.hero-bg {
    background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.8)), url('https://images.unsplash.com/photo-1492691527719-9d1e07e534b4?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}