I have a page written in Vue.js and Vite.js, and while I'm scrolling from top to bottom of the page, the theme changes. I thought that fixing linear-gradient CSS (see commit here will fix the issue, however, it didn't. The page source can be found here. This is a specific issue happening only in Safari browser.
(Safari) Page theme changing from dark to light while scrolling on Vue.
You might have better luck asking this question over in Apple Support Communities run by Apple Support.