*, 
*::after,
*::before {
    box-sizing: border-box;
}
body {
background-attachment: fixed;
background-position: center;
background-size: cover;
min-height: 100vh;
overflow-x: hidden;
position: relative;
}
parallax {
background-image: linear-gradient(rgba(0,0,0,0.1), rgba(0,0,0,0.1)), url(../img/kruszywo_dekoracyjne_do_ogrodu.jpg);  
height: 25vw;
background-attachment: fixed;
background-position: center;
background-repeat: no-repeat;
background-size: cover;
display: block;
margin-top: 4vw;
text-align: center;
position: relative;
}
/*
parallax2 {
background-image: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), url();  
height: 35vw;
background-attachment: fixed;
background-position: center;
background-repeat: no-repeat;
background-size: cover;
display: block;
text-align: center;
position: relative;
}
*/
@media(max-width: 500px) {
    parallax {
        height: 75vw;
        background-attachment: local;
        margin-top: 10vw;
    }
}