Need help with list-view column-width

[zimmer-media]

Hi everyone.

I would like to get the 2 columns in the list view in the width exactly the other way round.
As a solution, I already had the two divs in the tpl file swapped and entered by float in the css. In the view via PC it is ok, but it does not look very good in the view on mobile devices.
I would like to have the div with the picture wider, since the main pictures are almost all narrow. The div with the short text should become narrower.
The size of the images are then adjusted via the picture option and css code.
If someone has a solution to adjust the <div class = "left-block col-md-4 col-sm-4"> and <div class = "right-block col-md-8 col-sm-8"> From?
Somehow I do not find the corresponding code.

Thanks in advance.

PS 1.6.1.1
based on LeoTheme
 
http://roxotech.de/5-tshirts
 

Edited November 12, 2016 by zimmer-media (see edit history)

[zimmer-media]

Can someone please help