materia mate calculator button spacing is too close

[LoveChocoCat]

i have issues with the mate calculator app button spacing si too close so it is a bit hard to see each different key

this is the with one of default mate themes

the materia version is this materia-theme-git-r666.448d505-1
the gtk+ is 3.22.29
my distro is arch linux
how to reproduce the problem step is just open the mate calculator app
can i have a suggestion i think you have to adjust the shadow and the spacing a little bit far from each button so it is more easy to see

[nana-4]

I reported this issue to the upstream app, since I thought this is rather an upstream issue.

Also this app doesn't have any specific style classes, so it's difficult to control the style by the theme.