Inset and Multiple Shadows

To create an inset box shadow, add the inset keyword.

To include two shadows we cover all four sides: one shadow for the top left, and one for the bottom right.

To add multiple shadows to an element, simply need to repeat the same syntax again, separated with comma.

snippet
-webkit-box-shadow:
inset 1px 1px 84px rgba(0,0,0,0.24),
inset -1px -1px 84px rgba(0,0,0,0.24);

-moz-box-shadow:
inset 1px 1px 84px rgba(0,0,0,0.24),
inset -1px -1px 84px rgba(0,0,0,0.24);

box-shadow:
inset 1px 1px 84px rgba(0,0,0,0.24),
inset -1px -1px 84px rgba(0,0,0,0.24);
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