:root {
            --primary: #ff6b6b;
            --primary-dark: #e55a5a;
            --secondary: #4ecdc4;
            --success: #1dd1a1;
            --warning: #feca57;
            --dark: #222f3e;
            --light: #f8f9fa;
            --gray: #6c757d;
            --light-gray: #e9ecef;
            --border-radius: 12px;
            --shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
            --premium-gradient: linear-gradient(135deg, #ff6b6b, #ff9ff3);
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', system-ui, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
            color: var(--dark);
            line-height: 1.6;
            min-height: 100vh;
            padding: 20px;
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
        }
        
        /* Premium Header */
        .premium-header {
            background: linear-gradient(135deg, #222f3e 0%, #1a252f 100%);
            color: white;
            padding: 30px;
            border-radius: var(--border-radius);
            margin-bottom: 30px;
            box-shadow: var(--shadow);
            position: relative;
            overflow: hidden;
        }
        
        .premium-header::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: var(--premium-gradient);
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 20px;
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 15px;
        }
        
        .logo-icon {
            background: var(--premium-gradient);
            width: 50px;
            height: 50px;
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
        }
        
        .logo-text h1 {
            font-size: 2.2rem;
            font-weight: 800;
            background: var(--premium-gradient);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        
        .premium-tag {
            background: var(--premium-gradient);
            padding: 6px 16px;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 700;
            display: inline-block;
            margin-top: 5px;
        }
        
        /* Main Layout */
        .main-layout {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
            margin-bottom: 40px;
        }
        
        @media (max-width: 1024px) {
            .main-layout {
                grid-template-columns: 1fr;
            }
        }
        
        /* Premium Cards */
        .premium-card {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            padding: 30px;
            transition: all 0.3s ease;
            border: 1px solid rgba(0, 0, 0, 0.05);
            height: fit-content;
        }
        
        .card-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 25px;
            padding-bottom: 15px;
            border-bottom: 2px solid var(--light-gray);
        }
        
        .card-title {
            display: flex;
            align-items: center;
            gap: 12px;
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--dark);
        }
        
        .card-title i {
            color: var(--primary);
            font-size: 1.3rem;
        }
        
        /* Upload Area */
        .upload-area {
            border: 3px dashed var(--light-gray);
            border-radius: var(--border-radius);
            padding: 50px 30px;
            text-align: center;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-bottom: 25px;
            position: relative;
            background: white;
        }
        
        .upload-area:hover {
            border-color: var(--primary);
            background: rgba(255, 107, 107, 0.02);
        }
        
        .upload-area.dragover {
            border-color: var(--primary);
            background: rgba(255, 107, 107, 0.05);
            transform: scale(1.01);
        }
        
        .upload-icon {
            font-size: 3rem;
            color: var(--primary);
            margin-bottom: 20px;
        }
        
        .supported-formats {
            display: flex;
            justify-content: center;
            gap: 15px;
            margin-top: 20px;
            flex-wrap: wrap;
        }
        
        .format-badge {
            padding: 6px 15px;
            background: var(--light-gray);
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--dark);
        }
        
        .format-badge.webp {
            background: rgba(30, 144, 255, 0.1);
            color: #1e90ff;
            border: 1px solid rgba(30, 144, 255, 0.2);
        }
        
        /* Conversion Settings */
        .settings-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 20px;
            margin-bottom: 25px;
        }
        
        @media (max-width: 768px) {
            .settings-grid {
                grid-template-columns: 1fr;
            }
        }
        
        .setting-item {
            margin-bottom: 15px;
        }
        
        .setting-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: var(--dark);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .setting-label i {
            color: var(--primary);
        }
        
        /* Range Sliders */
        .range-slider {
            width: 100%;
            height: 8px;
            -webkit-appearance: none;
            background: var(--light-gray);
            border-radius: 4px;
            outline: none;
        }
        
        .range-slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 20px;
            height: 20px;
            background: var(--primary);
            border-radius: 50%;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 3px solid white;
            box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
        }
        
        .range-slider::-webkit-slider-thumb:hover {
            background: var(--primary-dark);
            transform: scale(1.2);
        }
        
        /* Premium Buttons */
        .premium-btn {
            background: var(--premium-gradient);
            color: white;
            border: none;
            padding: 16px 28px;
            border-radius: var(--border-radius);
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            white-space: nowrap;
        }
        
        .premium-btn:hover:not(:disabled) {
            transform: translateY(-2px);
            box-shadow: 0 8px 20px rgba(255, 107, 107, 0.3);
        }
        
        .premium-btn:disabled {
            opacity: 0.6;
            cursor: not-allowed;
        }
        
        .premium-btn-success {
            background: linear-gradient(135deg, var(--success), #1aa87e);
        }
        
        .premium-btn-danger {
            background: linear-gradient(135deg, var(--primary), #e55a5a);
        }
        
        .premium-btn-warning {
            background: linear-gradient(135deg, var(--warning), #e6b400);
        }
        
        /* Stats Grid */
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 15px;
            margin-bottom: 25px;
        }
        
        @media (max-width: 480px) {
            .stats-grid {
                grid-template-columns: 1fr;
            }
        }
        
        .stat-card {
            background: linear-gradient(135deg, #f8f9ff, #f0f2ff);
            padding: 20px;
            border-radius: var(--border-radius);
            border-left: 4px solid var(--primary);
            transition: all 0.3s ease;
            text-align: center;
        }
        
        .stat-card:hover {
            transform: translateY(-3px);
        }
        
        .stat-value {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--primary);
            margin-bottom: 5px;
        }
        
        .stat-label {
            font-size: 0.9rem;
            color: var(--gray);
            font-weight: 500;
        }
        
