Update _header-nav.scss
- Fix https://github.com/paritytech/fether/issues/149 - I didn't find it very disturbing to not have the "button" effect.. but I am not 100% convinced... need your feedback
- Fix https://github.com/paritytech/fether/issues/149 - I didn't find it very disturbing to not have the "button" effect.. but I am not 100% convinced... need your feedback