:root {
            --bg-primary: #0b1224;
            --bg-secondary: #f8fafc;  
            --bg-glass: rgba(255, 255, 255, 0.95);
            --text-primary: #0f172a;
            --text-secondary: #475569;
            --accent: #3b82f6;
            --accent-hover: #2563eb;
            --border: #e2e8f0;
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --container-bg: linear-gradient(135deg, #f8fafc, #f1f5f9);
            --button-bg: #ffffff;
            --button-hover: #f8fafc;
            --display-bg: rgba(255, 255, 255, 0.98);
            --success: #059669;
            --error: #dc2626;
            --warning: #d97706;
            --info: #0284c7;

            /* Brand palette */
            --brand-navy: #002366;
            --brand-rose: #C08081;
            --brand-maroon: #701C1C;
            --brand-cream: #F0EAD6;
            --brand-blue: #1e40af;
            --brand-gold: #f59e0b;
            --brand-purple: #7c3aed;
            
            /* Enhanced gradients */
            --gradient-primary: linear-gradient(135deg, var(--brand-navy), var(--brand-blue), var(--brand-purple));
            --gradient-secondary: linear-gradient(135deg, var(--brand-rose), var(--brand-gold));
            --gradient-accent: linear-gradient(135deg, var(--brand-maroon), var(--brand-navy));
        }

        [data-theme="default"] {
            --bg-primary: var(--brand-cream);
            --bg-secondary: #fff7ef;
            --bg-glass: rgba(240, 234, 214, 0.85);
            --text-primary: #0b1224;
            --text-secondary: #4b5563;
            --accent: var(--brand-rose);
            --accent-hover: #a66a6b;
            --border: rgba(0, 35, 102, 0.15);
            --shadow: 0 8px 24px rgba(0, 35, 102, 0.12);
            --container-bg: linear-gradient(135deg, var(--brand-cream), #ffffff);
            --button-bg: #ffffff;
            --button-hover: #f7f3e8;
            --display-bg: rgba(255, 255, 255, 0.96);
            --success: #0f766e;
            --error: var(--brand-maroon);
            --warning: #b45309;
            --info: var(--brand-navy);
        }

        [data-theme="dark"] {
            --bg-primary: #0b1224;
            --bg-secondary: #1e293b;
            --bg-glass: rgba(15, 23, 42, 0.95);
            --text-primary: #f1f5f9;
            --text-secondary: #cbd5e1;
            --accent: #3b82f6;
            --accent-hover: #2563eb;
            --border: rgba(148, 163, 184, 0.2);
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
            --container-bg: linear-gradient(135deg, #1e293b, #0f172a);
            --button-bg: rgba(30, 41, 59, 0.8);
            --button-hover: rgba(51, 65, 85, 0.9);
            --display-bg: rgba(15, 23, 42, 0.98);
            --success: #10b981;
            --error: #ef4444;
            --warning: #f59e0b;
            --info: #06b6d4;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            -webkit-tap-highlight-color: transparent;
            -webkit-touch-callout: none;
        }

        *:not(.no-transition) {
            transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
            background: var(--bg-primary);
            color: var(--text-primary);
            min-height: 100vh;
            min-height: -webkit-fill-available;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: env(safe-area-inset-top, 20px) env(safe-area-inset-right, 20px) env(safe-area-inset-bottom, 20px) env(safe-area-inset-left, 20px);
            position: relative;
            overflow-x: hidden;
            -webkit-overflow-scrolling: touch;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            text-rendering: optimizeLegibility;
        }

        /* Device-specific optimizations */
        @media (max-width: 768px) {
            body {
                -webkit-text-size-adjust: 100%;
                -ms-text-size-adjust: 100%;
            }

        /* TikTok-style Preview Component */
        .tiktok-preview {
            background: var(--bg-glass);
            border-radius: 20px;
            padding: 20px;
            backdrop-filter: blur(20px);
            border: 1px solid var(--glass-border);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            animation: slideUp 0.6s ease-out;
        }

        .video-container {
            position: relative;
            margin-bottom: 20px;
        }

        .video-thumbnail {
            width: 100%;
            height: 400px;
            background-size: cover;
            background-position: center;
            border-radius: 16px;
            position: relative;
            overflow: hidden;
            cursor: pointer;
            transition: transform 0.3s ease;
        }

