I am learning CSS and using Chrome dev tool to check the size and position of a div element.

But the value on the right side of the "position box" for the div is negative. I don't know where it comes from.

What does this value mean? How can I find out what is causing this negative value?

The -0.8 in the picture is the value I am asking for.

This div has some children, and partial style for the div is like this:

 position: fixed;
 top: 0;
 left: 0;

 width: 100%;
 height: 67.2px;

 padding-left: 2em;
 padding-right: 2em;

In the console, with the div selected, if I do

$0.getBoundingClientRect()

it will give following details:

DOMRect {x: 0, y: 0, width: 376, height: 67.20000457763672, top: 0, …}
bottom: 67.20000457763672
height: 67.20000457763672
left: 0
right: 376
top: 0
width: 376
x: 0
y: 0