Hello everyone! I'm having issues with unwanted gaps showing in Outlook 2007, 2010, 2013, 2016.

Currently, I have a section of numbered images all in one row. It’s a 2 column-nested table with two th’s with responsive code (so it’ll stack on mobile) and tables within them. It’s rendering just fine in most clients except in Outlook 2007, 2010 (+dpi version), 2013 (+dpi version), 2016. There’s an unwanted gap showing up between the two columns.

Below is a codepen link to my html code.

Would appreciate anyone’s help! Many thanks!