Disqus integration issue?

Question

css

Hello. I integrated disqus comments into the site via Universal Code, everything works well with one exception: when loading comments, disqus loads its styles into the main page, thereby interrupting the assigned styles and breaking the overall layout of the page, for example, changing the indents and size of the text of headings and other elements.
I don't know why disqus behaves this way, because in fact everything should happen and load only in a certain iframe, without affecting the page itself, how can I fix this?