Fix jQuery DIV Scaling Issue

We are currently experiencing an issue with a piece of jQuery code to scale an advertising iframe. Attached is a ZIP archive containing the relevant files demonstrating the problem.

In index.html, the iframe within the DIV "blurb" is intended to be responsive, but the right hand side of the image is cut off between 548px and 1919px.

The iframe is inside a flex container. The width and height of the flex container appears to scale correctly. The height of the iframe also appears to scale correctly. However, the width of the scaled iframe is not 100% of the flex container, so the right side of the iframe is cut off. The relevant code is located between lines 601-633.

This is a simple project. All of the necessary code is provided. It just requires a little fine tuning. For this reason, our budget is fixed at $100. (we could do it ourselves, but we have neither the time or patience to mess around with it).

IMPORTANT:
We are looking for a reliable jQuery expert, who instantly recognizes the problem, and can fix it a.s.a.p. If you do not know how to fix the problem, then do not submit a proposal.