160px;
            left: 20px;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background: linear-gradient(135deg, #38ef7d, #11998e);
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.3rem;
            color: white;
            box-shadow: 0 5px 20px rgba(56, 239, 125, 0.4);
            z-index: 1000;
            transition: all 0.3s ease;
        }

        .user-profile-btn:hover {
            transform: scale(1.1);
        }

        /* User Profile Modal */
        .user-profile-modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            z-index: 3000;
            align-items: center;
            justify-content: center;
        }

        .user-profile-modal.active {
            display: flex;
        }

        .profile-content {
            background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
            border-radius: 20px;
            max-width: 400px;
            width: 90%;
            padding: 30px;
            border: 1px solid rgba(56, 239, 125, 0.3);
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
        }

        .profile-header {
            text-align: center;
            margin-bottom: 25px;
        }

        .profile-avatar {
            width: 80px;
            height: 80px;
            border-radius: 50%;
            background: linear-gradient(135deg, #38ef7d, #11998e);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 2.5rem;
            margin: 0 auto 15px;
            color: white;
        }

        .profile-header h2 {
            color: white;
            margin-bottom: 5px;
        }

        .profile-id {
            color: rgba(255, 255, 255, 0.5);
            font-size: 0.85rem;
            font-family: monospace;
        }

        .profile-form {
            margin-bottom: 20px;
        }

        .profile-form input {
            width: 100%;
            padding: 15px;
            background: rgba(255, 255, 255, 0.08);
            border: 2px solid rgba(56, 239, 125, 0.3);
            border-radius: 12px;
            color: white;
            font-size: 1rem;
            text-align: center;
            margin-bottom: 15px;
        }

        .profile-form input:focus {
            outline: none;
            border-color: #38ef7d;
        }

        .profile-stats {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 15px;
            margin-bottom: 20px;
        }

        .stat-item {
            background: rgba(255, 255, 255, 0.05);
            padding: 15px;
            border-radius: 10px;
            text-align: center;
        }

        .stat-value {
            font-size: 1.5rem;
            font-weight: bold;
            color: #38ef7d;
        }

        .stat-label {
            color: rgba(255, 255, 255, 0.6);
            font-size: 0.85rem;
        }

        .profile-buttons {
            display: flex;
            gap: 10px;
        }

        .profile-btn {
            flex: 1;
            padding: 12px;
            border: none;
            border-radius: 10px;
            font-family: 'Cairo', sans-serif;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .profile-btn.save-btn {
            background: linear-gradient(135deg, #38ef7d, #11998e);
            color: white;
        }

        .profile-btn.restore-btn {
            background: rgba(255, 193, 7, 0.1);
            color: #ffc107;
            border: 1px solid rgba(255, 193, 7, 0.3);
        }

        .profile-btn.close-btn {
            background: rgba(255, 255, 255, 0.1);
            color: white;
        }

        /* Leaderboard Tabs */
        .leaderboard-tabs {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            justify-content: center;
            margin-bottom: 30px;
            padding: 20px;
            background: rgba(255, 255, 255, 0.03);
            border-radius: 20px;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }

        .lb-tab {
            padding: 12px 20px;
            border: 2px solid rgba(255, 255, 255, 0.1);
            border-radius: 30px;
            background: rgba(255, 255, 255, 0.05);
            color: rgba(255, 255, 255, 0.7);
            font-family: 'Cairo', sans-serif;
            font-size: 0.95rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .lb-tab:hover {
            background: rgba(255, 255, 255, 0.1);
            border-color: rgba(255, 255, 255, 0.2);
            color: #fff;
        }

        .lb-tab.active {
            background: linear-gradient(135deg, #667eea, #764ba2);
            border-color: transparent;
            color: #fff;
            box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
        }

        .lb-tab i {
            font-size: 1rem;
        }

        .current-subject-title {
            text-align: center;
            padding: 15px;
            background: rgba(102, 126, 234, 0.1);
            border-radius: 15px;
            margin-bottom: 20px;
            color: #667eea;
            font-weight: 600;
            font-size: 1.1rem;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }

        @media (max-width: 768px) {
            .leaderboard-tabs {
                padding: 15px;
            }

            .lb-tab {
                padding: 10px 15px;
                font-size: 0.85rem;
            }
        }
    
/* ============================================
   ACCESSIBILITY STYLES
   ============================================ */

/* Skip to main content link */
.skip-link {
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 12px 24px;
    border-radius: 0 0 12px 12px;
    font-weight: 600;
    text-decoration: none;
    z-index: 100000;
    transition: top 0.3s ease;
    font-family: 'Cairo', sans-serif;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.skip-link:focus {
    top: 0;
    outline: none;
}

/* Enhanced focus styles for keyboard navigation */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
    outline: 3px solid #667eea;
    outline-offset: 3px;
    border-radius: 4px;
}

/* Focus within cards */
.subject-card:focus-within,
.bank-question-card:focus-within {
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.5);
}

/* Reduced 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;
    }
}

/* Screen reader only text (for ARIA descriptions) */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}