- using SVG rather than Canvas, which should scale better, but is slower, so let me know if it's fast enough
- changed "Physics Coordinates" to "Coordinates: Physics"
- changed "Rotation" to "Axis" in rotation tab
- made the background of the left part of the rotation tab grey
- centered the visualization and control panel in viewport
- set particle 243 to "e \phi_X"
- made the minus signs in the symbol names wider (using the unicode minus sign "−", rather than the thing that shows up when you type "-" on the keyboard)
- made rotation work on the phone