Embedded program has arbitrary max-width

Ive been embedding some of my Khan Academy programs in my personal website, and I want to make one of the programs take up the whole screen but theres a css property in the iframe that get generated that specifies a max-width. I can remove this property using the chrome developer tools, but since its an iframe i am unable to programmatically change this. I would like to know if anyone has a suggestion of if they can possible remove this from the current build. Im not sure what importance this property possess. Please let me know if there is any importance.

Specifically,

.scratchpad-wrap-outer > div {
    max-width: 1200px !important;
}

I would like to remove this property if possible. Im aware of the same-origin policy that prevents me from changing properties of the iframe.

https://erikostlind.github.io/