(It was nothing) Glitch? Bug? Forgetful mod? or am i not seeing this right

Question

On Javascript tutorial DOM and Events(Creating animations), they show you how to make 2 boxes in javascript. but when i click try it yourself, it just has a comment saying that the code would be put there. so i copy/pasted the code from the tutorial to the interpreter, and it said i did something wrong. Then I realized that both the boxes were made with css!

sololearn.com/Play/JavaScript
code.sololearn.com/961/#js

Answer 1

They don't show you how to make 2 boxes in Javascript. They show you how to animate a box (made with HTML and styled with CSS) using JS. The complete code can be seen later in that lesson.

Answer 2

thankt you