opera and box-shadow inset on active state

take a look at开发者_C百科 this button

In Chrome this looks fine but switching to opera you can not see the box-shadow when the button is pressed (:active). This problem only occurs when the box-shadow on :active state is set to inset i.e. like this: box-shadow: 0px 0px 10px #000 inset;

Anyone knows why this happens?

Add some border radius:

    border-radius: 1px;

with that, it works.