For me it looked fully correct in firefox for android (the actual website, not just the screenshot). It only made the app stop responding to button presses (not the first time it does that, fortunately restarting it fixes it and it can remember all its tabs)
Lynn Fisher has also a great website that inspires me regularly. She draw using css and 1 single div. It's all about linear-gradient background. Very interesting.
Firefox and Chrome seem render it flawlessly and Edge's performance isn't half bad either, but I am honestly surprised at how well it works even in IE11.
At this point someone should just make an SVG to CSS converter then you could export from Illustrator or whatever to CSS and be done with it. NOTE: not suggesting CSS should be used this way.
I wonder if it would be harder to make this in .css vs .less. It would be cool to see some hand written SVG as generated SVG is always ugly and bloated.