[bennettfeely]

The "Avoiding animation pollution" section has a few minor typos,

`transition: * 0.6s ease` won't work anyway, `*` is a selector, they're looking for a value of `all`. Omitting the transition property all together (i.e. `transition: 1s`) is what people often do but this is bad practice for the reasons they stated.

Also, for the CSS examples I believe they mean to set `.animated:hover` to `opacity: 1;` not 0.

I like the idea of using an SVG mask to make a transparent background on the jpg.