Default plotarea size (Width: Near 400 pixels; Height: 200 pixels).
Color of title text area is non-default; Color (Wheat) of graph area is
non-default; Background color (Black) and text color (white) of legend text area
are non-default; Legend colors (Dodgerblue, Red, Orange, and Green) are non-
default.
Several other layout modifications. (Use "View Source" in your browser, if
you want to see the FORM with input data.
Even though this graph looks fine in my/your browser, the horizontal width
per x-value can easily be of unequal size if the (base) font size set in your
browser is fairly large compared to the pixel size on screen. This is of course
most likely to happen on high resolution screens, but could also be due to
unexpected setttings of the font size in browser preferences/properties.