How to reduce the amount of space between index pages?

You can send your question to my email to get faster answer. / How to Setup Password & Share URL 

-- I'm Tuan. I work for a non-profit project (promote the establishment of free libraries). I check the forum once or twice a day to help out the community. If you don't see me answering your question, you can send it to the email above. There are so many questions every day so I can't answer them all at once, I will try to answer them in the next few days.