Slick Semi-transparent Button

I love this subtle glassy-looking button.

Here's my code:

background-color: rgba(45, 49, 56, 0.3); background-image: linear-gradient(rgba(255, 255, 255, 0.15),transparent); border: 1px solid #111; color: #E2E2E2; font: bold 16px; height: 30px; padding: 6px 40px; text-shadow: 0 -1px 2px black; border-radius: 9px; box-shadow: 0 1px 4px rgba(0,0,0,0.4),inset 0 1px 0 rgba(255,255,255,0.2);