OK, i will come back next days to get a full answer for you,
but quick answer here :

1- Read the file here README

2- sources are here https://bootswatch.com/ (buttons Download)

3 - Here you get custumize b4 but xswatch was created with b3, so you need to modify some little things in files *.tpl.

Ok
tyvm : now I started to understand connections ...

Yesterday I found those pages ... but I was missing the connection with xswatch ... now I can get busy with less fear

Pino

OK ...

As I wrote , to read suggested docs , was a good thing.

I saw in both version of bootstrap the data lines for the customization of the "container-maincontainer" zone are identical ... so, probably, switching to the most recent bootstrap version would not have changed anything for me.

But this reading also made me reflect on the detail also the navmenu is contained in the same CSS class ... and what could be in the menu that could create that problem for me? One thing: the logo!

In fact the customization of the logo had led to larger sizes than those of the original Xoops logo ... in particular returning to the width of the logo within the previous measure, the problem has disappeared!
So it was my (unconscious) mistake to create this problem.

Now, the changes to the CSS that I had hypothesized are giving their result and the images are seen full screen even on mobile phones, without any problems!

Thank you everyone for the support.

Pino

Ok, good news !

Do you use smarty variables with the tag active, with the navmenu elements ?
Like $xoops_page, $xoops_startpage and $xoops_modulepage.

It's a very usefull !

Thank you Richard with this new idea here :



I didnt think use smarty tests in in class !
You show us the way to do the best with themes !

Alain,

you can also do that: https://xoops.org/modules/newbb/viewtopic.php?topic_id=76797

Quote:
Now, i used this to show my news (module xmnews) with border-color/ title/background-color with a color per category.
i like it, very clear !


You will see that soon at https://www.monxoops.fr/