        .video-thumbnail:hover {
            transform: scale(1.02);
        }

        .play-overlay {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.3);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
        }

        .play-overlay:hover {
            background: rgba(0, 0, 0, 0.5);
        }

        .play-button {
            width: 80px;
            height: 80px;
            background: rgba(255, 255, 255, 0.9);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
            backdrop-filter: blur(10px);
        }

        .play-button:hover {
            transform: scale(1.1);
            background: rgba(255, 255, 255, 1);
        }

        .video-stats {
            position: absolute;
            bottom: 15px;
            right: 15px;
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        .stat-item {
            display: flex;
            align-items: center;
            gap: 8px;
            background: rgba(0, 0, 0, 0.7);
            padding: 8px 12px;
            border-radius: 20px;
            color: white;
            font-size: 14px;
            font-weight: 600;
            backdrop-filter: blur(10px);
        }

        .video-info {
            display: flex;
            flex-direction: column;
            gap: 20px;
        }

        .author-info {
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .author-avatar {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            object-fit: cover;
            border: 3px solid var(--brand-rose);
        }

        .author-name {
            font-size: 18px;
            font-weight: 700;
            color: var(--text-primary);
            margin: 0;
        }

        .video-views {
            font-size: 14px;
            color: var(--text-secondary);
            margin: 0;
        }

        .quality-options {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
        }

        .quality-btn {
            background: var(--bg-secondary);
            border: 2px solid var(--border-color);
            border-radius: 12px;
            padding: 12px 16px;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 4px;
            min-width: 120px;
        }

        .quality-btn:hover {
            border-color: var(--brand-rose);
            transform: translateY(-2px);
        }

        .quality-btn.active {
            background: var(--gradient-accent);
            border-color: var(--brand-navy);
            color: white;
        }

        .quality-label {
            font-size: 14px;
            font-weight: 600;
        }

        .quality-badge {
            font-size: 12px;
            padding: 2px 8px;
            border-radius: 8px;
            background: var(--brand-gold);
            color: white;
            font-weight: 500;
        }

        .quality-btn.active .quality-badge {
            background: rgba(255, 255, 255, 0.2);
        }

        /* Video Modal */
        .video-modal {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.8);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 1000;
            backdrop-filter: blur(10px);
        }

        .modal-content {
            background: var(--bg-glass);
            border-radius: 20px;
            padding: 30px;
            max-width: 500px;
            width: 90%;
            backdrop-filter: blur(20px);
            border: 1px solid var(--glass-border);
        }

        .modal-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 20px;
        }

        .modal-header h3 {
            margin: 0;
            color: var(--text-primary);
        }

        .close-modal {
            background: none;
            border: none;
            font-size: 24px;
            cursor: pointer;
            color: var(--text-secondary);
            padding: 5px;
        }

        .preview-placeholder {
            text-align: center;
        }

        .preview-placeholder img {
            width: 100%;
            max-width: 300px;
            border-radius: 12px;
            margin-bottom: 20px;
        }

        .preview-message h4 {
            color: var(--text-primary);
            margin-bottom: 10px;
        }

        .preview-message p {
            color: var(--text-secondary);
            margin: 0;
        }

        /* Mobile Responsive for TikTok Preview */
        @media (max-width: 768px) {
            .video-thumbnail {
                height: 300px;
            }
            
            .quality-options {
                flex-direction: column;
            }
            
            .quality-btn {
                min-width: 100%;
            }
            
            .video-stats {
                bottom: 10px;
                right: 10px;
                gap: 10px;
            }
            
            .stat-item {
                padding: 6px 10px;
                font-size: 12px;
            }
        }
        }

        /* iPhone-specific styles */
        @media screen and (-webkit-min-device-pixel-ratio: 2) and (max-width: 768px) {
            .container {
                backdrop-filter: blur(20px);
                background: rgba(255, 255, 255, 0.95);
                border: 1px solid rgba(255, 255, 255, 0.2);
            }
            
            [data-theme="dark"] .container {
                background: rgba(15, 23, 42, 0.95);
                border: 1px solid rgba(148, 163, 184, 0.1);
            }
            
            .download-btn {
                background: linear-gradient(135deg, #3b82f6, #1d4ed8);
                box-shadow: 0 8px 25px rgba(59, 130, 246, 0.3);
            }
            
            .feature-card {
                backdrop-filter: blur(15px);
                background: rgba(255, 255, 255, 0.8);
                border: 1px solid rgba(255, 255, 255, 0.2);
            }
        }

