Design issues while changing font size of menu item

[ashishsthanp]

Issues

1. Design.
2. The submenu is not accessible (hover the main menu item and try to access submenu)

To replicate it, add this custom CSS:
.main-navigation a {
font-size: 14px;
}

Expected outcome:

1. The menu item should take full height and hence the border.
2. The menu item should vertically center
3. The submenu should be accessible