Fixed background in HTML5 CSS3

Question

I put a background x on my site, with the css code:

body
{
    background-image: url("../imagens/back.jpg");
    background-color: rgba(64, 118, 182, 1);
    background-repeat: no-repeat;
    background-size: auto;
}

I wanted the image not to repeat, but to stay fixed on the screen, when the user scrolled would not change the background of the site, the background would continue in its place.

Answer 1

Add:

background-attachment: fixed;

See this example of W3C