Reply To: Border radius / Border / box-shadow Advanced

[Shikkediel]

The trick with border-radius is that what comes before the slash defines what happens on the x-axis and after it describes the values for the y-axis. You can use multiple values to pair each corner (like in the example) or in case of using a single value after the slash, it will apply to all defined x-axis values. When the slash is omitted, the values will be used for both x and y.

sitepoint.com/border-radius-with-slash-syntax

w3.org/border-radius

The webkit rule above is using pixels for older operating systems (or browsers) because it doesn’t handle percentages well.

In short for box-shadow, it stacks a whole bunch of them.