        /* Android-specific styles */
        @media screen and (max-width: 768px) and (min-resolution: 1.5dppx) {
            .container {
                background: linear-gradient(135deg, #f8fafc, #e2e8f0);
                box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            }
            
            [data-theme="dark"] .container {
                background: linear-gradient(135deg, #0f172a, #1e293b);
                box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
            }
            
            .download-btn {
                background: linear-gradient(135deg, #3b82f6, #2563eb);
                box-shadow: 0 10px 30px rgba(59, 130, 246, 0.4);
            }
        }

        /* Desktop-specific styles */
        @media (min-width: 1024px) {
            .container {
                max-width: 600px;
                backdrop-filter: blur(25px);
                background: rgba(255, 255, 255, 0.9);
                border: 1px solid rgba(255, 255, 255, 0.3);
                box-shadow: 0 25px 50px rgba(0, 0, 0, 0.1);
            }
            
            [data-theme="dark"] .container {
                background: rgba(15, 23, 42, 0.9);
                border: 1px solid rgba(148, 163, 184, 0.2);
                box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4);
            }
            
            .download-btn {
                background: linear-gradient(135deg, #3b82f6, #1e40af);
                box-shadow: 0 15px 35px rgba(59, 130, 246, 0.3);
                transition: all 0.3s ease;
            }
            
            .download-btn:hover {
                transform: translateY(-3px);
                box-shadow: 0 20px 40px rgba(59, 130, 246, 0.4);
            }
            
            .feature-card {
                backdrop-filter: blur(20px);
                background: rgba(255, 255, 255, 0.7);
                border: 1px solid rgba(255, 255, 255, 0.3);
                transition: all 0.3s ease;
            }
            
            .feature-card:hover {
                transform: translateY(-8px);
                box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            }
        }

        /* High DPI display optimizations */
        @media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
            .logo-icon img,
            .recent-thumbnail img {
                image-rendering: -webkit-optimize-contrast;
                image-rendering: crisp-edges;
            }
        }

        .orb {
            position: fixed;
            width: 40vmax;
            height: 40vmax;
            border-radius: 50%;
            mix-blend-mode: screen;
            filter: blur(40px);
            opacity: 0.15;
            z-index: -1;
            will-change: transform;
            transform: translateZ(0);
        }

        /* Reduce animations on low-end devices */
        @media (prefers-reduced-motion: reduce) {
            .orb {
                animation: none;
            }
            .feature-card,
            .step {
                animation: none;
            }
        }

        .orb.one {
            top: -10vmax;
            left: -10vmax;
            background: radial-gradient(circle, var(--brand-navy), transparent 60%);
        }

        .orb.two {
            bottom: -12vmax;
            right: -8vmax;
            background: radial-gradient(circle, var(--brand-rose), transparent 60%);
        }

        .header {
            width: 100%;
            max-width: 500px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 30px;
            padding: 20px 0;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 24px;
        }

        .logo-icon {
            width: 40px;
            height: 40px;
            border-radius: 10px;
            overflow: hidden;
            display: flex;
            align-items: center;
            justify-content: center;
            border: 2px solid var(--accent);
            background: var(--bg-glass);
            position: relative;
        }

        .logo-icon img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            object-position: center;
            display: block;
        }

        .theme-toggle {
            width: 36px;
            height: 36px;
            background: rgba(255, 255, 255, 0.08);
            border-radius: 50%;
            position: relative;
            cursor: pointer;
            border: 1px solid rgba(255, 255, 255, 0.15);
            outline: none;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            color: var(--text-primary);
        }

        .theme-toggle::after {
            display: none;
        }

        .container {
            background: var(--container-bg);
            border-radius: 20px;
            padding: 25px;
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            backdrop-filter: blur(10px);
            max-width: 500px;
            width: 100%;
            animation: slideUp 0.6s ease-out;
        }

        .title {
            font-size: clamp(2.5rem, 8vw, 4rem);
            font-weight: 800;
            background: var(--gradient-primary);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            text-align: center;
            margin-bottom: 1rem;
            letter-spacing: -0.02em;
            line-height: 1.1;
            animation: titleGlow 3s ease-in-out infinite;
        }