        /* WebP Info Banner */
        .webp-info {
            background: rgba(30, 144, 255, 0.1);
            border: 1px solid rgba(30, 144, 255, 0.2);
            border-radius: var(--border-radius);
            padding: 20px;
            margin: 20px 0;
        }
        
        .webp-info h4 {
            color: #1e90ff;
            margin-bottom: 10px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        /* Progress Bar */
        .progress-container {
            margin: 20px 0;
        }
        
        .progress-label {
            display: flex;
            justify-content: space-between;
            margin-bottom: 8px;
            font-size: 0.9rem;
            color: var(--gray);
        }
        
        .progress-bar {
            height: 10px;
            background: var(--light-gray);
            border-radius: 5px;
            overflow: hidden;
        }
        
        .progress-fill {
            height: 100%;
            background: var(--premium-gradient);
            border-radius: 5px;
            transition: width 0.3s ease;
            width: 0%;
        }
        
        /* Comparison View */
        .comparison-container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
            margin-bottom: 25px;
        }
        
        @media (max-width: 768px) {
            .comparison-container {
                grid-template-columns: 1fr;
            }
        }
        
        .comparison-box {
            border: 2px solid var(--light-gray);
            border-radius: var(--border-radius);
            padding: 20px;
            text-align: center;
            background: white;
        }
        
        .comparison-title {
            font-weight: 600;
            margin-bottom: 15px;
            color: var(--dark);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding-bottom: 10px;
            border-bottom: 1px solid var(--light-gray);
        }
        
        .image-preview {
            max-width: 100%;
            max-height: 200px;
            border-radius: 8px;
            margin-bottom: 15px;
            object-fit: contain;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        }
        
        /* Files List */
        .files-list {
            max-height: 400px;
            overflow-y: auto;
            border: 1px solid var(--light-gray);
            border-radius: var(--border-radius);
            margin-top: 20px;
        }
        
        .file-item {
            padding: 15px;
            border-bottom: 1px solid var(--light-gray);
            display: flex;
            align-items: center;
            gap: 15px;
            transition: all 0.3s ease;
            cursor: pointer;
        }
        
        .file-item:hover {
            background: #f8f9ff;
        }
        
        .file-item:last-child {
            border-bottom: none;
        }
        
        .file-item.selected {
            background: rgba(30, 144, 255, 0.1);
            border-left: 4px solid #1e90ff;
        }
        
        .file-icon {
            font-size: 1.5rem;
            color: var(--primary);
        }
        
        .file-info {
            flex: 1;
        }
        
        .file-name {
            font-weight: 600;
            margin-bottom: 5px;
            color: var(--dark);
        }
        
        .file-size {
            font-size: 0.85rem;
            color: var(--gray);
            display: flex;
            gap: 15px;
        }
        
        .file-savings {
            font-weight: 600;
            color: var(--success);
            font-size: 0.9rem;
            text-align: right;
            min-width: 80px;
        }
        
        /* Quality Indicator */
        .quality-indicator {
            display: flex;
            justify-content: space-between;
            margin-top: 5px;
            font-size: 0.85rem;
            color: var(--gray);
        }
        
        /* Notification */
        .notification {
            position: fixed;
            bottom: 30px;
            right: 30px;
            padding: 16px 24px;
            background: var(--primary);
            color: white;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            display: none;
            z-index: 1001;
            animation: slideIn 0.3s ease;
            max-width: 350px;
        }
        
        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateX(100px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }
        
        .notification.show {
            display: block;
        }
        
        /* Loading Animation */
        .loader {
            display: inline-block;
            width: 20px;
            height: 20px;
            border: 3px solid rgba(255, 255, 255, 0.3);
            border-radius: 50%;
            border-top-color: white;
            animation: spin 1s linear infinite;
        }
        
        @keyframes spin {
            to { transform: rotate(360deg); }
        }
        
        /* Responsive Design */
        @media (max-width: 768px) {
            .header-content {
                flex-direction: column;
                text-align: center;
            }
            
            .logo {
                justify-content: center;
            }
            
            .premium-header {
                padding: 20px;
            }
            
            .premium-card {
                padding: 20px;
            }
        }
        
        @media (max-width: 480px) {
            body {
                padding: 10px;
            }
            
            .card-title {
                font-size: 1.2rem;
            }
            
            .stat-value {
                font-size: 1.5rem;
            }
        }
        
        /* Format Options */
        .format-options {
            display: flex;
            gap: 10px;
            margin-bottom: 20px;
            flex-wrap: wrap;
        }
        
        .format-option {
            padding: 10px 20px;
            background: var(--light-gray);
            border: none;
            border-radius: var(--border-radius);
            cursor: pointer;
            font-weight: 500;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .format-option.active {
            background: var(--primary);
            color: white;
        }
        
        .format-option:hover:not(.active) {
            background: #e2e6ea;
        }
        
        /* Download Section */
        .download-section {
            background: linear-gradient(135deg, #f8f9ff, #f0f2ff);
            padding: 25px;
            border-radius: var(--border-radius);
            margin-top: 30px;
            text-align: center;
        }
        
        /* Premium Features */
        .premium-features {
            background: linear-gradient(135deg, #222f3e 0%, #1a252f 100%);
            color: white;
            padding: 40px;
            border-radius: var(--border-radius);
            margin: 40px 0;
            box-shadow: var(--shadow);
        }
        
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 25px;
            margin-top: 30px;
        }
        
        .feature-card {
            background: rgba(255, 255, 255, 0.05);
            padding: 25px;
            border-radius: var(--border-radius);
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: all 0.3s ease;
        }
        
        .feature-card:hover {
            background: rgba(255, 255, 255, 0.1);
            transform: translateY(-5px);
        }
        
        .feature-icon {
            width: 50px;
            height: 50px;
            background: var(--premium-gradient);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            margin-bottom: 20px;
        }