We see filterable galleries in plenty of portfolios, they're a nice and tidy way of showing off different categories of work without forcing the user to review everything. We're going to build a filterable gallery using the data attribute that came with HTML5, this way we don't have to tie everything up with classes. If you want a better idea of what we will be creating, here's a demo. The data attribute ... I mentioned in the introduction that in this tutorial we will be using the data attribute,...