snowflake_container_div = document.createElement( 'div' ); 
snowflake_container_div.classList.add("snowflakes-container");
snowflake_div = document.createElement( 'div' ); 
snowflake_div.classList.add("snowflake");
for(var i = 0; i < 100; i++){
  snowflake_container_div.appendChild(snowflake_div.cloneNode(true));
}
document.body.appendChild(snowflake_container_div);