From the official GRAV documentation:
The concept of Modular Pages is a little tricky to get your head around at first, but when you do you'll see how convenient they are to use. A Modular Page is a collection of pages stacked on top of each other to create a unified, single page. This lets you create a complex page-structure by using the LEGO building-brick-approach, and who doesn't love LEGO?!
To add a modular, you must first create a modular page.
I everything goes well, the ui should look something like this.
No content is entered in this page per see. Save your progress if you need to and we are ready to add a modular to our modular page.
We will now add a modular using the relatively unopionated Content modular, mainly used for text, embedding stuff (images, videos) and using shortcodes.
From the Page section or from inside any page...
This here theme adds a small twist to modular foundation by adding color theme and spacing controls on all of them. If you head to the Options tab in a modular you'll see pretty much this...
Little monkey dev is slow at writing documentation. Come back soon.