Added a little color and changed the font

No major changes, although I really wanted to create my own sprites to replace the default checkboxes. I just wanted to practice cloning, editing, and submitting a PR with git.
For these types of selectors I would lean towards a more descriptive class based selector rather than depending on a strict HTML structure/tag combination.

General rule of thumb: Never use generic html elements `div, span, section` or IDs `#some_id` within selectors. Class based selectors always win when it comes to modularity/fragility/reusability/sanity :smile: 

Example: instead of enforcing that "`form`'s immediate children who are `div`'s" you could rather do something that expresses ... "This element gets an emphasis on hover" ... maybe something like

```css
.hoverable {/*Base Styles*/}
.hoverable:not(:first-child) {/*All but first child*/}
.hoverable:hover {/*Hover specific styles*/}
```

This would be more flexible (and actually, I think if you browse to the version (https://rawgit.com/suwdc/todo-learning-playground/master/index.html) you will see how the added specificity of the `form > div` selector falls apart when any change to structure is introduced.

No worries. Just FYI @laklein I merged it as-is.