Hello everyone, I have a problem with my IKEA Billy bookcase: over time, the doors have warped so they no longer close properly and in some places even let air in from the sides. I am interested in methods to correct warped doors on this model without having to replace the entire bookcase or the doors themselves. Are there any proven tricks, such as adjustments to the hinges, effects of humidity, or mechanical refinishing, that I could do myself as a skilled DIY user? So far, I have tried tightening the hinge screws a bit, but without success. I am looking forward to your tips and experiences.