:root {
            --color-body-bg: #f9fafb;
            --color-white: #fff;
            --color-primary-blue: #1d4ed8;
            --color-primary-dark: #1e40af;
            --color-gradient-start: #667eea;
            --color-gradient-end: #764ba2;
            --color-text-main: #374151;
            --color-text-secondary: #4b5563;
            --color-border-light: #dbeafe;
            --color-divider: #f3f4f6;
            --radius-lg: 0.75rem;
            --radius-xl: 1rem;
            --padding-lg: 1.5rem;
            --shadow-xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);
            --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
        }

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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, var(--color-gradient-start) 0%, var(--color-gradient-end) 100%);
            min-height: 100vh;
            padding: 2rem 1rem;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
        }

        /* Header */
        .header {
            text-align: center;
            margin-bottom: 3rem;
            color: white;
        }

        .header h1 {
            font-size: 3rem;
            font-weight: 800;
            margin-bottom: 0.5rem;
            text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }

        .header p {
            font-size: 1.25rem;
            opacity: 0.95;
        }

        /* Calculator Grid */
        .calculator-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 2rem;
            margin-bottom: 3rem;
        }

        @media (min-width: 768px) {
            .calculator-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        /* Calculator Card */
        .calculator-card {
            background: white;
            border-radius: var(--radius-xl);
            padding: var(--padding-lg);
            box-shadow: var(--shadow-xl);
            border: 1px solid var(--color-border-light);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .calculator-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 10px 10px -5px rgb(0 0 0 / 0.04);
        }

        .card-icon {
            font-size: 3rem;
            margin-bottom: 1rem;
        }

        .card-title {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--color-primary-dark);
            margin-bottom: 0.75rem;
        }

        .card-description {
            color: var(--color-text-secondary);
            line-height: 1.6;
            margin-bottom: 1.5rem;
            flex-grow: 1;
        }

        .card-features {
            list-style: none;
            margin-bottom: 1.5rem;
        }

        .card-features li {
            color: var(--color-text-main);
            font-size: 0.875rem;
            padding: 0.5rem 0;
            border-bottom: 1px solid var(--color-divider);
        }

        .card-features li:last-child {
            border-bottom: none;
        }

        .card-features li::before {
            content: "✓ ";
            color: var(--color-primary-blue);
            font-weight: bold;
            margin-right: 0.5rem;
        }

        .card-button {
            display: inline-block;
            background: linear-gradient(135deg, var(--color-gradient-start) 0%, var(--color-gradient-end) 100%);
            color: white;
            padding: 0.75rem 1.5rem;
            border-radius: var(--radius-lg);
            text-decoration: none;
            font-weight: 600;
            text-align: center;
            transition: opacity 0.3s ease, transform 0.2s ease;
        }

        .card-button:hover {
            opacity: 0.9;
            transform: scale(1.02);
        }

        /* Footer */
        .footer {
            text-align: center;
            color: white;
            opacity: 0.9;
            padding: 2rem 0;
        }

        .footer p {
            margin-bottom: 0.5rem;
        }

        /* Responsive adjustments */
        @media (max-width: 767px) {
            .header h1 {
                font-size: 2rem;
            }

            .header p {
                font-size: 1rem;
            }

            body {
                padding: 1rem 0.5rem;
            }
        }