:root {
            --brand-blue: #0a1d37;
            --brand-red: #d32f2f;
            --brand-silver: #f4f4f4;
            --brand-dark: #050e1a;
        }
        body {
            font-family: 'Inter', 'Segoe UI', Roboto, sans-serif;
            scroll-behavior: smooth;
        }
        .bg-brand-blue { background-color: var(--brand-blue); }
        .bg-brand-dark { background-color: var(--brand-dark); }
        .text-brand-red { color: var(--brand-red); }
        .border-brand-red { border-color: var(--brand-red); }
        
        .hero-gradient {
            background: linear-gradient(rgba(10, 29, 55, 0.9), rgba(5, 14, 26, 0.95)), 
                        url('Recursos/imagenes/fondo.jpg');
            background-size: cover;
            background-position: center;
        }

        .category-card {
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .category-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2);
        }

        .nav-link::after {
            content: '';
            display: block;
            width: 0;
            height: 2px;
            background: var(--brand-red);
            transition: width .3s;
        }
        .nav-link:hover::after { width: 100%; }

        .active-tab {
            background-color: var(--brand-red) !important;
            color: white !important;
        }

        .whatsapp-btn {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background-color: #25d366;
            color: white;
            width: 65px;
            height: 65px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 35px;
            box-shadow: 0 10px 25px rgba(37, 211, 102, 0.4);
            z-index: 1000;
            transition: all 0.3s ease;
        }
        .whatsapp-btn:hover { transform: scale(1.1) rotate(10deg); }

        .bg-brand-steel {
    background-color: #151c2a;
}