:root {
            --primary-green: #90EE90;
            --dark-green: #228B22;
            --accent-green: #c8f7c8;
            --golden-yellow: #DAA520;
            --light-yellow: #F4D03F;
            --text-dark: #2C1810;
            --text-medium: #5D4037;
            --white: #FFFFFF;
            --shadow: rgba(0, 0, 0, 0.2);
            --overlay: rgba(0, 0, 0, 0.5);
            --earth-brown: #8B4513;
        }

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

        body {
            font-family: 'Quicksand', sans-serif;
            min-height: 100vh;
            overflow-x: hidden;
        }

        .app-container {
            display: flex;
            min-height: 100vh;
        }

        .sidebar {
            width: 320px;
            min-width: 320px;
            background: linear-gradient(180deg, var(--accent-green) 0%, var(--primary-green) 100%);
            padding: 20px;
            display: flex;
            flex-direction: column;
            gap: 15px;
            box-shadow: 4px 0 20px var(--shadow);
            z-index: 100;
        }

        .sidebar-overlay {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, 0.45);
            z-index: 99;
            opacity: 0;
            transition: opacity 0.3s ease;
        }

        .sidebar-overlay.active {
            opacity: 1;
        }

        @media (max-width: 992px) {
            .sidebar-overlay.active {
                display: block;
            }
        }

        .sidebar-close-btn {
            display: none;
            align-self: flex-end;
            background: none;
            border: 2px solid var(--dark-green);
            border-radius: 8px;
            font-size: 1.2rem;
            color: var(--text-dark);
            cursor: pointer;
            padding: 4px 10px;
            line-height: 1;
            transition: background 0.2s ease;
        }

        .sidebar-close-btn:hover {
            background: rgba(0,0,0,0.08);
        }

        .logo-section { text-align: center; padding-bottom: 10px; }

        .logo-img {
            width: 180px;
            height: auto;
            filter: drop-shadow(2px 4px 6px var(--shadow));
            transition: transform 0.3s ease;
        }

        .logo-img:hover { transform: scale(1.05) rotate(-2deg); }

        .auth-buttons {
            display: flex;
            gap: 15px;
            justify-content: center;
            margin-bottom: 10px;
        }

        .auth-btn {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.1rem;
            font-weight: 600;
            padding: 10px 25px;
            border: none;
            border-radius: 25px;
            cursor: pointer;
            transition: all 0.3s ease;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        .login-btn {
            background: var(--golden-yellow);
            color: var(--text-dark);
            box-shadow: 0 4px 0 #B8860B, 0 6px 10px var(--shadow);
        }

        .login-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 0 #B8860B, 0 8px 15px var(--shadow);
        }

        .signup-btn {
            background: var(--dark-green);
            color: var(--white);
            box-shadow: 0 4px 0 #1a6b1a, 0 6px 10px var(--shadow);
        }

        .signup-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 0 #1a6b1a, 0 8px 15px var(--shadow);
        }

        .menu-card {
            background: var(--accent-green);
            border-radius: 15px;
            padding: 15px;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 3px solid var(--dark-green);
            box-shadow: 0 4px 8px var(--shadow);
        }

        .menu-card:hover {
            transform: translateY(-5px) scale(1.02);
            box-shadow: 0 8px 20px var(--shadow);
        }

        .menu-card img {
            width: 100%;
            height: auto;
            border-radius: 10px;
            margin-bottom: 10px;
        }

        .menu-card h3 {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.4rem;
            color: var(--text-dark);
            text-align: center;
            text-shadow: 1px 1px 0 var(--white);
        }

        .leaf-divider {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            padding: 5px 0;
        }

        .leaf {
            width: 30px;
            height: 15px;
            background: var(--dark-green);
            border-radius: 0 50% 50% 50%;
            transform: rotate(-30deg);
        }

        .leaf:last-child { transform: rotate(30deg) scaleX(-1); }

        .bottom-menu-item {
            background: var(--accent-green);
            border-radius: 10px;
            padding: 15px 20px;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 2px solid var(--dark-green);
        }

        .bottom-menu-item:hover {
            background: var(--primary-green);
            transform: translateX(5px);
        }

        .bottom-menu-item h3 {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.2rem;
            color: var(--text-dark);
        }

        .main-content {
            flex: 1;
            position: relative;
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
        }

        /* Mobile first: 768px width */
        .main-content {
            background-image: url('../assets/images/optimized/background/bg-768w.jpg');
        }

        /* WebP support detection */
        @supports (background-image: url('test.webp')) {
            .main-content {
                background-image: url('../assets/images/optimized/background/bg-768w.webp');
            }
        }

        /* Tablet: 1280px width */
        @media (min-width: 769px) {
            .main-content {
                background-image: url('../assets/images/optimized/background/bg-1280w.jpg');
            }

            @supports (background-image: url('test.webp')) {
                .main-content {
                    background-image: url('../assets/images/optimized/background/bg-1280w.webp');
                }
            }
        }

        /* Desktop: 1920px width */
        @media (min-width: 1281px) {
            .main-content {
                background-image: url('../assets/images/optimized/background/bg-1920w.jpg');
            }

            @supports (background-image: url('test.webp')) {
                .main-content {
                    background-image: url('../assets/images/optimized/background/bg-1920w.webp');
                }
            }
        }

        .header {
            position: absolute;
            top: 0;
            right: 0;
            padding: 20px 30px;
            z-index: 50;
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .profile-section {
            display: flex;
            align-items: center;
            gap: 15px;
            background: rgba(255, 255, 255, 0.95);
            padding: 10px 20px;
            border-radius: 30px;
            box-shadow: 0 4px 15px var(--shadow);
        }

        .profile-avatar {
            width: 45px;
            height: 45px;
            background: var(--primary-green);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            border: 3px solid var(--dark-green);
        }

