* Replace divs with semantic markup
Replace `<div>` tags with `<nav>`, `<aside>`, and a list for the nav items.
* Use grid layout
Replace flexbox with CSS grid layout. The right-hand side item is now in its own
grid cell, so the text wraps inside its cell at smaller screen widths.
Undo `<nav>` tag.
* Sort CSS
Sort the remaining CSS property declarations.
* Fix right alignment issue in Safari
Remove `justify-self: end` to fix the right alignment issue in Safari.
* Fix vertical alignment in Edge
Add `align-self: center` but only for MS Edge.
Also removed `position: relative` on the wrapper element for the tabs.
As the help item isn't using absolute positioning anymore we don't need
to set relative positioning on the parent element.
Ian Oxley
8438cf0578