You have entered the official lair of Qzekrom (Cute Zekrom), where he spends most of his time chain-smoking, drinking, insider trading, and most importantly, having fun. Proper attire is required.
Note that the previous statement where Cute Zekrom insulted your tank tops was a joke.
Anyway, this is where Cute Zekrom tests out new HTML5 and CSS features that will cause you to be electrocuted if you dare enter this high-security area without proper identification. Eventually, these features will make it to other places in my userspace, such as my userpage and signature. And possibly even to mainspace articles.
If you have any suggestions as to what I can do to improve any userspace page, feel free to ask me. Do not edit userspace pages without permission, except for this one (because it's a designated sandbox).
Don't think the talk page for the sandbox will ever be a sandbox.
I'm spending quite a bit of time fine-tuning my userpage aesthetic API. Please feel free to check it out and possibly give me feedback. Perhaps the grayscale is kind of plain-lookin'.
I especially like what Joe9320 did. He used most of my API templates and modified the header so it wasn't just gray and black, but also added some blue elements. I appropriated that and added multiple borders and a glowing effect to my version using the box-shadow CSS3 property.