fizzbuzz.css

ul{
  list-style-type:none;
  counter-reset: section;
}
li:before {
  counter-increment: section;
  content: counter(section);
}
li:nth-child(3n):before, li:nth-child(5n):before{
  content: "";
}
li:nth-child(3n):before{
  content:"Fizz";
}
li:nth-child(5n):after{
  content:"Buzz";
}

fizzbuzz.js

ul = document.createElement("ul")
for(i = 1; i <= 100; i++){
  li = document.createElement("li")
  ul.appendChild(li) 
}
document.getElementsByTagName('body')[0].appendChild(ul)

link.txt

http://codepen.io/anon/pen/Mwyqyw