SCSS mixin to convert Photoshop drop shadows to CSS3 box-shadow
css - Box-shadow only on div corners - Stack Overflow
What is wrong with my box-shadow SASS @Mixin? - Stack Overflow
Bootstrap on Twitter: "We'll be bringing CSS variables to more components in each minor v5 release to make customization easier and even reduce file size in some cases. Consider this before and
Box Shadow SCSS Mixin - Codepad
Error: no mixin named box-shadow · Issue #597 · thomaspark/bootswatch · GitHub