/* Variables CSS Premium */
        :root {
            /* Color System - Blue/Teal */
            --primary-blue: #007bff;
            --primary-rgb: 0, 123, 255;
            --secondary-teal: #17a2b8;
            --secondary-rgb: 23, 162, 184;
            --success-color: #28a745;
            --success-rgb: 40, 167, 69;
            --light-green: #20c997;
            --info-color: #17a2b8;
            --info-rgb: 23, 162, 184;
            --warning-color: #ffc107;
            --warning-rgb: 255, 193, 7;
            --danger-color: #dc3545;
            --dark-color: #2d3748;
            --light-color: #f8f9fa;

            /* Text */
            --text-primary: #2d3748;
            --text-secondary: #4a5568;
            --text-light: #718096;

            /* Spacing System */
            --space-xs: 0.5rem;
            --space-sm: 1rem;
            --space-md: 1.5rem;
            --space-lg: 2rem;
            --space-xl: 3rem;

            /* Border Radius */
            --radius-sm: 10px;
            --radius-md: 15px;
            --radius-lg: 20px;
            --radius-xl: 25px;

            /* Shadows */
            --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
            --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
            --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
            --shadow-xl: 0 20px 40px rgba(0,0,0,0.15);

            /* Transitions */
            --transition-fast: 0.2s ease;
            --transition-normal: 0.3s ease;
            --transition-slow: 0.6s ease;

            /* Typography */
            --font-primary: 'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
            background: var(--text-primary);
            min-height: 100vh;
            margin: 0;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        /* Performance optimizations */
        * {
            box-sizing: border-box;
        }

        .gpu-accelerated {
            transform: translateZ(0);
            will-change: transform, opacity;
        }

        /* Particles Background */
        .particles-bg {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 0;
            background-image:
                radial-gradient(circle at 25% 25%, rgba(255, 255, 255, 0.1) 1px, transparent 1px),
                radial-gradient(circle at 75% 75%, rgba(255, 255, 255, 0.08) 1px, transparent 1px);
            background-size: 100px 100px, 80px 80px;
            animation: particlesMove 20s linear infinite;
        }

        @keyframes particlesMove {
            0% { transform: translate(0, 0); }
            100% { transform: translate(-100px, -100px); }
        }

        /* Header Styles */
        .detector-header {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(30px);
            border: 1px solid rgba(255, 255, 255, 0.3);
            border-radius: var(--radius-xl);
            padding: var(--space-xl) var(--space-lg);
            text-align: center;
            margin-bottom: var(--space-xl);
            position: relative;
            overflow: hidden;
            box-shadow: var(--shadow-xl);
        }

        .detector-header .container {
            position: relative;
            z-index: 2;
        }

        .detector-header::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, var(--primary-blue), var(--secondary-teal), var(--success-color), var(--light-green));
            animation: headerGlow 3s ease infinite;
        }

        @keyframes headerGlow {
            0%, 100% { opacity: 0.5; }
            50% { opacity: 1; }
        }

        .detector-icon {
            width: 100px;
            height: 100px;
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-bottom: var(--space-lg);
            box-shadow: 0 10px 25px rgba(var(--primary-rgb), 0.3);
            position: relative;
            animation: iconFloat 3s ease-in-out infinite;
        }

        @keyframes iconFloat {
            0%, 100% { transform: translateY(0px); }
            50% { transform: translateY(-8px); }
        }

        .detector-icon i {
            font-size: 3.5rem;
            color: white;
        }

        .detector-icon::after {
            content: '';
            position: absolute;
            top: -5px;
            left: -5px;
            right: -5px;
            bottom: -5px;
            background: linear-gradient(45deg, var(--primary-blue), var(--secondary-teal), var(--primary-blue));
            border-radius: 50%;
            z-index: -1;
            animation: pulse-ring 2s ease-in-out infinite;
        }

        @keyframes pulse-ring {
            0% { transform: scale(1); opacity: 1; }
            100% { transform: scale(1.3); opacity: 0; }
        }

        .detector-header h1 {
            font-family: 'Poppins', sans-serif;
            font-size: clamp(2rem, 5vw, 2.8rem);
            font-weight: 700;
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 0.5rem;
        }

        .detector-header p {
            color: var(--text-secondary);
            font-size: 1.1rem;
        }

        /* Diagnostic Container */
        .diagnostic-container {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(30px);
            border-radius: var(--radius-xl);
            padding: var(--space-lg);
            box-shadow: var(--shadow-xl);
            border: 1px solid rgba(255, 255, 255, 0.3);
            position: relative;
            overflow: hidden;
        }

        .diagnostic-container::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            background: linear-gradient(90deg, var(--primary-blue), var(--secondary-teal));
            transform: scaleX(0);
            transition: transform 0.3s ease;
        }

        .diagnostic-container:hover::before {
            transform: scaleX(1);
        }

        .step-container {
            display: none;
            animation: fadeInUp var(--transition-slow);
        }

        .step-container.active {
            display: block;
        }

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

        /* Progress System */
        .progress-container {
            margin-bottom: var(--space-lg);
        }

        .progress-custom {
            height: 8px;
            background: rgba(var(--primary-rgb), 0.1);
            border-radius: var(--radius-sm);
            overflow: hidden;
        }