        .profile-avatar svg { width: 30px; height: 30px; fill: var(--text-dark); }

        .profile-info { display: flex; flex-direction: column; gap: 5px; }

        .profile-name {
            font-family: 'Fredoka', sans-serif;
            font-weight: 600;
            color: var(--text-dark);
            font-size: 1rem;
        }

        .xp-container { display: flex; align-items: center; gap: 8px; }

        .xp-label { font-size: 0.75rem; color: #B8860B; font-weight: 700; }

        .xp-bar {
            width: 120px;
            height: 12px;
            background: #e0e0e0;
            border-radius: 6px;
            overflow: hidden;
        }

        .xp-fill {
            height: 100%;
            background: linear-gradient(90deg, var(--golden-yellow), var(--light-yellow));
            border-radius: 6px;
            transition: width 0.3s ease-out;
        }

        .xp-text { font-size: 0.7rem; color: var(--text-medium); font-weight: 600; }

        .settings-btn {
            width: 40px;
            height: 40px;
            background: var(--white);
            border: none;
            border-radius: 50%;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 2px 8px var(--shadow);
            transition: all 0.3s ease;
        }

        .settings-btn:hover { transform: rotate(90deg); background: var(--accent-green); }
        .settings-btn svg { width: 22px; height: 22px; fill: var(--text-medium); }

        .modal-overlay {
            position: fixed;
            top: 0; left: 0;
            width: 100%; height: 100%;
            background: var(--overlay);
            display: none;
            justify-content: center;
            align-items: center;
            z-index: 1000;
            backdrop-filter: blur(5px);
        }

        .modal-overlay.active { display: flex; }

        .modal {
            background: linear-gradient(180deg, var(--accent-green) 0%, var(--primary-green) 100%);
            border-radius: 25px;
            padding: 30px 40px;
            max-width: 450px;
            width: 90%;
            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
            border: 4px solid var(--dark-green);
            max-height: 90vh;
            overflow-y: auto;
        }

        .modal-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 25px;
        }

        .modal-title {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.8rem;
            color: var(--text-dark);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .close-btn {
            width: 35px; height: 35px;
            background: var(--golden-yellow);
            border: none;
            border-radius: 50%;
            cursor: pointer;
            font-size: 1.5rem;
            color: var(--text-dark);
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 3px 0 #B8860B;
            transition: all 0.2s ease;
        }

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

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

        .form-group label {
            display: block;
            font-family: 'Fredoka', sans-serif;
            color: var(--text-dark);
            margin-bottom: 8px;
        }

        .form-group input, .form-group textarea {
            width: 100%;
            padding: 12px 15px;
            border: 3px solid var(--dark-green);
            border-radius: 12px;
            font-family: 'Quicksand', sans-serif;
            font-size: 1rem;
            background: var(--white);
        }

        .form-group input:focus, .form-group textarea:focus {
            outline: none;
            border-color: var(--golden-yellow);
        }

        .form-group textarea { min-height: 120px; resize: vertical; }

        .submit-btn {
            width: 100%;
            padding: 18px;
            background: var(--golden-yellow);
            border: none;
            border-radius: 15px;
            font-family: 'Fredoka', sans-serif;
            font-size: 1.3rem;
            font-weight: 600;
            color: var(--text-dark);
            cursor: pointer;
            box-shadow: 0 5px 0 #B8860B;
            text-transform: uppercase;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            min-height: 56px;
            transition: all 0.3s ease;
        }

        .submit-btn:hover:not(:disabled) { transform: translateY(-3px); }
        .submit-btn:disabled {
            opacity: 0.7;
            cursor: not-allowed;
            transform: none;
        }

        /* Loading spinner for buttons */
        .btn-spinner {
            width: 22px;
            height: 22px;
            border: 3px solid rgba(0,0,0,0.2);
            border-top-color: var(--text-dark);
            border-radius: 50%;
            animation: spin 0.8s linear infinite;
        }
        @keyframes spin {
            to { transform: rotate(360deg); }
        }

        /* Password input wrapper with toggle */
        .password-input-wrapper {
            position: relative;
            display: flex;
            align-items: center;
        }
        .password-input-wrapper input {
            padding-right: 50px;
        }
        .password-toggle {
            position: absolute;
            right: 12px;
            background: none;
            border: none;
            cursor: pointer;
            padding: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 8px;
            transition: background 0.2s ease;
        }
        .password-toggle:hover {
            background: rgba(0,0,0,0.05);
        }
        .password-toggle svg {
            fill: var(--text-medium);
            transition: fill 0.2s ease;
        }
        .password-toggle:hover svg {
            fill: var(--dark-green);
        }
        .password-toggle.visible .eye-icon { display: none; }
        .password-toggle.visible .eye-off-icon { display: block !important; }

        /* Password hint text */
        .password-hint {
            font-size: 0.85rem;
            color: var(--text-medium);
            margin-top: 6px;
            padding-left: 4px;
        }

        /* Forgot Password Button - larger and more visible */
        .forgot-password-btn {
            width: 100%;
            padding: 14px 20px;
            background: transparent;
            border: 2px dashed var(--dark-green);
            border-radius: 12px;
            font-family: 'Fredoka', sans-serif;
            font-size: 1.1rem;
            font-weight: 500;
            color: var(--text-dark);
            cursor: pointer;
            margin-bottom: 15px;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }
        .forgot-password-btn:hover {
            background: rgba(218, 165, 32, 0.15);
            border-color: var(--golden-yellow);
            transform: translateY(-2px);
        }

