Changed pixel-width to percentage for loaded- and process-bar

[SimonSimCity]

I changed the pixel-calculated width (sorry for the typo in the commit-message) to percentage to gain more flexibility.

I am using it in a use-case, where the process-bar fills the whole screen-width. As this is a mobile-app, the screen-width is flexible at runtime because the user can f.e. switch from portrait to landscape.

The best way I could think of (instead of using some trigger that fires on browser-resize) was to replace the pixel calculation by percentage.