What page(s) did you find the problem on?

https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Background_and_Borders/Border-image_generator
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Background_and_Borders/Border-radius_generator
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Background_and_Borders/box-shadow_generator

Specific page section or heading?

Their URL

What is the problem?

These pages are in the CSS_Background_and_Borders directory, but it seems a misspell of CSS_Backgrounds_and_Borders.

What did you expect to see?

They should be in
/docs/Web/CSS/CSS_Backgrounds_and_Borders/
(which already exists) instead of
/docs/Web/CSS/CSS_Background_and_Borders/