- Remove now-moot taccsite_custom:frontera-cms search bar font sizes.
- Support CSS custom selectors (known external bug).
- Test CSS custom selectors (known external bug).
- Remove outdated comment from `c-branding`.
- Set `c-logo` image height in component stylesheet.
- Add TODO for `html { font-size: 62.5%; }`
- Add arrow "mixin" (note: using `%-arrow` syntax).
- Redesign header (but not dropdowns and not portal nav).
- Remove now-moot `s-portal-nav` styles.
- Add & Update header env variables for themes.
- Perform "GH-129: Do Not Support CMS Menu Nav Link & Dropdown".

Prevent dropdown link from being flagged as active.

- (Real Fix) Ensure colors are available to Docs.
- (Possible Fix) Ensure correct colors are available to Portal.\*

\* The Portal has its own settings/color.css that is almost identical.

- Load new styles solely for docs header.
- Force branding styles on old markup.
- Migrate subsite selectors from `trumps/s-header` to `tools/selectors`.
- Rename `:--in-__subsite__` selectors to `:--from-__subsite__`.
- Create new styles solely for docs header.
- Document "For (Other Sites)" i.e. `trumps/for-docs.*.css` stylesheets.

Unset Docs' `img { max-width; }`. Docs does this too but for old markup.

- Install `merge-lite` for deep merge constants and theme data.
- Use env() vars for header height.
- Remove unnecessary code and improve comments.
- Create constants for theme JSON.
- Merge constants on top of theme data.
- Update theme data comment syntax.

- Add frontera-cms logo width overwrite (temp. ineffectual, see GH-223).
- Prevent Core (but not a project) from stretching logo too wide.
- Align CMS nav for narrow logos. Allow project-specific adaptation.

- Remove redundant color assignment for nav-link.

- Add font weight constants.
- Add border constants.
- Style dropdowns and use new constants.

Use correct global var not wrong env var for branding bar bkgd.

Scope dropdown styles to header so as to not effect any other dropdowns.

1. Scope header-specific `.c-branding` styles with `.s-header`.
2. Clarify which `s-header` is being styled and why.
3. Remove `s-header` ID from sample header markup.
4. Add `s-header` class to `header-branding`.
5. Replace `s-header` ID with `header-navbar` ID.

Portal needs to overwrite Bootstrap's color for active `dropdown-item`.

Instead of defining a value to be overwritten, set a fallback.

This reduces one level of overwrite when tracking/debugging values.

Ensure Portal & Docs line-height (in header) matches CMS.

- The responsive space between nav items now considers portal elements.
- Whether header is loaded on portal is noted by presence of a class.

…design--navigation-bar