`no-repeat center / 10.6rem`
The correct syntax is `<position> / <size>`. These buttons for video are not shown correctly:
![device-2013-07-03-155750](https://f.cloud.github.com/assets/2406290/741752/6682affc-e3b6-11e2-9eef-11ed35f17bdc.png)
![device-2013-07-03-155912](https://f.cloud.github.com/assets/2406290/741753/781f6944-e3b6-11e2-9928-7292b4f6f463.png)