I am working on web pages to be included as zipped documentation for a product, so it is expected to be unzipped and only be accessed locally via file:///
The web pages already exist, I only have to give them a facelift. They don't have CSS. I would like to add CSS. To avoid having to change thousands of pages, I'd like to insert CSS via JavaScript. The pages are in a frame (the other frame is a menu). Adding CSS from the parent window to the frame yields the error: Uncaught DOMException: Blocked a frame with origin "null" from accessing a cross-origin frame.
when trying to access the frame's document
object, for example.
Is there a way to ignore same-origin policy for web pages served this way?
This question doesn't seem to be a duplicate because it wants to use localhost