How can I resize content from code imbed feature?

Hi everyone,

I am currently working on a website for a client, and they requested to include live data feedback from a voting feature from a website called mentimeter. I have used the code imbed feature in the elements section, and the code works well for desktop, however I am unable to change the properties of the contents within the section. I have tried to make changes to the actual code in the element properties, where the code is visible but making changes to height, width, or any other value does not make any change to different breakpoints. Can any one tell me if this can be done? Or does the original website (mentimeter) not allow to make css changes to the embed code?

Here is my site Read-Only:

You can’t edit iFrames