How to set background for parallax?

Question

css

In general, you need to do this so that the blocks go along the grid inside on top of the background. Yes, this is definitely parallax, but I need one fixed background, and so that all the blocks float on it without moving anything. Like here approximately, only there is one large block, but I need the blocks to be small and if there was a distance between them, then it was transparent https://7themes.su/
googled this option, but apparently it doesn’t quite fit. https://codepen.io/jaukia/pen/jQEYQQ
there are strange blocks, and bg does not work for html, body is not displayed) website) Does anyone have a bike? What not to invent))

Answer 1

Add a property to the background.
background-attachment: fixed

Answer 2

Here is a complete list of how to set the background
.paralax3 {
/* The image used */
background-image: url("../img/1.jpg");
/* Create the parallax scrolling effect */
background-attachment: fixed;
background-position: center;
background-repeat: no-repeat;
background-size: cover;
}