        @keyframes titleGlow {
            0% { filter: drop-shadow(0 0 10px rgba(30, 64, 175, 0.3)); }
            100% { filter: drop-shadow(0 0 20px rgba(124, 58, 237, 0.5)); }
        }

        .subtitle {
            text-align: center;
            margin-bottom: 25px;
            font-size: 16px;
            color: var(--text-secondary);
            line-height: 1.5;
        }

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

        .input-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: var(--text-secondary);
        }

        .input-container {
            position: relative;
            display: flex;
            align-items: center;
        }

        .url-input {
            width: 100%;
            padding: 15px 95px 15px 15px;
            border-radius: 12px;
            border: 1px solid var(--border);
            background: var(--display-bg);
            font-size: 16px;
            color: var(--text-primary);
            outline: none;
            transition: all 0.2s ease;
            -webkit-appearance: none;
            appearance: none;
            -webkit-border-radius: 12px;
        }

        .clear-btn {
            position: absolute;
            right: 15px;
            top: 50%;
            transform: translateY(-50%);
            width: 30px;
            height: 30px;
            border: none;
            background: var(--text-secondary);
            color: white;
            border-radius: 50%;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 12px;
            opacity: 0;
            visibility: hidden;
            transition: all 0.2s ease;
            z-index: 10;
        }

        .clear-btn:hover {
            background: var(--error);
            transform: translateY(-50%) scale(1.1);
        }

        .clear-btn.visible {
            opacity: 1;
            visibility: visible;
        }

        .paste-btn {
            position: absolute;
            right: 55px;
            top: 50%;
            transform: translateY(-50%);
            width: 30px;
            height: 30px;
            border: none;
            background: var(--accent);
            color: white;
            border-radius: 50%;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 12px;
            transition: all 0.2s ease;
            z-index: 10;
        }

        .paste-btn:hover {
            transform: translateY(-50%) scale(1.05);
            filter: brightness(1.1);
        }

        .url-input:focus {
            border-color: var(--accent);
            box-shadow: 0 0 0 3px rgba(74, 124, 255, 0.1);
        }

        .input-help {
            display: flex;
            align-items: center;
            gap: 8px;
            margin-top: 8px;
            font-size: 14px;
            color: var(--text-secondary);
            background: var(--bg-glass);
            padding: 8px 12px;
            border-radius: 8px;
            border: 1px solid var(--border);
        }

        .input-help i {
            color: var(--accent);
            font-size: 12px;
        }

        /* Optimized Animations */
        .container {
            animation: slideUp 0.4s ease-out;
        }

        .feature-card {
            animation: fadeInUp 0.4s ease-out;
            will-change: transform, opacity;
        }

        .feature-card:nth-child(1) { animation-delay: 0.05s; }
        .feature-card:nth-child(2) { animation-delay: 0.1s; }
        .feature-card:nth-child(3) { animation-delay: 0.15s; }
        .feature-card:nth-child(4) { animation-delay: 0.2s; }
        .feature-card:nth-child(5) { animation-delay: 0.25s; }
        .feature-card:nth-child(6) { animation-delay: 0.3s; }

        .step {
            animation: fadeInLeft 0.4s ease-out;
            will-change: transform, opacity;
        }

        .step:nth-child(1) { animation-delay: 0.05s; }
        .step:nth-child(2) { animation-delay: 0.1s; }
        .step:nth-child(3) { animation-delay: 0.15s; }

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

        @keyframes fadeInLeft {
            from {
                opacity: 0;
                transform: translateX(-30px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        /* Hover Effects */
        .download-btn:hover {
            background: linear-gradient(135deg, #3b6de0, #e63e6d);
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(74, 124, 255, 0.3);
        }

        .option-btn:hover {
            background: var(--button-hover);
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        }

        .contact-link:hover {
            color: var(--accent);
            transform: translateX(5px);
        }

        /* Loading Animation */
        .loading {
            animation: pulse 2s ease-in-out infinite;
        }

        /* Success Animation */
        .success-message {
            animation: bounceIn 0.5s ease-out;
        }

        @keyframes bounceIn {
            0% {
                opacity: 0;
                transform: scale(0.3);
            }
            50% {
                opacity: 1;
                transform: scale(1.05);
            }
            70% {
                transform: scale(0.9);
            }
            100% {
                opacity: 1;
                transform: scale(1);
            }
        }

