Can i use CSS and HTML for events, etc?

[Linkzeldafan4]

So, it hit me last night... actually this morning at 3am when i couldn't sleep if it's possible to make a scavenger hunt in HTML or CSS coding (whichever will work in conjunction with the stylesheet, portal, forums, WHATEVER) so that my members can have fun during a holiday event (like Halloween: have candy hidden on the pages) and they click them, get the "candy", and they later on cash in how many pieces they got for points.

Because of that, I need to know how to make the items vary from spot to spot, and dissapear when someone clicks them.

idk, am I dreaming the impossible here? I've seen Zelda sites do it before!