How to remove Extra spaces in the Collapse-O-matic-plugin

Hello,
I am using Collapse-o-matic plugin and its giving extra spaces which is looking quite odd.I am quite a newbie have no idea about css/php , Please help me through this.I am big time stuck with this.

link: https://lexiconhub.tk/index/java-tutorials/

Any help will be appreciated.
Thank you