Sections Width Changing on interactions

Please help!

Im trying to re-create something similar to this layout:

Im trying to create the effect when someone clicks “reading mode” the left section goes off screen and the right section takes up 100% width

Please help. Thanks!!

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Hi @anthonymas your public share link doesn’t work, can you please edit it ?