Heat Map question from Question Library: Modifying for mobile screens

Hi,

I need to modify the Heat Map question from the Question library, so that the regions dimensions could be changed if the screen is less than 800px. I just have 4 zones on the Image and I'm using the On-Off triangle example to select and de-select these zones.

The dimensions that I've given in the initializeSvg method and on which I've based the cut-off of the regions, are too large for a mobile respondent. I need to be able to modify it for a smaller screen.

Any guidance would be helpful.

Thanks