CSS background cut - html

Question

this is my code, and as you can see body has some background image, and #cont should be white. But I want my div elements to be transparent in a way that I can see body background image. Any CSS tricks that can do that?
body {
margin: 0;
border: 0;
padding: 0;
height: 100%;
width: 100%;
background-image: url(image.png);
background-position: center;
background-repeat: no-repeat;
background-size: cover;
}
#cont {
margin: 0;
border: 0;
padding: 0;
background-color: white;
}
#cont div {
margin: 20px;
border: 1px solid gray;
padding: 0;
width: 50px;
height: 50px;
float: left;
}
<div id="cont">
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</div>

Answer 1

here is the snippet updated:
body {
margin: 0;
border: 0;
padding: 0;
height: 100%;
width: 100%;
background-image: url(https://placekitten.com/1000/1000);
background-position: center;
background-repeat: no-repeat;
background-size: cover; /*include this*/
background-attachment: fixed; /*include this*/
}
#cont {
margin: 0;
border: 0;
padding: 0;
background-color: white;
}
#cont div {
margin: 20px;
border: 1px solid gray;
padding: 0;
width: 50px;
height: 50px;
/*float: left; replaced by display inline-block*/
display: inline-block; /*include this*/
background: url(https://placekitten.com/1000/1000) center center no-repeat; /* <<< same body image*/
background-size: cover; /*include this*/
background-attachment: fixed; /*include this*/
}
Here is the full example: jsbin

Answer 2

You can add a background-image to your div elements and play with background-position to give the illusion of being transparent.
If you're using JavaScript you can get the x/y position of the element and dynamically adjust the css.

Answer 3

Check it:-
body {
margin: 0;
border: 0;
padding: 0;
height: 100%;
width: 100%;
background-position: center;
background-repeat: no-repeat;
background-size: cover;
}
#cont {
margin: 0;
border: 0;
padding: 0;
opacity: 0.3;
}
#cont div {
margin: 20px;
border: 1px solid gray;
padding: 0;
background-color: white;
width: 50px;
height: 50px;
float: left;
background-image: url("http://www.gettyimages.ca/gi-resources/images/Homepage/Hero/UK/CMS_Creative_164657191_Kingfisher.jpg");
background-attachment: fixed;
background-position: top center;
}
<div id="cont">
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</div>