Is there a Safari equivalent for scroll-behavior: smooth;?

Safari 15.4 adds support for CSS scroll-behavior as detailed in the 15.4 release notes.

Added support for the CSS scroll-behavior property and ScrollOptions, allowing smooth scrolling to anchors or via JavaScript.

Safari does not support scroll-behavior: smooth, you'll need some custom javascript to achieve the same effect. See this: Javascript - window.scroll({ behavior: 'smooth' }) not working in Safari