"Save on quit" doesn't work on browsers if you close the tab. So you should always manually save or have auto-save on low frequency. But unless you disabled auto-save completely and didn't have a previous save, I'm not sure what would cause you to lose all progress.
I do not plan to support Mac because I do not own one. Unfortunately one cannot easily install macOS like one can Linux to compile for it. Also only 2% of steam users use mac, so prospects aren't great, sorry. Would be cool to know if it works with Whisky though.
yeah I don't know what happened with the save, but I'm not too worried about it. I had only done 1 prestige so I wasn't crazy far in. And no worries on Mac support, I never expect devs to plan on supporting Mac, especially if it's 1 dev or a small team, but I am always curious. I appreciate the answer and some shared confusion lol. I do use safari, so that very well might've messed with something. safari typically has some weird issues with browser games sometimes.