I need a way to automatically make Panel layouts responsive Before I asked this question I did a humble Google research for several times but I really couldn't find any efficient solution for this problem. I consider a working answer to be a grace with the community:

Until now, I haven't had many panels in my sites (say no more than 1-2 mini Panels + 1 panel page, per site). I made each Panel responsive by per block elements. I must say that could take some time and it's surly not an efficient solution when you have many panels in your site...

Therefore, I am looking for a way to automize this process - Instead of making any panel layout responsive manually, I need a way (maybe even a general CSS code piece if not a module) just to ensure my panel layouts will be responsive, and an example would be:

instead of width: 50%+50% or 33%+33%+33% float\text-align: right\left, all will be centered).

So, how can you to "Auto-responsify" all existing panels, including all panels to come, in a site?
I think the closest you're going to get to out of the box is Panels Extra layouts, which ships with a bunch of adaptive layouts.

Other than that, your best bet is just to create a bunch of custom layouts by yourself, with their respective templates. The documentation is not bad for that; you can find it here: Panels 3: Creating a custom layout in your theme. Alternatively, just look in the Panels codebase for their implementations.