Drop-Shadow - Apply Shadow on Irregular Shape | Simple Web Learning
backdrop-filterの使い方解説!CSSでグラスモーフィズムを実装! - PENGIN BLOG
Haz on X: "Here's a nice trick to create drop shadows on containers with overflow elements like arrows. Instead of using the CSS box-shadow property, you can use: filter: drop-shadow(0 3px 3px