:root {
            /* Brand Colors - Sophisticated Palette */
            --primary: #2563eb;
            --primary-light: #3b82f6;
            --primary-dark: #1d4ed8;
            --secondary: #10b981;
            --secondary-light: #34d399;
            --accent: #f59e0b;
            --accent-light: #fbbf24;

            /* Semantic Colors */
            --success: #10b981;
            --warning: #f59e0b;
            --error: #ef4444;
            --info: #06b6d4;

            /* Neutral Palette */
            --gray-50: #f9fafb;
            --gray-100: #f3f4f6;
            --gray-200: #e5e7eb;
            --gray-300: #d1d5db;
            --gray-400: #9ca3af;
            --gray-500: #6b7280;
            --gray-600: #4b5563;
            --gray-700: #374151;
            --gray-800: #1f2937;
            --gray-900: #111827;

            /* Surface Colors */
            --bg-primary: #ffffff;
            --bg-secondary: var(--gray-50);
            --bg-tertiary: var(--gray-100);
            --surface-elevated: #ffffff;
            --surface-overlay: rgba(255, 255, 255, 0.95);

            /* Typography */
            --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
            --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

            /* Spacing Scale */
            --space-xs: 0.25rem;
            --space-sm: 0.5rem;
            --space-md: 1rem;
            --space-lg: 1.5rem;
            --space-xl: 2rem;
            --space-2xl: 3rem;
            --space-3xl: 4rem;
            --space-4xl: 6rem;
            /* Border Radius */
            --radius-sm: 6px;
            --radius-md: 12px;
            --radius-lg: 16px;
            --radius-xl: 24px;
            --radius-full: 9999px;

            /* Shadows */
            --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
            --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
            --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

            /* Transitions */
            --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-bounce: 500ms cubic-bezier(0.68, -0.55, 0.265, 1.55);
        }

        /* Dark Mode Support */
        @media (prefers-color-scheme: dark) {
            :root {
                --bg-primary: var(--gray-900);
                --bg-secondary: var(--gray-800);
                --bg-tertiary: var(--gray-700);
                --surface-elevated: var(--gray-800);
                --surface-overlay: rgba(31, 41, 55, 0.95);
            }
        }

        /* Reset & Base Styles */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-primary);
            background: var(--bg-secondary);
            color: var(--gray-800);
            line-height: 1.6;
            font-feature-settings: 'kern' 1, 'liga' 1;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        /* Premium Hero Section */
        .hero {
            position: relative;
            background: linear-gradient(135deg,
                    var(--primary) 0%,
                    var(--primary-light) 50%,
                    var(--secondary) 100%);
            color: white;
            padding: var(--space-4xl) var(--space-xl);
            text-align: center;
            overflow: hidden;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><defs><pattern id="grid" width="40" height="40" patternUnits="userSpaceOnUse"><path d="M 40 0 L 0 0 0 40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100%" height="100%" fill="url(%23grid)"/></svg>');
            opacity: 0.3;
        }

        .hero-content {
            position: relative;
            z-index: 2;
            max-width: 800px;
            margin: 0 auto;
        }

        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: var(--space-sm);
            background: rgba(255, 255, 255, 0.15);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.2);
            padding: var(--space-sm) var(--space-md);
            border-radius: var(--radius-full);
            font-size: 0.875rem;
            font-weight: 500;
            margin-bottom: var(--space-xl);
            animation: fadeInUp 0.6s ease-out;
        }

        .hero-title {
            font-size: clamp(2.5rem, 5vw, 4rem);
            font-weight: 800;
            margin: 0 0 var(--space-lg) 0;
            text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
            background: linear-gradient(135deg, #ffffff 0%, #f0f9ff 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            animation: fadeInUp 0.6s ease-out 0.2s both;
        }

        .hero-subtitle {
            font-size: clamp(1.125rem, 2vw, 1.25rem);
            font-weight: 400;
            opacity: 0.9;
            margin: 0 0 var(--space-2xl) 0;
            animation: fadeInUp 0.6s ease-out 0.4s both;
        }

        .hero-cta {
            display: inline-flex;
            align-items: center;
            gap: var(--space-sm);
            background: rgba(255, 255, 255, 0.2);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.3);
            color: white;
            padding: var(--space-md) var(--space-xl);
            text-decoration: none;
            border-radius: var(--radius-full);
            font-weight: 600;
            transition: var(--transition-base);
            animation: fadeInUp 0.6s ease-out 0.6s both;
        }

