I always have questions like: “Can I have such a path -> ul > div > li ?” I never know how to google these questions as it would work but wouldn’t verify. Is there a resource that explains, in simple english (not w3), what I can and can’t do?
I always see people saying you can’t have a bar inside a foo and so on. Where can I find this out?
You can use the W3C HTML validator or if you’re using Firefox you can install the HTML validator addon, these tools will tell you about problems like the one you mentioned in your question and they work according to the W3C resources.