If the font has a name that consists of multiple words, you'll have to write them with quotation marks. So
Code:
//one word fonts
Tungsten, Helvetica, sans-serif
//multiple word fonts
"Blender Pro Book", "Helvetica Neue", sans-serif
//or combined
"Blender Pro Book", Tungsten, sans-serif
Having to write complex font names with quotations is part of CSS specification: http://www.w3schools.com/cssref/pr_font_font-family.asp
For multiple versions of Tungsten you will still have to create multiple custom fonts. CSS does not support font versions when you specify a font-family - you can define font-weight, font-style, font-size, but it is not possible to have your browser automatically pick Tungsten-Light or Tungsten-Medium depending on which font-weight you choose. For all purposes, these are seen as 2 separate fonts and should be used that way.
Take a look at further font CSS specification here: http://www.w3schools.com/cssref/pr_font_font.asp and also in Animator documentation: http://docs.sencha.com/animator/1.5/...ion-type-base-