To some extend this is also down to developer having to stop trying to be clever. I can understand having something look a little weird, maybe not align 100% co

To some extend this is also down to developer having to stop trying to be clever. I can understand having something look a little weird, maybe not align 100% correctly, but how to you actively go about building something like an e-commerce site that doesn't work in Firefox? My guess is that the developers didn't actively try to do that, but used some framework that's all well an good for a SPA or something that needs to be more like a "real" application and applied that to something that just needs to be a bloody website. People need to stop doing that.