        /* Back to login button */
        .back-to-login-btn {
            width: 100%;
            padding: 14px 20px;
            background: transparent;
            border: none;
            font-family: 'Fredoka', sans-serif;
            font-size: 1.1rem;
            font-weight: 500;
            color: var(--dark-green);
            cursor: pointer;
            margin-top: 15px;
            transition: all 0.3s ease;
            text-decoration: underline;
            text-underline-offset: 3px;
        }
        .back-to-login-btn:hover {
            color: #B8860B;  /* Darkened from var(--golden-yellow) for WCAG AA contrast */
        }

        /* Inline error messages */
        .error-message {
            background: #ffebee;
            border: 2px solid #f44336;
            border-radius: 12px;
            padding: 12px 16px;
            margin-bottom: 15px;
            color: #c62828;
            font-family: 'Quicksand', sans-serif;
            font-weight: 600;
            font-size: 0.95rem;
            display: none;
            align-items: center;
            gap: 10px;
            animation: shakeError 0.5s ease;
        }
        .error-message.show {
            display: flex;
        }
        .error-message::before {
            content: '⚠️';
            font-size: 1.2rem;
        }
        @keyframes shakeError {
            0%, 100% { transform: translateX(0); }
            20%, 60% { transform: translateX(-5px); }
            40%, 80% { transform: translateX(5px); }
        }

        /* Improved logout button */
        .logout-btn {
            width: 100%;
            padding: 14px 20px;
            background: linear-gradient(135deg, #ef5350 0%, #e53935 100%);
            border: none;
            border-radius: 12px;
            font-family: 'Fredoka', sans-serif;
            font-size: 1.1rem;
            font-weight: 600;
            color: white;
            cursor: pointer;
            box-shadow: 0 4px 0 #c62828, 0 6px 10px var(--shadow);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            transition: all 0.3s ease;
            margin-top: 10px;
        }
        .logout-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 0 #c62828, 0 8px 15px var(--shadow);
        }
        .logout-btn svg {
            flex-shrink: 0;
        }

        /* Select dropdown improvements */
        select {
            width: 100%;
            padding: 14px 15px;
            border: 3px solid var(--dark-green);
            border-radius: 12px;
            font-family: 'Quicksand', sans-serif;
            font-size: 1rem;
            background: white;
            color: var(--text-dark);
            cursor: pointer;
            appearance: none;
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='%23228B22'%3E%3Cpath d='M7 10l5 5 5-5z'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: right 12px center;
        }
        select:focus {
            outline: none;
            border-color: var(--golden-yellow);
        }

        /* ================================
           GDPR Consent Section
        ================================ */
        .gdpr-consent-section {
            margin: 16px 0 12px;
            padding: 14px;
            background: rgba(144, 238, 144, 0.08);
            border: 2px solid var(--earth-brown);
            border-radius: 12px;
        }
        .gdpr-consent-heading {
            font-family: 'Fredoka', sans-serif;
            font-size: 0.95rem;
            font-weight: 600;
            color: var(--text-dark);
            margin-bottom: 10px;
        }
        .gdpr-consent-item {
            display: flex;
            align-items: flex-start;
            gap: 10px;
            padding: 6px 0;
            cursor: pointer;
            font-size: 0.85rem;
            line-height: 1.4;
            color: var(--text-medium);
        }
        .gdpr-consent-item input[type="checkbox"] {
            width: 18px;
            height: 18px;
            min-width: 18px;
            margin-top: 1px;
            accent-color: var(--dark-green);
            cursor: pointer;
        }
        .gdpr-consent-item input[type="checkbox"]:disabled {
            opacity: 0.6;
            cursor: not-allowed;
        }
        .gdpr-consent-item strong {
            color: var(--text-dark);
        }
        .gdpr-consent-item a {
            color: var(--dark-green);
            text-decoration: underline;
            font-weight: 600;
        }
        .gdpr-consent-item a:hover {
            color: #B8860B;  /* Darkened from var(--golden-yellow) for WCAG AA contrast */
        }
        .gdpr-privacy-policy {
            margin-top: 8px;
            padding-top: 8px;
            border-top: 1px solid var(--earth-brown);
        }

        /* OAuth Divider */
        .oauth-divider {
            display: flex;
            align-items: center;
            margin: 20px 0;
            color: var(--text-medium);
        }
        .oauth-divider::before,
        .oauth-divider::after {
            content: '';
            flex: 1;
            border-bottom: 1px solid var(--earth-brown);
        }
        .oauth-divider span {
            padding: 0 15px;
            font-size: 0.9rem;
        }

        /* OAuth Button */
        .oauth-btn {
            width: 100%;
            padding: 12px 15px;
            border: 2px solid var(--earth-brown);
            border-radius: 15px;
            background: white;
            font-family: 'Fredoka', sans-serif;
            font-size: 1rem;
            font-weight: 500;
            color: var(--text-dark);
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            transition: all 0.3s ease;
        }
        .oauth-btn:hover {
            background: var(--cream);
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        .google-btn svg {
            flex-shrink: 0;
        }

        .map-modal { max-width: 900px; padding: 20px; }
        .map-image { width: 100%; border-radius: 15px; border: 4px solid var(--earth-brown); }

        .revise-modal { max-width: 600px; }
        .topics-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 15px; margin-top: 20px; }

        .topic-card {
            background: var(--white);
            border-radius: 15px;
            padding: 20px;
            text-align: center;
            border: 3px solid var(--dark-green);
            cursor: pointer;
            position: relative;
        }

        .topic-card:hover { transform: translateY(-5px); border-color: var(--golden-yellow); }
        .topic-card.completed { background: linear-gradient(135deg, var(--accent-green), var(--primary-green)); }

        .topic-card.completed::after {
            content: '✓';
            position: absolute;
            top: 10px; right: 10px;
            width: 25px; height: 25px;
            background: var(--golden-yellow);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
        }

        .topic-icon { font-size: 2.5rem; margin-bottom: 10px; }
        .topic-name { font-family: 'Fredoka', sans-serif; color: var(--text-dark); }
        .topic-status { font-size: 0.8rem; color: var(--text-medium); margin-top: 5px; }

