The [adverts_categories] output is not responsive

See also this and this.

In .adverts-flexbox you can try replacing display: -webkit-box; with display: block; although i do not know if this will work.

I also do not want to replace flexbox althogher for three reasons:
1. this affects only older devices with Android 4.2 or older
2. it’s quite a lot of work at this point
3. flexbox allow to easily align items vertically without JavaScript

I don’t know for what both the display: -webkit-box; and the display: block; are needed, but commenting the first I solved my problem. Adding the second, as you suggested, nothing changed, so this is OK. Probably, this topic can be marked as resolved.

Ok, just to confirm when display: -webkit-box; is remove/commented page displays properly, when replaced with display: block; categories display incorrectly?

No, when display: -webkit-box; 1) is only removed/commented or 2) is replaced with display: block; categories in both scenarios are displayed correctly.

Got it, thanks for clarifying.