nav{
    position: sticky;
    top: 0;
    z-index:1000;
}

.hero {
            background-image: url('images/0.JPG');
            background-size: cover;
            background-position: center;
        }
        .activity-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
        }