Button doesn't align in $element

[#1]

I created an extension which basically consists of a button that when clicked shows a modal window.

Extension works fine (thanks reddys310‌).

However, the button doesn't display properly in the element's frame, when clicked it moves down and it partly cropped, even more so in edit mode. Any clues on how i can fix this ?

Thanks,

** Not aligned **

** Moves down and partly cropped after clicked **

** Cropped in edit mode **

[#2]

The problem comes from the <header> element belonging to the <article> containing the button...

So now I'm trying to either hide it or remove it, still no clues anyone ?