CSS box-shadow vs filter: drop-shadow() | Example For Beginners - YouTube
Adding Shadows to SVG Icons With CSS and SVG Filters | CSS-Tricks - CSS -Tricks
html - Make CSS filter: drop-shadow() goes through others elements - Stack Overflow
Haz on Twitter: "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