This is a remix, a thorough one. The original desing had to be scaled up to properly fit the lid and SD cards. This new design adds some clearings and other features to make it easier to use.

Improvements:

• Added tollerances to the lid dimensions for better fitting.
• Added little bar extrusions to make the lid snap in position
• Angled the bottom part of the slot were the SD card fits in. The bottom part is now a bit narrower. This applies a bit of pressure on the sd card and keeps it in place.
• Added dents in the lid and base so that you have more grip when opening the box
• Rounded all corners in the printing plane for smoother, faster printing

TODO

• I printed the design, it is ok, but it can be a bit hard to remove the SD cards, especially when the box is full. It also depends on the brand of SD card. In a future redesign, I would make the slots straight on one side to reduce the clamping force. On the other hand, now you do not need to worry about the cards comming loose.
• Lid fids perfectly on my printer, I'd reduce the tolerances a bit to make it stick just a tiny bit better, i.e. -0.05mm

If you have fusion 360, I added the fusion 360 files. It should be rather straightforward to do these modifications. Let me know if you adapted it, or better, post a remix!

Cheers!