Diagonal Banners in CSS

Iowa's own Caitlin Clark:

Caitlin Clark in Indiana Fever uniform #22, smiling and spinning a basketball on two fingers of her right hand. The uniform has logos for sponsors Nike, Eli Lilly, and SalesForce.

We would like to add a "NEW!" banner to this page, diagonally across the the upper right-hand corner.

Image source: Indiana Fever Media Day, May 1, 2024 (commercial image).