        .download-btn {
            width: 100%;
            padding: 16px 32px;
            border-radius: 16px;
            border: none;
            background: var(--gradient-primary);
            color: white;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            transition: all 0.3s ease;
            box-shadow: 0 8px 25px rgba(0, 35, 102, 0.3);
            position: relative;
            overflow: hidden;
            backdrop-filter: blur(10px);
        }

        .download-btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
            transition: left 0.5s;
        }

        .download-btn:hover::before {
            left: 100%;
        }

        .download-btn:hover {
            background: var(--gradient-secondary);
            transform: translateY(-3px) scale(1.02);
            box-shadow: 0 12px 35px rgba(124, 58, 237, 0.4);
        }

        .download-btn:active {
            transform: translateY(0);
        }

        .download-btn:disabled {
            background: var(--text-secondary);
            cursor: not-allowed;
            transform: none;
        }

        .result {
            margin-top: 25px;
            display: none;
        }

        .video-preview {
            width: 100%;
            border-radius: 12px;
            overflow: hidden;
            margin-bottom: 15px;
            border: 1px solid var(--border);
            background: var(--display-bg);
        }

        .video-preview video {
            width: 100%;
            display: block;
        }

        .loading {
            display: none;
            text-align: center;
            padding: 20px;
            color: var(--text-secondary);
        }

        .spinner {
            width: 40px;
            height: 40px;
            border: 4px solid rgba(74, 124, 255, 0.2);
            border-left: 4px solid var(--accent);
            border-radius: 50%;
            animation: spin 1s linear infinite;
            margin: 0 auto 15px;
        }

        .error-message {
            display: none;
            padding: 15px;
            background: rgba(239, 68, 68, 0.1);
            border: 1px solid var(--error);
            border-radius: 12px;
            color: var(--error);
            margin-top: 15px;
        }

        .success-message {
            display: none;
            padding: 15px;
            background: rgba(16, 185, 129, 0.1);
            border: 1px solid var(--success);
            border-radius: 12px;
            color: var(--success);
            margin-top: 15px;
        }

        /* Visitor Info */
        .visitor-info {
            position: fixed;
            top: 20px;
            left: 20px;
            background: var(--bg-glass);
            padding: 8px 15px;
            border-radius: 20px;
            border: 1px solid var(--border);
            backdrop-filter: blur(10px);
            font-size: 14px;
            color: var(--text-secondary);
            animation: slideIn 0.5s ease;
            z-index: 100;
        }

        .visitor-count {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .visitor-count i {
            color: var(--accent);
        }

        /* Recent Downloads */
        .recent-downloads {
            background: var(--bg-glass);
            border-radius: 12px;
            border: 1px solid var(--border);
            margin: 20px 0;
            overflow: hidden;
        }

        .recent-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px;
            border-bottom: 1px solid var(--border);
        }

        .recent-header h3 {
            font-size: 16px;
            color: var(--text-primary);
        }

        .download-count {
            display: flex;
            align-items: center;
            gap: 8px;
            color: var(--accent);
            font-weight: 600;
        }

        .recent-list {
            max-height: 200px;
            overflow-y: auto;
            padding: 10px;
        }

        .recent-item {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px;
            border-radius: 8px;
            transition: all 0.2s ease;
        }

        .recent-item:hover {
            background: var(--bg-secondary);
        }

        .recent-thumbnail {
            width: 40px;
            height: 40px;
            border-radius: 8px;
            overflow: hidden;
        }

        .recent-thumbnail img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        /* Video Actions */
        .video-actions {
            display: flex;
            flex-direction: column;
            gap: 15px;
            margin-top: 15px;
        }

        .quality-selector {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px;
            background: var(--bg-glass);
            border-radius: 12px;
            border: 1px solid var(--border);
        }

        .quality-selector select {
            flex: 1;
            padding: 8px;
            border-radius: 8px;
            border: 1px solid var(--border);
            background: var(--bg-primary);
            color: var(--text-primary);
            outline: none;
            -webkit-appearance: none;
            appearance: none;
        }

        .download-options {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 12px;
        }



        @keyframes slideIn {
            from { transform: translateX(-100%); opacity: 0; }
            to { transform: translateX(0); opacity: 1; }
        }

        @keyframes scaleIn {
            from { transform: scale(0.8); opacity: 0; }
            to { transform: scale(1); opacity: 1; }
        }

