blue_shift:
I took your advice and did a full backup before today's work.
After another hour and a half making little progress, I stripped out myCustom Script I had used to get the layout closer to the Grid4 I want - thinking that I was doing harm by overriding some Grid4 css, so yes, the div css was removed.
To clarify, I fully intend to remove Grid3 and whatever I can find that was associated with it once I update the full site to Grid4, so unless having the Grid3 elements in this installation is thwarting my efforts to get Grid4 to behave, know that I am not going to try and have both working on the site once I get this done.
So, since I did remove any custom css, then why isn't my Grid4 looking like it should for your Grid4 homepage.
Note that I also realized that custom css for Grid3 may be conflicting, so what you find on the dev.sedinaz.org site right now for the homepage should have no custom css influencing it.
And now - WAIT - I am getting to your last paragraph...:
Grid3 is being maintained, I notice 2018 Grid3 updates on their JB downloads page. And as it is T3 based, this step is playing to JA's strength. Not a layout change but you would be fully updated on Joomla and PHP and you can breathe a little
My entire effort here was to move to Grid4 ONLY because I thought it would be necessary. I had no idea Grid3 is being maintained. If that is going to be compatible with Joomla 4.0 and php 7.X, then YES, I only need to be updating Grid3.
Where did I get the mis-impression that THE update for Grid3 WAS Grid4?
Please bear with me to respond to this to be sure I move back in the right direction. I have a full backup to before I installed Grid4 and could easily take the site back there for a Grid3 update.
tmsr