How to replicate Minimal 2014 design in new "Look & Feel" editor?

Thanks to the great help of this community, I was able to - with minimal to zero knowledge about CSS, JS and HTML - customize the design of my surveys to my satisfaction.
In order to accomplish what I've envisioned, I've used the old "Look & Feel" editor and based the design off the Minimal 2014 theme. From there, I added CSS and additional HTML and JS code to specific questions of my various surveys. With these adjustments, I've always been very satisfied with the way everything was set up. Now, unfortunately, I had to learn today that the old "Look & Feel" editor will be removed in February 2022.
This leads to my issue - when trying to replicate what I did in the old "Look & Feel" editor in the new editor, everything looks quite largerly different. I selected the "Blank" theme together with the "Classic" layout and included the same CSS code as in my other surveys that I've adjusted with the old editor. Still, many elements look different. I tried to analyze an older survey and insert additional code to my CSS, but this proves to be very cumbersome for someone with my level of understanding for code. Hence, I was wondering if there is any source for a full list of CSS code that would replicate the Minimal 2014 theme of the old "Look & Feel" editor, or if there is a quick and easy approach to creating one? I would imagine this would serve me well as a starting point. Thanks!