CSS Image Creation


I dont think the tutorials on creating images is in depth enough. Take this following lesson, I could almost follow and get an idea as to why I was doing each thing, but when it comes to the adding an empty string in the before element to mirror the after element and create a heart… I am lost. I have a bit of an in depth approach to things and like knowing why what I am doing does what it does.

Is there any other resources out there that explain this more in depth?