        /* Game-ready card (playable game) */
        .topic-card.game-ready { border: 3px solid var(--golden-yellow); cursor: pointer; }
        .topic-card.game-ready:hover { background: linear-gradient(135deg, #FFF8E1, #FFECB3); }
        .topic-card.game-ready .game-status { color: #B8860B; font-weight: 700; }

        /* About Modal Styles */
        .about-modal { max-width: 700px; }
        
        .about-content {
            color: var(--text-dark);
            line-height: 1.7;
            font-size: 1rem;
        }
        
        .about-intro {
            display: flex;
            gap: 20px;
            margin-bottom: 20px;
        }
        
        .about-intro-text {
            flex: 1;
        }
        
        .about-intro-text strong {
            color: var(--text-dark);
        }
        
        .about-mascot {
            width: 150px;
            height: auto;
            border-radius: 15px;
            flex-shrink: 0;
        }
        
        .about-section-title {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.4rem;
            color: var(--dark-green);
            margin: 25px 0 12px 0;
            font-style: italic;
        }
        
        .about-content p {
            margin-bottom: 15px;
            color: #4a4a4a;
        }

        .feature-list {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            margin: 15px 0;
        }
        
        .feature-tag {
            background: var(--golden-yellow);
            padding: 10px 18px;
            border-radius: 25px;
            font-family: 'Quicksand', sans-serif;
            font-size: 0.95rem;
            font-weight: 600;
            color: var(--text-dark);
            display: flex;
            align-items: center;
            gap: 8px;
            box-shadow: 0 3px 0 #B8860B;
        }

        /* Mobile logo: shown next to hamburger button */
        .mobile-header-logo {
            display: none;
            position: fixed;
            top: 20px;
            left: 80px; /* hamburger left(20) + width(50) + gap(10) */
            z-index: 200;
            height: 50px;
            align-items: center;
            pointer-events: none; /* logo is decorative, not a click target */
        }
        .mobile-header-logo img {
            height: 46px;
            width: auto;
            filter: drop-shadow(0 2px 4px rgba(0,0,0,0.15));
        }

        .mobile-menu-toggle {
            display: none;
            position: fixed;
            top: 20px; left: 20px;
            z-index: 200;
            width: 50px; height: 50px;
            background: var(--primary-green);
            border: 3px solid var(--dark-green);
            border-radius: 12px;
            cursor: pointer;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            gap: 5px;
        }

        .mobile-menu-toggle span {
            width: 25px;
            height: 3px;
            background: var(--text-dark);
            border-radius: 2px;
            transition: all 0.3s ease;
        }

        /* Hamburger to X animation when active */
        .mobile-menu-toggle.active span:nth-child(1) {
            transform: rotate(45deg) translate(6px, 6px);
        }
        .mobile-menu-toggle.active span:nth-child(2) {
            opacity: 0;
        }
        .mobile-menu-toggle.active span:nth-child(3) {
            transform: rotate(-45deg) translate(6px, -6px);
        }

        /* Dropdown Menu Styles */
        .dropdown-menu {
            display: none;
            position: fixed;
            top: 80px;
            left: 20px;
            background: linear-gradient(135deg, #ffffff 0%, #f0fff0 100%);
            border: 3px solid var(--dark-green);
            border-radius: 16px;
            padding: 10px;
            z-index: 250;
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
            min-width: 180px;
            animation: slideDown 0.3s ease;
        }

        .dropdown-menu.active {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }

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

        .dropdown-item {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 14px 18px;
            background: var(--primary-green);
            border: 2px solid var(--dark-green);
            border-radius: 12px;
            font-family: 'Fredoka', sans-serif;
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-dark);
            cursor: pointer;
            text-decoration: none;
            transition: all 0.2s ease;
            box-shadow: 0 3px 0 var(--dark-green);
        }

        .dropdown-item:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 0 var(--dark-green);
            background: var(--accent-green);
        }

        .dropdown-item:active {
            transform: translateY(1px);
            box-shadow: 0 1px 0 var(--dark-green);
        }

        .dropdown-icon {
            font-size: 1.2rem;
        }

        .success-message {
            display: none;
            background: var(--golden-yellow);
            padding: 20px;
            border-radius: 15px;
            text-align: center;
            margin-top: 20px;
        }

        .success-message.show { display: block; }
        .success-message h4 { font-family: 'Fredoka', sans-serif; font-size: 1.5rem; margin-bottom: 10px; }

        @media (max-width: 992px) {
            .mobile-menu-toggle { display: flex; }
            .mobile-header-logo { display: flex; }
            .sidebar-close-btn { display: flex; }
            .sidebar {
                position: fixed;
                left: -350px; /* Push further off-screen to hide completely */
                top: 0;
                height: 100vh;
                transition: left 0.3s ease;
                overflow-y: auto;
                box-shadow: none; /* Remove shadow when hidden */
            }
            .sidebar.active {
                left: 0;
                box-shadow: 4px 0 20px var(--shadow); /* Restore shadow when visible */
            }
            .header { top: auto; bottom: 0; left: 0; right: 0; padding: 15px; background: rgba(255,255,255,0.95); justify-content: center; }

            /* Prevent horizontal scroll from sidebar */
            body, .app-container {
                overflow-x: hidden;
            }

            /* Topics section: leave room above sticky user-card footer (95px + 20px breathing) */
            .topics-preview {
                padding-bottom: 120px;
            }
        }

        @media (max-width: 600px) {
            .sidebar { width: 280px; left: -320px; } /* Extra margin to hide completely */
            .logo-img { width: 140px; }
            .auth-buttons { flex-direction: column; gap: 10px; }
            .auth-btn { width: 100%; }
            .topics-grid { grid-template-columns: 1fr; }
            .about-intro { flex-direction: column; }
            .about-mascot { width: 120px; align-self: center; }

