This is cool. If you add automatic support for the ARIA-label property (just duplicate your text content in the ARIA-label), this could be an accessibility tool. Otherwise you're basically hiding potentially needed info, which might normally be in ToolTips, from users with disabilities.<p>See <a href="https://developer.mozilla.org/en-US/docs/Accessibility/ARIA/ARIA_Techniques/Using_the_aria-label_attribute" rel="nofollow">https://developer.mozilla.org/en-US/docs/Accessibility/ARIA/...</a> for info and <a href="http://freedomscientific.com/products/fs/JAWS-product-page.asp" rel="nofollow">http://freedomscientific.com/products/fs/JAWS-product-page.a...</a> for a demo of the most popular screen reader for blind users.<p>You might also want to think about tying your CSS colors to system colors, to support users who use High Contrast mode.