        .progress-bar-custom {
            height: 100%;
            background: linear-gradient(90deg, var(--primary-blue), var(--secondary-teal));
            border-radius: var(--radius-sm);
            transition: width var(--transition-slow);
            position: relative;
        }

        .progress-bar-custom::after {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
            animation: shimmer 2s infinite;
        }

        @keyframes shimmer {
            0% { transform: translateX(-100%); }
            100% { transform: translateX(100%); }
        }

        /* Steps & Questions */
        .step-header {
            text-align: center;
            margin-bottom: var(--space-lg);
            padding-bottom: var(--space-sm);
            border-bottom: 2px solid rgba(var(--primary-rgb), 0.2);
        }

        .step-number {
            width: 60px;
            height: 60px;
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 700;
            font-size: 1.5rem;
            margin-bottom: var(--space-sm);
            box-shadow: 0 10px 25px rgba(var(--primary-rgb), 0.3);
            font-family: var(--font-primary);
        }

        .question-card {
            background: linear-gradient(135deg, var(--light-color), #e9ecef);
            border: none;
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            margin-bottom: var(--space-lg);
            box-shadow: var(--shadow-lg);
        }

        /* Option Buttons */
        .option-btn {
            background: white;
            border: 2px solid #e9ecef;
            border-radius: var(--radius-md);
            padding: var(--space-md);
            margin-bottom: var(--space-sm);
            width: 100%;
            text-align: left;
            transition: all var(--transition-normal);
            font-family: var(--font-primary);
            font-weight: 500;
            cursor: pointer;
        }

        .option-btn:hover {
            border-color: var(--primary-blue);
            background: rgba(var(--primary-rgb), 0.05);
            transform: translateY(-2px);
            box-shadow: 0 10px 30px rgba(var(--primary-rgb), 0.15);
        }

        .option-btn.selected {
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
            color: white;
            border-color: var(--primary-blue);
            transform: translateY(-2px);
        }

        .option-icon {
            width: 50px;
            height: 50px;
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-right: var(--space-sm);
            color: white;
            transition: background var(--transition-normal);
        }

        .option-btn:hover .option-icon,
        .option-btn.selected .option-icon {
            background: rgba(255,255,255,0.2);
        }

        /* Results */
        .result-container {
            text-align: center;
            padding: var(--space-xl) var(--space-lg);
        }

        .result-icon {
            width: 100px;
            height: 100px;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-bottom: var(--space-lg);
            box-shadow: var(--shadow-xl);
        }

        .result-success .result-icon {
            background: linear-gradient(135deg, var(--success-color), var(--light-green));
        }

        .result-warning .result-icon {
            background: linear-gradient(135deg, var(--warning-color), #fd7e14);
        }

        .result-danger .result-icon {
            background: linear-gradient(135deg, var(--danger-color), #e74c3c);
        }

        .result-info .result-icon {
            background: linear-gradient(135deg, var(--info-color), #138496);
        }

        .result-icon i {
            font-size: 3rem;
            color: white;
        }

        .solution-card {
            background: white;
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            margin: var(--space-sm) 0;
            box-shadow: var(--shadow-lg);
            border-left: 5px solid var(--primary-blue);
            text-align: left;
        }

        /* Action Buttons */
        .action-btn {
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
            border: none;
            border-radius: var(--radius-xl);
            padding: var(--space-sm) var(--space-lg);
            color: white;
            font-weight: 600;
            font-family: var(--font-primary);
            transition: all var(--transition-normal);
            text-decoration: none;
            display: inline-block;
            margin: var(--space-xs);
            position: relative;
            overflow: hidden;
        }

        .action-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 ease;
        }

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

        .action-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 35px rgba(var(--primary-rgb), 0.3);
            color: white;
        }

        .secondary-btn {
            background: linear-gradient(135deg, var(--success-color), var(--light-green));
        }

        .secondary-btn:hover {
            box-shadow: 0 15px 35px rgba(var(--success-rgb), 0.3);
        }

        /* Navigation */
        .nav-buttons {
            display: flex;
            justify-content: space-between;
            margin-top: var(--space-lg);
            padding-top: var(--space-lg);
            border-top: 2px solid #e9ecef;
        }

        .nav-btn {
            background: linear-gradient(135deg, #6c757d, #495057);
            border: none;
            border-radius: var(--radius-md);
            padding: var(--space-sm) var(--space-lg);
            color: white;
            font-weight: 600;
            font-family: var(--font-primary);
            transition: all var(--transition-normal);
            cursor: pointer;
        }

        .nav-btn:hover:not(:disabled) {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(108, 117, 125, 0.3);
        }

        .nav-btn:disabled {
            opacity: 0.5;
            cursor: not-allowed;
        }

        .nav-btn.primary {
            background: linear-gradient(135deg, var(--primary-blue), var(--secondary-teal));
        }

        .nav-btn.primary:hover:not(:disabled) {
            box-shadow: 0 10px 25px rgba(var(--primary-rgb), 0.3);
        }

        /* Responsive */
        @media (max-width: 768px) {
            .detector-header {
                padding: var(--space-lg) var(--space-sm);
            }

            .diagnostic-container {
                padding: var(--space-md);
            }

            .option-btn {
                padding: var(--space-sm);
            }

            .nav-buttons {
                flex-direction: column;
                gap: var(--space-sm);
            }
        }