For xtermjs 3.5.1, scrollbar is not working as expected.

[gangadhars]

I have tried the demo example of terminao, but the terminal is not working as expected with respect to the scrollbar for multiple device screens

For my desktop - resolution 1440x900: (Vertical scrollbar is not full)

For another desktop - resolution 1280x1024: (Vertical scrolling is good but not horizontal scrolling)

For Laptop - resolution 1920x1080: (Vertical scrolling is happening at 60% only and rows are overlapping)

Here is the code I have tried:
https://gist.github.com/gangadhars/ca38cd9a44951314f9ed0143c1b13873

How can I make terminal full height and width for all resolutions?