:root {
            --primary-color: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary-color: #7c3aed;
            --success-color: #10b981;
            --danger-color: #ef4444;
            --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        }

        body {
            font-family: 'Poppins', sans-serif;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
        }

        .hero-header {
            background: var(--bg-gradient);
            color: white;
            padding: 3rem 0;
            margin-bottom: 2rem;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
        }

        .hero-header h1 {
            font-weight: 700;
            font-size: 2.5rem;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
        }

        .hero-header p {
            font-size: 1.1rem;
            opacity: 0.9;
        }

        .card {
            border: none;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
        }

        .intro-card {
            background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
            border-left: 5px solid var(--primary-color);
        }

        .intro-card .card-title {
            color: var(--primary-color);
            font-weight: 600;
        }

        .intro-card .icon-box {
            width: 60px;
            height: 60px;
            background: var(--bg-gradient);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
        }

        .intro-card .icon-box i {
            font-size: 1.8rem;
            color: white;
        }

        .instruction-item {
            display: flex;
            align-items: center;
            padding: 0.75rem;
            background: #f8fafc;
            border-radius: 8px;
            margin-bottom: 0.5rem;
        }

        .instruction-item i {
            font-size: 1.5rem;
            margin-right: 1rem;
        }

        .instruction-item.like i {
            color: var(--success-color);
        }

        .instruction-item.dislike i {
            color: var(--danger-color);
        }

        .me-gusta {
            color: var(--success-color);
            font-weight: 600;
        }

        .no-me-gusta {
            color: var(--danger-color);
            font-weight: 600;
        }

        #alerta {
            border-radius: 12px;
            border: none;
            box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
        }

        .btn-primary {
            background: var(--bg-gradient);
            border: none;
            padding: 1rem 3rem;
            font-weight: 600;
            border-radius: 50px;
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
            transition: all 0.3s ease;
        }

        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
            background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
        }

        .results-card {
            background: linear-gradient(135deg, #ffffff 0%, #f0fdf4 100%);
            border-top: 4px solid var(--success-color);
        }

        .results-card .card-header {
            background: transparent;
            border-bottom: 2px solid #e5e7eb;
            font-weight: 600;
            font-size: 1.2rem;
            color: var(--success-color);
        }

        .footer {
            background: #1e293b;
            color: #94a3b8;
            padding: 2rem 0;
            margin-top: 3rem;
        }

        .footer a {
            color: #60a5fa;
            text-decoration: none;
        }

        .footer a:hover {
            color: #93c5fd;
        }

        /* Animación de entrada */
        .fade-in {
            animation: fadeIn 0.6s ease-out;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* Responsive */
        @media (max-width: 768px) {
            .hero-header h1 {
                font-size: 1.8rem;
            }

            .hero-header {
                padding: 2rem 0;
            }
        }