        .option-btn {
            padding: 12px;
            border-radius: 12px;
            border: none;
            background: var(--button-bg);
            border: 1px solid var(--border);
            color: var(--text-primary);
            font-weight: 600;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            transition: all 0.2s ease;
        }

        .option-btn:hover {
            background: var(--button-hover);
            transform: translateY(-2px);
        }

        .option-btn:active {
            transform: translateY(0);
        }

        .option-btn.primary {
            background: var(--accent);
            color: white;
            border: none;
        }

        .option-btn.primary:hover {
            background: var(--accent-hover);
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }

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

        /* Battery Status */
        .battery-status {
            position: fixed;
            top: 20px;
            right: 20px;
            display: flex;
            align-items: center;
            gap: 8px;
            background: var(--bg-glass);
            padding: 8px 12px;
            border-radius: 20px;
            border: 1px solid var(--border);
            backdrop-filter: blur(10px);
            font-size: 14px;
            color: var(--text-secondary);
            transition: all 0.3s ease;
        }

        .battery-icon {
            width: 24px;
            height: 12px;
            border: 2px solid currentColor;
            border-radius: 3px;
            padding: 1px;
            position: relative;
        }

        .battery-icon::after {
            content: '';
            position: absolute;
            width: 3px;
            height: 6px;
            background: currentColor;
            right: -5px;
            top: 50%;
            transform: translateY(-50%);
            border-radius: 0 2px 2px 0;
        }

        .battery-level {
            height: 100%;
            width: 0%;
            background: currentColor;
            border-radius: 1px;
            transition: all 0.3s ease;
        }

        .battery-charging {
            position: absolute;
            inset: 0;
            display: none;
            align-items: center;
            justify-content: center;
            color: var(--success);
        }

        .battery-charging i {
            font-size: 8px;
        }

        .battery-status.charging {
            color: var(--success);
        }

        .battery-status.charging .battery-charging {
            display: flex;
        }

        .battery-status.low {
            color: var(--error);
        }

        /* Features Section */
        .features {
            max-width: 800px;
            width: 100%;
            margin: 40px auto;
            padding: 0 20px;
        }

        .features h2 {
            text-align: center;
            margin-bottom: 30px;
            font-size: 28px;
            background: linear-gradient(90deg, #4a7cff, #ff4d7d);
            background-clip: text;
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            animation: slideUp 0.6s ease-out;
        }

        .feature-card {
            background: var(--bg-glass);
            border: 1px solid var(--border);
            border-radius: 15px;
            padding: 20px;
            text-align: center;
            backdrop-filter: blur(10px);
            transition: all 0.3s ease;
        }

        .feature-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow);
        }

        .feature-icon {
            width: 50px;
            height: 50px;
            margin: 0 auto 15px;
            background: var(--accent);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            color: white;
        }

        .feature-card div:not(.feature-icon) {
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--text-primary);
        }

        .feature-card p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.5;
        }

        /* How to Use Section */
        .how-to-use {
            max-width: 800px;
            width: 100%;
            margin: 40px auto;
            padding: 0 20px;
        }

        .how-to-use h2 {
            text-align: center;
            margin-bottom: 30px;
            font-size: 28px;
            background: linear-gradient(90deg, #4a7cff, #ff4d7d);
            background-clip: text;
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .steps-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 30px;
            margin-top: 30px;
        }

        .step {
            display: flex;
            align-items: flex-start;
            gap: 20px;
            padding: 25px;
            background: var(--bg-glass);
            border: 1px solid var(--border);
            border-radius: 15px;
            backdrop-filter: blur(10px);
            transition: all 0.3s ease;
        }

        .step:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow);
        }

        .step-number {
            width: 40px;
            height: 40px;
            background: var(--accent);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 18px;
            flex-shrink: 0;
        }

        .step-content h3 {
            margin-bottom: 10px;
            color: var(--text-primary);
            font-size: 18px;
        }

        .step-content p {
            color: var(--text-secondary);
            line-height: 1.6;
            margin-bottom: 15px;
        }

        .step-visual {
            width: 50px;
            height: 50px;
            background: var(--accent);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 20px;
        }

        /* API Documentation */
        .api-docs {
            max-width: 800px;
            width: 100%;
            margin: 40px auto;
            padding: 0 20px;
        }

