gallery preview – not full width

I am not sure what you are referring to when you say “gallery-preview” can you be a little more specific?

I chose the layout with no sidebars and set it to max width of 1.000px.
It works well with my photoblog.
The landing page (the blog) looks perfect (for me) if I post a picture (format: picture) – it fits…!

But if I take the format “gallery” and the theme builds the preview of the first three pics, then I have a gap to the right side as you can see on my site right now (https://www.geri.at).

How to avoid that…?

Thx!

Greets
Geri

If there is really no solution for it – is it possible to center the preview of the gallery (the tiles)?

Thnx!

Greets
Geri

What I found in the functions.php is:

add_image_size( 'gallery-1-thumb', 432, 432, 1 );
	add_image_size( 'gallery-2-thumb', 268, 268, 1 );
	add_image_size( 'gallery-3-thumb', 268, 164, 1 );

It’s exactly what I see with the “web developer tool” (Firefox-plugin).
But changing the attributes (for example: 432 to 500) does not taking effect on my website.

I’m not that into with writing and changing codes, maybe somebody can give me a hint…?

Thanx!
Greetings from Vienna