I am loving the new stacks, great idea and I have not lost my beloved scrapbook or a stack of one as they now are.
My question is this:
I have a stack that I want to add to a sidebar on multiple pages that has four blocks in it. I want to add some space between the blocks so in the stack I have added the space in Design area for each block. The stack shows the space no problem but when I add the stack to a page the space disappears.
Anyone have any ideas or suggestions?
Also, a minor annoyance... some of my stacks are wide and they overflow the stacks dialog box. Not a very polished UI. (See attached screenshot)
I have attached images to this post demonstrating how I'm attempting to reproduce this bug.
When I actually followed the more accepted upgrade method and replaced the concrete folder on my site with the concrete folder from the 5.5.1 archive (and comment out the define statement in site.php) then the stacks work as designed.
WRT to CSS, I could reproduce what you did easily enough, but what I have done is define a css class for the blocks in the stack, with the intent of styling them in my main.css, but inspecting the stack elements when added to the page, I see no sign of these css classes I had defined for the blocks.
Screenshot 1: Specifying ID and class on a block in a stack
Screenshot 2: Adding the stack to a page
Screenshot 3: Seeing the ID referenced in the header
Screenshot 4: Seeing the HTML with the block, including both the custom ID and the custom CSS class.
and insert them in between your blocks in the stack. I have found this a useful addon in the past and it avoids hacky solutions for the time being.