        .api-docs h2 {
            text-align: center;
            margin-bottom: 30px;
            font-size: 28px;
            background: linear-gradient(90deg, #4a7cff, #ff4d7d);
            background-clip: text;
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .api-container {
            background: var(--bg-glass);
            border: 1px solid var(--border);
            border-radius: 15px;
            padding: 30px;
            backdrop-filter: blur(10px);
        }

        .api-info h3 {
            color: var(--text-primary);
            margin-bottom: 15px;
            font-size: 24px;
        }

        .api-info p {
            color: var(--text-secondary);
            margin-bottom: 20px;
            line-height: 1.6;
        }

        .api-endpoint, .api-params, .api-example, .api-response {
            margin-bottom: 20px;
            padding: 15px;
            background: var(--bg-primary);
            border: 1px solid var(--border);
            border-radius: 8px;
        }

        .api-endpoint strong, .api-params strong, .api-example strong, .api-response strong {
            color: var(--text-primary);
            display: block;
            margin-bottom: 10px;
        }

        .api-endpoint code {
            background: var(--accent);
            color: white;
            padding: 4px 8px;
            border-radius: 4px;
            font-family: 'Courier New', monospace;
        }

        .api-params ul {
            margin: 10px 0;
            padding-left: 20px;
        }

        .api-params li {
            margin-bottom: 5px;
            color: var(--text-secondary);
        }

        .api-params code {
            background: var(--bg-secondary);
            padding: 2px 6px;
            border-radius: 4px;
            font-family: 'Courier New', monospace;
        }

        .api-example pre, .api-response pre {
            background: var(--bg-secondary);
            padding: 15px;
            border-radius: 8px;
            overflow-x: auto;
            margin: 10px 0;
        }

        .api-example code, .api-response code {
            font-family: 'Courier New', monospace;
            font-size: 14px;
            line-height: 1.4;
        }

        /* Enhanced Documentation Styles */
        .doc-section {
            margin: 25px 0;
            padding: 20px;
            background: var(--bg-primary);
            border-radius: 10px;
            border-left: 4px solid var(--accent);
            border: 1px solid var(--border);
        }

        .doc-section h4 {
            color: var(--text-primary);
            margin-bottom: 15px;
            font-size: 18px;
            font-weight: 600;
        }

        .doc-list {
            margin: 15px 0;
            padding-left: 25px;
        }

        .doc-list li {
            margin: 10px 0;
            color: var(--text-secondary);
            line-height: 1.6;
        }

        .doc-list code {
            background: var(--accent);
            color: white;
            padding: 2px 6px;
            border-radius: 4px;
            font-family: 'Courier New', monospace;
            font-size: 0.9em;
        }

        .faq-item {
            margin: 25px 0;
            padding: 20px;
            background: var(--bg-primary);
            border-radius: 10px;
            border-left: 4px solid var(--accent);
            border: 1px solid var(--border);
        }

        .faq-item h4 {
            color: var(--accent);
            margin-bottom: 10px;
            font-size: 16px;
            font-weight: 600;
        }

        .faq-item p {
            color: var(--text-secondary);
            line-height: 1.6;
            margin: 0;
        }

        .api-container {
            margin-bottom: 30px;
            padding-bottom: 30px;
            border-bottom: 1px solid var(--border);
        }

        .api-container:last-child {
            border-bottom: none;
            padding-bottom: 0;
        }

        /* Footer */
        .footer {
            width: 100%;
            padding: 40px 20px 20px;
            color: var(--text-secondary);
            margin-top: auto;
            background: var(--bg-glass);
            border-top: 1px solid var(--border);
        }

        .footer-content {
            max-width: 1000px;
            margin: 0 auto;
        }

        .footer-main {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            margin-bottom: 30px;
        }

        .footer-brand h3 {
            color: var(--text-primary);
            margin-bottom: 10px;
            font-size: 20px;
        }

        .footer-brand p {
            color: var(--text-secondary);
            line-height: 1.6;
        }

        .footer-links {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
        }

        .link-group h4 {
            color: var(--text-primary);
            margin-bottom: 15px;
            font-size: 16px;
        }

        .contact-link {
            display: flex;
            align-items: center;
            gap: 10px;
            color: var(--text-secondary);
            text-decoration: none;
            margin-bottom: 10px;
            transition: all 0.2s ease;
        }

        .contact-link:hover {
            color: var(--accent);
            transform: translateX(5px);
        }

        .contact-link i {
            width: 20px;
            text-align: center;
        }

