Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. 
0 seconds of 0 secondsVolume 90%
Press shift question mark to access a list of keyboard shortcuts
Keyboard Shortcuts
Play/PauseSPACE
Increase Volume↑
Decrease Volume↓
Seek Forward→
Seek Backward←
Captions On/Offc
Fullscreen/Exit Fullscreenf
Mute/Unmutem
Seek %0-9