So i've been building up to my first website. I've been using w3schools for css codes and examples. My site is hosted via tumblr is almost complete. I could use what i have as of now. Just needs a more solid/ final theme and some unique features i want. The one biggest feature i want on my page is a hidden div that is activated by some js Function. That code is thankfully provided for me. But here is now my issue and the reason that i'm here, hoping to get an answer or a solution!
So the js code i have found is hosted on codepen. The example works perfectly. I can even modify it to my liking and it still works as intended. Here is my problem. When i copy that working code to my HTML file it doesn't work... I even start a new html file, paste everything where it belongs and it still doesn't work! I can even copy the code to http://jsfiddle.net/ & http://jsbin.com/ and those sites even work.
What is making the code i'm using not work on my pc & tumblr but works on these example sites. Is there a script src i have to install? i just don't understand why everything i've done has worked but this code.
Here is the code i'm trying to import. http://codepen.io/svinkle/pen/iBHGE