        .footer-bottom {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding-top: 20px;
            border-top: 1px solid var(--border);
            flex-wrap: wrap;
            gap: 20px;
        }

        .footer-stats {
            display: flex;
            gap: 20px;
            font-size: 14px;
        }

        .stat {
            display: flex;
            align-items: center;
            gap: 5px;
        }

        .stat i {
            color: var(--accent);
        }

        .footer-credit {
            color: var(--text-secondary);
            font-size: 14px;
        }

        .footer i.fa-heart {
            color: var(--accent);
            animation: pulse 1.5s ease infinite;
        }

        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.2); }
            100% { transform: scale(1); }
        }

        @media (max-width: 480px) {
            body {
                padding: 10px;
            }
            .container { 
                padding: 15px;
                margin: 0 auto;
            }
            .header { 
                padding: 10px 0;
                max-width: 100%;
            }
            .logo { 
                font-size: 18px;
                gap: 8px;
            }
            .logo-icon { 
                width: 32px; 
                height: 32px; 
            }
            .battery-status { 
                top: auto;
                bottom: 20px;
                right: 20px;
                font-size: 12px;
                padding: 6px 10px;
            }
            .features-grid {
                grid-template-columns: 1fr;
                gap: 15px;
            }
            .visitor-info {
                position: static;
                margin-bottom: 15px;
                width: 100%;
                max-width: 500px;
            }
            .title {
                font-size: 20px;
            }
            .subtitle {
                font-size: 14px;
            }
            .input-group {
                margin-bottom: 15px;
            }
            .url-input {
                padding: 12px;
                font-size: 14px;
            }
            .download-btn {
                padding: 12px;
                font-size: 14px;
            }
            .features {
                margin: 20px auto;
            }
            .features h2 {
                font-size: 24px;
                margin-bottom: 20px;
            }
            .feature-card {
                padding: 15px;
            }
            .feature-icon {
                width: 40px;
                height: 40px;
                font-size: 20px;
            }
            .feature-card p {
                font-size: 13px;
            }
            .quality-selector {
                flex-direction: column;
                align-items: flex-start;
                gap: 8px;
            }
            .quality-selector label {
                margin-bottom: 4px;
            }
            .quality-selector select {
                width: 100%;
            }
            .download-options {
                grid-template-columns: 1fr;
            }
            .option-btn {
                padding: 10px;
                font-size: 14px;
            }
            .footer {
                padding: 15px;
                margin-top: 20px;
            }
            .footer-content {
                font-size: 13px;
            }
            .footer-stats {
                flex-direction: column;
                gap: 10px;
                align-items: center;
            }
            .footer-main {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .footer-links {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
            .how-to-use h2, .api-docs h2 {
                font-size: 24px;
            }
            .steps-container {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .step {
                flex-direction: column;
                text-align: center;
                gap: 15px;
            }
            .step-number {
                align-self: center;
            }
            .api-container {
                padding: 20px;
            }
            .api-example pre, .api-response pre {
                font-size: 12px;
                padding: 10px;
            }
        }

        @media (max-width: 360px) {
            .visitor-count {
                flex-wrap: wrap;
                justify-content: center;
            }
            .logo {
                font-size: 16px;
            }
            .logo-icon {
                width: 28px;
                height: 28px;
            }
            .feature-card {
                padding: 12px;
            }
        }

        @supports (-webkit-touch-callout: none) {
            body {
                min-height: -webkit-fill-available;
            }
            .battery-status {
                padding-bottom: env(safe-area-inset-bottom, 20px);
                padding-right: env(safe-area-inset-right, 20px);
            }
            .video-preview {
                width: 100%;
                border-radius: 12px;
                -webkit-border-radius: 12px;
            }
            .download-btn:active,
            .option-btn:active {
                transform: scale(0.98);
            }
            .quality-selector select {
                background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
                background-repeat: no-repeat;
                background-position: right 8px center;
                background-size: 16px;
                padding-right: 32px;
            }
            .url-input {
                padding: 15px;
                line-height: 1.3;
            }
            @supports (padding: max(0px)) {
                .container {
                    padding-left: max(15px, env(safe-area-inset-left));
                    padding-right: max(15px, env(safe-area-inset-right));
                }
                .battery-status {
                    padding-right: max(12px, env(safe-area-inset-right));
                    padding-bottom: max(20px, env(safe-area-inset-bottom));
                }
            }
        }