How to make cross browser, cross platform and all devices compatible css font stack?
You cannot guarantee the fonts that will be used on a mobile device the same way you can guarantee which fonts are available on a normal computer.
A safe bet is to use a generic font family that can be interpreted by the mobile browser to show you the relevant font, e.g.
font-family: serif; /* (e.g., Times) */
font-family: sans-serif; /* (e.g., Helvetica) */
font-family: monospace; /* (e.g., Courier) */