I am entirely new to blender. I am trying to create the cover of a closed book, to that end, I have made a mesh that consists of edges and vertices (it is currently only shaped properly on the left of this image, I intend to add a mirror modifier later to fix this):
I then extruded this into a 'shell':
So far, so good.
Next, I want to solidify the faces. This goes badly:
I think I understand the issue - each face gets solidified separately, and they therefore extrude different amounts, and along different normals. I just don't know how to fix it. I tried merging the faces into three faces (flat left, flat right, and bent centre), but that just removes all of the shaping.
Object mode -> CTRL-A