            /* Better modal spacing on small screens */
            .modal { padding: 20px; width: 95%; }
            .modal-title { font-size: 1.5rem; }

            /* Ensure minimum touch targets (44px) */
            .close-btn { width: 44px; height: 44px; font-size: 1.8rem; }
            .settings-btn { width: 48px; height: 48px; }

            /* Better form inputs on mobile */
            .form-group input,
            .form-group textarea {
                font-size: 16px; /* Prevents zoom on iOS */
                padding: 14px;
            }
        }

        /* Extra small screens (iPhone SE, small Android) */
        @media (max-width: 375px) {
            .sidebar { width: 260px; left: -260px; }
            .modal { padding: 15px; }
            .modal-title { font-size: 1.3rem; }
            .auth-btn { font-size: 1rem; padding: 12px 20px; }
        }

        /* Safe area insets for iPhone notch */
        @supports (padding: max(0px)) {
            .header {
                padding-left: max(20px, env(safe-area-inset-left));
                padding-right: max(20px, env(safe-area-inset-right));
            }

            @media (max-width: 992px) {
                .header {
                    padding-bottom: max(15px, env(safe-area-inset-bottom));
                }
            }

            .sidebar {
                padding-top: max(20px, env(safe-area-inset-top));
                padding-bottom: max(20px, env(safe-area-inset-bottom));
            }
        }

        /* Picture element compatibility */
        picture {
            display: contents;
        }

        /* Logout notification toast */
        .logout-notification {
            position: fixed;
            top: 20px;
            left: 50%;
            transform: translateX(-50%) translateY(-100px);
            background: linear-gradient(135deg, var(--primary-green) 0%, var(--dark-green) 100%);
            color: white;
            padding: 16px 32px;
            border-radius: 50px;
            font-family: 'Fredoka', sans-serif;
            font-size: 1.2rem;
            font-weight: 600;
            box-shadow: 0 8px 32px rgba(0,0,0,0.3);
            z-index: 9999;
            opacity: 0;
            transition: all 0.3s ease;
        }
        .logout-notification.show {
            transform: translateX(-50%) translateY(0);
            opacity: 1;
        }

        /* Improved form input accessibility */
        .form-group input:focus,
        .form-group textarea:focus,
        select:focus {
            outline: 3px solid var(--golden-yellow);
            outline-offset: 2px;
            border-color: var(--dark-green);
        }

        /* Larger touch targets for mobile */
        @media (max-width: 768px) {
            .form-group input,
            .form-group textarea,
            select {
                padding: 16px;
                font-size: 16px; /* Prevents iOS zoom */
                min-height: 52px;
            }

            .submit-btn {
                padding: 18px;
                font-size: 1.2rem;
                min-height: 56px;
            }

            .password-toggle {
                padding: 12px;
                right: 8px;
            }

            .password-toggle svg {
                width: 26px;
                height: 26px;
            }

            .forgot-password-btn {
                padding: 16px;
                font-size: 1.1rem;
                min-height: 52px;
            }

            .oauth-btn {
                padding: 16px;
                min-height: 52px;
            }

            .close-btn {
                width: 48px;
                height: 48px;
                font-size: 2rem;
            }

            .logout-btn {
                padding: 16px;
                min-height: 52px;
            }
        }

        /* Focus visible for keyboard users */
        .submit-btn:focus-visible,
        .oauth-btn:focus-visible,
        .forgot-password-btn:focus-visible,
        .password-toggle:focus-visible,
        .close-btn:focus-visible,
        .logout-btn:focus-visible {
            outline: 3px solid var(--golden-yellow);
            outline-offset: 3px;
        }

        /* ========================================
           HERO WELCOME SECTION
           ======================================== */

        .hero-welcome {
            padding: 30px 40px 60px;
            max-width: 900px;
            margin: 0 auto;
            animation: fadeInUp 0.8s ease-out;
        }

        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .hero-content {
            background: linear-gradient(145deg, rgba(255,255,255,0.75) 0%, rgba(200,247,200,0.65) 100%);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border-radius: 30px;
            padding: 40px 45px;
            border: 3px solid rgba(34,139,34,0.6);
            box-shadow:
                0 8px 32px rgba(0,0,0,0.15),
                inset 0 1px 0 rgba(255,255,255,0.6);
            position: relative;
            overflow: hidden;
        }

        .hero-content::before {
            content: '';
            position: absolute;
            top: -50%;
            right: -30%;
            width: 300px;
            height: 300px;
            background: radial-gradient(circle, rgba(218,165,32,0.15) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }

        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            background: linear-gradient(135deg, var(--golden-yellow) 0%, #f4d03f 100%);
            padding: 10px 22px;
            border-radius: 50px;
            margin-bottom: 25px;
            box-shadow: 0 4px 0 #B8860B, 0 6px 15px rgba(218,165,32,0.3);
            animation: badgeBounce 2s ease-in-out infinite;
        }

        @keyframes badgeBounce {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-5px); }
        }

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

        .badge-text {
            font-family: 'Fredoka', sans-serif;
            font-weight: 600;
            font-size: 0.95rem;
            color: var(--text-dark);
            letter-spacing: 0.5px;
            text-transform: uppercase;
        }

        .hero-title {
            margin-bottom: 20px;
        }

        .title-line {
            display: block;
            font-family: 'Fredoka', sans-serif;
            font-size: 2.8rem;
            font-weight: 700;
            color: var(--text-dark);
            line-height: 1.1;
            text-shadow: 2px 2px 0 rgba(255,255,255,0.8);
        }

        .title-line.highlight {
            color: var(--dark-green);
            position: relative;
        }

