This mod (Fabric) allows you to add lots of different Minecraft blocks.
It also adds some variations like vertical blocks and new quarter blocks.

These are new variations that don't exist in Minecraft.
They will allow you to detail your constructions enormously.

There are also stairs and slabs (vertical) for all blocks of Minecraft. A dream come true.

Additional blocks and items
You also have the option of adding grass to the dirts slabs.
As well as other small details...