- Set an explicit `display: flex` on the base `.nav` class and remove the floats/clearfixes from our navs.
- Set some global styles for `.nav-link`, a departure from the previous solution that featured no predefined padding.
- Move `.nav-link` from `inline-block` to `block` given this setting was added for our tabs and pills anyway.
- Remove horizontal margin from nav tabs; let folks set that on their own from now on.