        .title-line.highlight::after {
            content: '';
            position: absolute;
            bottom: 5px;
            left: 0;
            width: 100%;
            height: 12px;
            background: linear-gradient(90deg, rgba(218,165,32,0.4) 0%, rgba(218,165,32,0.1) 100%);
            border-radius: 6px;
            z-index: -1;
        }

        .hero-description {
            font-family: 'Quicksand', sans-serif;
            font-size: 17px;  /* Apple HIG: primary text 17pt */
            font-weight: 500;
            color: var(--text-medium);
            line-height: 1.6;  /* Apple HIG: 1.4-1.6x body text */
            margin-bottom: 30px;
            max-width: 550px;
        }

        .hero-cta {
            display: flex;
            gap: 15px;
            flex-wrap: wrap;
        }

        .cta-primary {
            display: inline-flex;
            align-items: center;
            gap: 12px;
            background: linear-gradient(135deg, var(--dark-green) 0%, #1a6b1a 100%);
            color: white;
            font-family: 'Fredoka', sans-serif;
            font-size: 1.2rem;
            font-weight: 600;
            padding: 16px 32px;
            border-radius: 50px;
            text-decoration: none;
            border: none;
            cursor: pointer;
            box-shadow:
                0 6px 0 #145214,
                0 8px 20px rgba(34,139,34,0.4);
            transition: all 0.2s ease;
        }

        .cta-primary:hover {
            transform: translateY(-3px);
            box-shadow:
                0 9px 0 #145214,
                0 12px 30px rgba(34,139,34,0.5);
        }

        .cta-primary:active {
            transform: translateY(2px);
            box-shadow:
                0 3px 0 #145214,
                0 5px 15px rgba(34,139,34,0.4);
        }

        .cta-icon {
            font-size: 1.4rem;
        }

        .cta-secondary {
            display: inline-flex;
            align-items: center;
            background: transparent;
            color: var(--dark-green);
            font-family: 'Fredoka', sans-serif;
            font-size: 1.1rem;
            font-weight: 600;
            padding: 16px 28px;
            border-radius: 50px;
            border: 3px solid var(--dark-green);
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .cta-secondary:hover {
            background: var(--accent-green);
            transform: translateY(-2px);
        }

        /* Feature Showcase */
        .feature-showcase {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
            margin-top: 35px;
        }

        .feature-card {
            background: linear-gradient(145deg, rgba(255,255,255,0.7) 0%, rgba(248,255,248,0.6) 100%);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            border-radius: 20px;
            padding: 25px 20px;
            border: 2px solid rgba(34,139,34,0.5);
            box-shadow:
                0 8px 32px rgba(0,0,0,0.1),
                inset 0 1px 0 rgba(255,255,255,0.5);
            text-align: center;
            transition: all 0.3s ease;
            animation: cardSlideUp 0.6s ease-out backwards;
            animation-delay: var(--delay);
        }

        @keyframes cardSlideUp {
            from {
                opacity: 0;
                transform: translateY(40px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .feature-card:hover {
            transform: translateY(-8px) rotate(-1deg);
            background: linear-gradient(145deg, rgba(255,255,255,0.85) 0%, rgba(248,255,248,0.75) 100%);
            box-shadow:
                0 12px 40px rgba(0,0,0,0.2),
                inset 0 1px 0 rgba(255,255,255,0.7);
        }

        .feature-icon-wrap {
            width: 60px;
            height: 60px;
            background: linear-gradient(135deg, var(--golden-yellow) 0%, #f4d03f 100%);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 15px;
            box-shadow: 0 4px 0 #B8860B;
        }

        .feature-icon {
            font-size: 1.8rem;
        }

        .feature-card h3 {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--text-dark);
            margin-bottom: 10px;
        }

        .feature-card p {
            font-family: 'Quicksand', sans-serif;
            font-size: 15px;  /* Apple HIG: secondary text 15pt */
            color: var(--text-medium);
            line-height: 1.5;
        }

        /* Topics Preview */
        .topics-preview {
            margin-top: 40px;
            text-align: center;
        }

        .section-title {
            font-family: 'Fredoka', sans-serif;
            font-size: 1.6rem;
            font-weight: 600;
            color: var(--text-dark);
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 15px;
            text-shadow: 2px 2px 4px rgba(255,255,255,0.8);
        }

        .title-decoration {
            font-size: 1.2rem;
            opacity: 0.8;
        }

        .topic-pills {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            justify-content: center;
        }

        .topic-pill {
            background: linear-gradient(145deg, rgba(255,255,255,0.7) 0%, rgba(200,247,200,0.6) 100%);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            font-family: 'Fredoka', sans-serif;
            font-size: 1rem;
            font-weight: 500;
            color: var(--text-dark);
            padding: 12px 24px;
            border-radius: 50px;
            border: 2px solid rgba(34,139,34,0.5);
            box-shadow:
                0 4px 16px rgba(0,0,0,0.1),
                inset 0 1px 0 rgba(255,255,255,0.5);
            transition: all 0.2s ease;
            cursor: pointer;
            text-decoration: none;
        }

        .topic-pill:hover {
            transform: translateY(-3px) scale(1.05);
            background: linear-gradient(145deg, rgba(218,165,32,0.85) 0%, rgba(244,208,63,0.8) 100%);
            box-shadow:
                0 8px 24px rgba(0,0,0,0.15),
                inset 0 1px 0 rgba(255,255,255,0.6);
        }

        /* ========================================
           APPLE HIG RESPONSIVE RULES
           iOS / iPad / Desktop compliance
           ======================================== */

        /* --- iPad Pro Landscape (1366x1024) + Large Desktop --- */
        @media (min-width: 1200px) {
            .hero-welcome {
                max-width: 1000px;
            }
            .feature-showcase {
                grid-template-columns: repeat(4, 1fr);
                gap: 20px;
            }
        }

