Just wrote a new article about how to quickly create a plain HTML, CSS and JavaScript modal.
https://rapaccinim.medium.com/how-to-create-a-custom-resizable-modal-with-scrollable-and-fixed-content-21adb2adda28
https://rapaccinim.medium.com/how-to-create-a-custom-resizable-modal-with-scrollable-and-fixed-content-21adb2adda28