Prioritize One Style Over Another

I do all like says in page but for some reason doesn’t work, still apear like i dont add class pink-text, and dont have the pink text either, here’s my code:
Btw: sorry for my bad english im learn by myself and i need practice.

  body {
    background-color: black;
    font-family: Monospace;
    color: green;
  .pink-text {  color: pink;         
<h1 class:"pink-text">Hello World!</h1>

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Linux; Android 4.1.2; GT-I8190L Build/JZO54K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.98 Mobile Safari/537.36.

Link to the challenge:

It is class="class-name" instead of class:"class-name"

Thanks so much, that was a dumb mistake