Firebug on Mac problem

I have a problem with firebug. When click inspect shows css but when move cursor from the block to editor css windows changes and shows something else most the body CSS
On PC this works but on mac, i have problem changing css with firebug.

For HTML, click the elemement your want to edid (so that it’s highlighted) then click the Edit button (top left of the Firebug window).

To edit CSS with FB, click the CSS tab, choose the style sheet that you want to edit in the drop list (if there’s more than one), then Click the Edit button.

I’ve only seen that happen if I was hovering over a link on the site, so the CSS shows the hover styles for that link. If you mouse away from that link, the css window returns to the non-hover styles.

I like the way firebug works
I open firebug, inspect an element
and at the right bottom shows current CSS
when move the cursor to that window, CSS window update css to another element, so i cannot change CSS

I don’t really understand what you are describing here, but anyway, the best way to edit the CSS is to have the Web Developer Tools handy, and go to Tools > Web Developer, CSS > Edit CSS

How can select what element i need to edit?