Is it possible to fit the form to the page size from the webbrowser?

Question

C++ / C#

I am writing a program for VK, when registering, a form pops up in which a log and a pass are entered and then permissions for rights are requested. The question is how to automatically adjust the size of the form to the authorization page? (the size of the page at the entrance is the same, and when permissions are granted, it changes depending on the rights)
Are there any methods for this or will it be necessary to parse the html and align the form based on it?

Answer 1

When the page loads - webBrowser.Document.Body.ScrollRectangle.Height;
webBrowser.Document.Body.ScrollRectangle.Width;