minor fixes

Author: iliakan

7-animation/2-css-animations/article.md

@@ -443,7 +443,7 @@ The `opacity` property also never causes Layout (also skips Paint in Gecko). We
 
 Paring `transform` with `opacity` can usually solve most of our needs, providing fluid, good-looking animations.
 
-For example, here clicking on the `#boat` element adds the class with `transform: translateX(300)` and `opacity: 0`, thus making it move `300px` to the right and fade out:
+For example, here clicking on the `#boat` element adds the class with `transform: translateX(300)` and `opacity: 0`, thus making it move `300px` to the right and disappear:
 
 ```html run height=260 autorun no-beautify
 <img src="https://js.cx/clipart/boat.png" id="boat">