        /* --- iPad Landscape (1194x834 / 1180x820) --- */
        @media (min-width: 993px) and (max-width: 1199px) {
            .feature-showcase {
                grid-template-columns: repeat(4, 1fr);
                gap: 16px;  /* Apple HIG: 16px grid margins */
            }
        }

        /* --- iPad Portrait (834x1194 / 820x1180 / 810x1080) --- */
        @media (min-width: 769px) and (max-width: 992px) {
            .hero-welcome {
                padding: 30px 20px 60px;
                max-width: 760px;
            }

            .hero-content {
                padding: 32px 28px;
            }

            .title-line {
                font-size: 2.4rem;
            }

            .feature-showcase {
                grid-template-columns: repeat(2, 1fr);
                gap: 16px;
            }

            .feature-card {
                padding: 24px 20px;
            }
        }

        /* --- iPhone Landscape / Small Tablet (568-768px) --- */
        @media (max-width: 768px) {
            .hero-welcome {
                padding: 100px 16px 80px;  /* Apple HIG: 16px margin from edges */
            }

            .hero-content {
                padding: 28px 20px;
                border-radius: 24px;
            }

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

            .hero-description {
                font-size: 16px;  /* Apple HIG: min 16px prevents iOS zoom */
            }

            .feature-showcase {
                grid-template-columns: repeat(2, 1fr);
                gap: 12px;  /* Apple HIG: 10px min between targets */
            }
        }

        /* --- iPhone Portrait (up to 540px covers 390-430px real devices + Playwright's scaled viewport) --- */
        @media (max-width: 540px) {
            .hero-welcome {
                padding: 70px 16px 20px;  /* reduced top: hamburger is 50px+20px=70px; bottom handled by topics-preview padding */
            }

            .hero-content {
                padding: 24px 16px;  /* Apple HIG: 16px horizontal padding */
                border-radius: 20px;
            }

            .hero-badge {
                padding: 10px 18px;
                min-height: 44px;  /* Apple HIG: 44pt min touch target */
            }

            .badge-text {
                font-size: 13px;  /* Apple HIG: tertiary text 12-13pt */
            }

            .title-line {
                font-size: 1.75rem;
            }

            .hero-description {
                font-size: 16px;  /* Prevents iOS zoom on focus */
                line-height: 1.5;
            }

            .hero-cta {
                flex-direction: column;
                gap: 12px;  /* Apple HIG: 10px min between targets */
            }

            .cta-primary, .cta-secondary {
                width: 100%;
                justify-content: center;
                min-height: 50px;  /* Apple HIG: 44pt min + padding */
                font-size: 17px;   /* Apple HIG: primary action 17pt */
            }

            /* 2-column grid: halves the scroll depth (4 cards → 2 rows) */
            .feature-showcase {
                grid-template-columns: repeat(2, 1fr);
                gap: 10px;
            }

            .feature-card {
                padding: 16px 12px;  /* slightly more compact for 2-column */
            }

            .feature-card h3 {
                font-size: 15px;
            }

            .feature-card p {
                font-size: 13px;
                line-height: 1.4;
            }

            .topic-pills {
                gap: 10px;  /* Apple HIG: 10px min between touch targets */
            }

            .topic-pill {
                padding: 12px 20px;
                font-size: 15px;   /* Apple HIG: secondary text 15pt */
                min-height: 44px;  /* Apple HIG: 44pt touch target */
            }

            .section-title {
                font-size: 22px;  /* Apple HIG: section header scale */
            }
        }

        /* --- iPhone SE / Small iPhone (375x667 / 320x568) --- */
        @media (max-width: 430px) {
            .hero-welcome {
                padding: 70px 16px 20px;
            }

            .hero-content {
                padding: 20px 16px;
            }

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

            .hero-description {
                font-size: 16px;
            }

            .badge-text {
                font-size: 12px;  /* Apple HIG: minimum caption 12pt */
            }

            .feature-icon-wrap {
                width: 52px;
                height: 52px;
            }

            .feature-icon {
                font-size: 1.5rem;
            }
        }

        /* --- Apple Safe Area Insets (notch + home indicator) --- */
        @supports (padding: max(0px)) {
            .hero-welcome {
                padding-left: max(16px, env(safe-area-inset-left));
                padding-right: max(16px, env(safe-area-inset-right));
                padding-bottom: max(60px, calc(env(safe-area-inset-bottom) + 40px));
            }
        }

        /* --- iPad Multitasking (Split View / Slide Over) --- */
        @media (min-width: 320px) and (max-width: 504px) and (min-height: 600px) {
            .hero-welcome {
                padding: 70px 16px 20px;
            }

            .hero-content {
                padding: 20px 16px;
            }

            .title-line {
                font-size: 1.6rem;
            }

            .feature-showcase {
                grid-template-columns: repeat(2, 1fr);
                gap: 10px;
            }
        }

        /* --- Landscape phones (short height) --- */
        @media (max-height: 500px) and (orientation: landscape) {
            .hero-welcome {
                padding-top: 16px;
                padding-bottom: 16px;
            }

            .hero-content {
                padding: 20px;
            }

            .hero-badge {
                margin-bottom: 12px;
            }

            .hero-title {
                margin-bottom: 12px;
            }

            .title-line {
                font-size: 1.8rem;
            }

            .hero-description {
                margin-bottom: 16px;
            }

            .feature-showcase {
                grid-template-columns: repeat(4, 1fr);
                gap: 12px;
                margin-top: 20px;
            }

            .topics-preview {
                margin-top: 20px;
            }
        }

        /* --- Reduce Motion (Apple Accessibility) --- */
        @media (prefers-reduced-motion: reduce) {
            .hero-welcome,
            .feature-card,
            .hero-badge {
                animation: none;
            }

