Comment textarea width in theme basic sterile-dark

In the Dutch language the text editting headers wrap
to a second line, which I not really like.

I looked in the sterile-dark.css but cannot find the width line to enlarge that area so the dropdown menu does not wrap.

I am talking about the photo-page.
(I found it for the thumbnail page)

Can anybody tell me where I can change that width?

There is also the common.css but I think the comment form is basically unstyled in that theme.

Sorry, cannot find it there.

Only Buttons & Login form are configured in common.css

Yes, because it is not styled.

OK,

When the box on the image is not styled.. where can I edit the width then?

FYI
the same box on the album page is styled (I could change the width in the theme css)

[i]When the box on the image is not styled.. where can I edit the width then?[/i]
Ahm, by adding the CSS style as you need them? ;-)

Sorry, I don't know the details of the theme off hand right now.