        .hero-cta:hover {
            background: rgba(255, 255, 255, 0.3);
            transform: translateY(-2px);
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
        }

        /* Premium Container */
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 var(--space-xl);
        }

        /* Section Spacing */
        .section {
            padding: var(--space-4xl) 0;
        }

        .section-header {
            text-align: center;
            margin-bottom: var(--space-3xl);
        }

        .section-title {
            font-size: clamp(2rem, 4vw, 2.5rem);
            font-weight: 700;
            color: var(--gray-900);
            margin: 0 0 var(--space-md) 0;
        }

        .section-subtitle {
            font-size: 1.125rem;
            color: var(--gray-600);
            max-width: 600px;
            margin: 0 auto;
        }

        /* Premium Calculator Grid */
        .calculator-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
            gap: var(--space-xl);
            margin: var(--space-3xl) 0;
        }

        .calculator-card {
            background: var(--surface-elevated);
            border-radius: var(--radius-xl);
            padding: var(--space-2xl);
            box-shadow: var(--shadow-lg);
            border: 1px solid var(--gray-200);
            transition: var(--transition-base);
            position: relative;
            overflow: hidden;
            group: card;
        }

        .calculator-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, var(--primary), var(--secondary));
            transform: scaleX(0);
            transition: var(--transition-base);
        }

        .calculator-card:hover {
            transform: translateY(-8px);
            box-shadow: var(--shadow-2xl);
            border-color: var(--primary);
        }

        .calculator-card:hover::before {
            transform: scaleX(1);
        }

        .card-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 64px;
            height: 64px;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            border-radius: var(--radius-lg);
            font-size: 2rem;
            margin-bottom: var(--space-lg);
            box-shadow: var(--shadow-md);
        }

        .card-title {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--gray-900);
            margin: 0 0 var(--space-md) 0;
            display: flex;
            align-items: center;
            gap: var(--space-md);
        }

        .card-description {
            color: var(--gray-600);
            margin: 0 0 var(--space-xl) 0;
            line-height: 1.7;
        }

        .card-footer {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-top: auto;
        }

        .card-tags {
            display: flex;
            flex-wrap: wrap;
            gap: var(--space-sm);
        }

        .tag {
            background: var(--gray-100);
            color: var(--gray-700);
            padding: var(--space-xs) var(--space-sm);
            border-radius: var(--radius-full);
            font-size: 0.75rem;
            font-weight: 500;
        }

        /* Premium Button */
        .btn-primary {
            display: inline-flex;
            align-items: center;
            gap: var(--space-sm);
            background: linear-gradient(135deg, var(--primary), var(--primary-light));
            color: white;
            padding: var(--space-md) var(--space-lg);
            text-decoration: none;
            border-radius: var(--radius-full);
            font-weight: 600;
            font-size: 0.875rem;
            border: none;
            cursor: pointer;
            transition: var(--transition-base);
            box-shadow: var(--shadow-md);
            position: relative;
            overflow: hidden;
        }

        .btn-primary::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: var(--transition-slow);
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: var(--shadow-xl);
        }

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

        .btn-primary:active {
            transform: translateY(0);
            transition: var(--transition-fast);
        }

        /* Animations */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }

            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @keyframes float {

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

            50% {
                transform: translateY(-10px);
            }
        }

        .float-animation {
            animation: float 3s ease-in-out infinite;
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            .hero {
                padding: var(--space-3xl) var(--space-md);
            }

            .calculator-grid {
                grid-template-columns: 1fr;
                gap: var(--space-lg);
            }

            .container {
                padding: 0 var(--space-md);
            }

            .section {
                padding: var(--space-2xl) 0;
            }
        }

        @media (max-width: 480px) {
            .calculator-card {
                padding: var(--space-lg);
            }

            .hero {
                padding: var(--space-2xl) var(--space-md);
            }
        }

        /* Accessibility Improvements */
        .visually-hidden {
            position: absolute;
            width: 1px;
            height: 1px;
            margin: -1px;
            padding: 0;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }

        /* Focus Styles */
        *:focus-visible {
            outline: 2px solid var(--primary);
            outline-offset: 2px;
            border-radius: var(--radius-sm);
        }

        .interactive {
            transition: var(--transition-base);
        }

        .interactive:hover {
            transform: scale(1.02);
        }

        .interactive:active {
            transform: scale(0.98);
        }