            .feature-card:hover {
                transform: none;
            }

            .topic-pill:hover {
                transform: none;
            }

            .cta-primary:hover,
            .cta-primary:active,
            .cta-secondary:hover {
                transform: none;
            }
        }

        /* --- Dark Mode Support (Apple HIG) --- */
        @media (prefers-color-scheme: dark) {
            .hero-content {
                background: linear-gradient(145deg, rgba(30,30,30,0.8) 0%, rgba(20,60,20,0.7) 100%);
                border-color: rgba(144,238,144,0.4);
            }

            .title-line {
                color: #f0f0f0;
                text-shadow: none;
            }

            .title-line.highlight {
                color: var(--primary-green);
            }

            .hero-description {
                color: rgba(255,255,255,0.7);
            }

            .feature-card {
                background: linear-gradient(145deg, rgba(40,40,40,0.75) 0%, rgba(30,50,30,0.65) 100%);
                border-color: rgba(144,238,144,0.3);
            }

            .feature-card h3 {
                color: #f0f0f0;
            }

            .feature-card p {
                color: rgba(255,255,255,0.6);
            }

            .topic-pill {
                background: linear-gradient(145deg, rgba(40,40,40,0.75) 0%, rgba(30,50,30,0.65) 100%);
                border-color: rgba(144,238,144,0.4);
                color: #f0f0f0;
            }

            .section-title {
                color: #f0f0f0;
                text-shadow: none;
            }

            .cta-secondary {
                color: var(--primary-green);
                border-color: var(--primary-green);
            }
        }

/* ================================
   Skip-to-Content Link (a11y)
================================ */
.skip-to-content {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
    z-index: 10000;
}

.skip-to-content:focus {
    position: fixed;
    top: 10px;
    left: 10px;
    width: auto;
    height: auto;
    padding: 12px 24px;
    background: var(--dark-green);
    color: white;
    font-family: 'Quicksand', sans-serif;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    text-decoration: none;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

/* ================================
   Reduced Motion (a11y)
================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ================================
   Accessibility: focus-visible styles
================================ */
a:focus-visible,
button:focus-visible,
select:focus-visible,
.menu-card:focus-visible,
.menu-item:focus-visible,
.topic-pill:focus-visible,
.feature-card:focus-visible,
.cta-primary:focus-visible,
.cta-secondary:focus-visible,
.auth-btn:focus-visible,
.topic-card:focus-visible,
.dropdown-item:focus-visible,
.bottom-menu-item:focus-visible,
.mobile-menu-toggle:focus-visible,
.settings-btn:focus-visible {
    outline: 3px solid var(--golden-yellow);
    outline-offset: 3px;
}

/* ================================
   Screen Reader Only
================================ */
.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;
}

/* ================================
   Settings Form
================================ */
.settings-form {
    padding: 1rem 1.5rem 1.5rem;
}

.settings-fieldset {
    border: 2px solid var(--accent-green);
    border-radius: 12px;
    padding: 14px 18px;
    margin-bottom: 14px;
}

.settings-fieldset legend {
    font-family: 'Fredoka', sans-serif;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--dark-green);
    padding: 0 8px;
}

.settings-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 0;
    cursor: pointer;
    font-size: 0.95rem;
    color: var(--text-dark);
}

.settings-toggle + .settings-toggle {
    border-top: 1px solid rgba(0, 0, 0, 0.06);
}

.settings-toggle input[type="checkbox"] {
    display: none;
}

.toggle-switch {
    width: 44px;
    height: 24px;
    background: #ccc;
    border-radius: 12px;
    position: relative;
    transition: background 0.3s;
    flex-shrink: 0;
}

.toggle-switch::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    top: 2px;
    left: 2px;
    transition: transform 0.3s;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.settings-toggle input:checked + .toggle-switch {
    background: var(--dark-green);
}

.settings-toggle input:checked + .toggle-switch::after {
    transform: translateX(20px);
}

.settings-range {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 0;
    font-size: 0.95rem;
    color: var(--text-dark);
    cursor: pointer;
}

.settings-range input[type="range"] {
    flex: 1;
    accent-color: var(--dark-green);
    height: 6px;
}

.range-value {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--dark-green);
    min-width: 36px;
    text-align: right;
}

/* ================================
   Dark Mode
================================ */
body.dark-mode {
    --primary-green: #1a3a1a;
    --dark-green: #66bb6a;
    --accent-green: #2d4a2d;
    --golden-yellow: #f0c040;
    --text-dark: #e0e0e0;
    --text-medium: #b0b0b0;
    background: linear-gradient(180deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: #e0e0e0;
}

body.dark-mode .sidebar {
    background: linear-gradient(180deg, #1a3a1a, #0d2b0d);
}

body.dark-mode .modal {
    background: #1e1e2e;
    border-color: #3a3a4a;
    color: #e0e0e0;
}

body.dark-mode .modal-header {
    border-bottom-color: #3a3a4a;
}

body.dark-mode .topic-card {
    background: #2d3748;
    border-color: #4a5568;
    color: #e0e0e0;
}

body.dark-mode .topic-card.completed {
    background: linear-gradient(135deg, #1a3a1a, #2d4a2d);
}

body.dark-mode .settings-fieldset {
    border-color: #3a5a3a;
}

body.dark-mode .form-group input,
body.dark-mode .form-group textarea {
    background: #2d3748;
    border-color: #4a5568;
    color: #e0e0e0;
}

/* ================================
   High Contrast Mode
================================ */
body.high-contrast {
    --text-dark: #000000;
    --text-medium: #333333;
    --dark-green: #005500;
    --golden-yellow: #cc8800;
}

body.high-contrast .topic-card,
body.high-contrast .modal,
body.high-contrast .sidebar {
    border-width: 3px;
}

/* ================================
   Reduced Motion (user setting)
================================ */
body.reduced-motion *,
body.reduced-motion *::before,
body.reduced-motion *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
}