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
CSS로 보다 아름다운 Shadow 만들기(filter: box-shadow vs drop-shadow)
CSSのdrop-shadow()関数を使って透過画像に影をつける | Free Style
Breaking down CSS Box Shadow vs. Drop Shadow | CSS-Tricks - CSS-Tricks