Reshape Shape on Mobile to fit entire screen horizontally

I'm hoping someone will be able to help me as it has been complete disappointments one after the other when editing my site 😪. I'm currently trying to create an "overlapping" section on my mobile view as it works perfectly on my desktop. For desktop I could simply drag the square shape to fit the screen and I was good to go. The mobile version has proved to be extremely frustrating to customize. I'm attempting to stretch the shape and found the following code to do so. It worked perfectly for expanding the shape to the right side from the center, but the left side remains unchanged. Could someone please help me see what I'm missing and how I can get the shape block to expand both ways to fit the entire width of the mobile screen?

Custom CSS Code used:

@media only screen and (max-width:640px) { #block-yui_3_17_2_1_1712520327346_28446 {width:500%}}

Can you share link to this page? We can check easier

Hello, 

Thank you for your reply! I was able to figure it out.