Portfolio Raster – Grid Entry Breaking Point (4 columns)

Hi!

I’m facing some troubles with the portfolio raster elements breaking point.

I’m using a 4-column portfolio raster which gets displayed well on big screens (desktop).
But if i have a smaller screen/viewport – let’s say 1000px – it’s shrinking too much.
I would like to have an earlier breaking point with steps to 3-col, 2-col, and so on, until 1-col on mobile.

Or in other words: I would like to have a min-width for the single grid-entries.

I have modified the portfolio raster shortcode, now it contains more elements, like:
Image, Title, Sub-Title, Button, …
In order to get a nice looking output, i need to specify a certain min-width.

Logic should be like this:

IF total width of raster is smaller than the sum of min-width 4-col entries
THAN break after 3 (to achieve specified min-width)
IF total width of raster is smaller than the sum of min-width 3-col entries
THAN break after 2 (to achieve specified min-width)

Let’s say min-with should be 300px:
4-col would be 1200px (which is ok on big screens)

On a 1024px-width screen it should be 3-col, which would be 900px (sum of 3 grid-entries).
But at the moment i still have 4-col with shrinked grid-entries (about 250px in width)

Hopefully i described it well enough.
Are there any options/rules to achieve my desired min-width / breaking point?
Thanks in advance!