Multiple column design in blog

Site URL: https://corn-apricot-zn88.squarespace.com/

Hello -

My boss doesn't like the 3 columns I have on our project pages. Basically I just wrote code to make it read 3 columns, but because of the way the text works and the colors/style I custom added, the main text floats beneath the "data set on on the far left" depending on the width of the window. Is there any way to make it so there is ONE left column and then a separate block to the right that has 2 columns?

The only way I can think of it may be to move everything via block ID#, but I have over 75 project pages and that seems cumbersome. I did try to add a code block, but they didn't like the way that looked either. the title is a code block so if I try to use .code-block etc., it changes ALL my code blocks

I need something static as I will not be the only one editing and the drag/drop in the blogs is easy to mess up. 

First image is how it looks on my wide screen. Second is how it looks on Boss' screen. They want it to always look like the first one.

Thank you!