Refactor CSS to use standard Tailwind-style utility classes instead of
ad-hoc rules. This eliminates a lot of single-purpose rules for specific
UI elements and standardizes margins to be more consistent throughout
the site.
Utility classes are defined manually on an as-needed basis instead of
importing Tailwind as a whole. Naming conventions mostly follow
Tailwind's conventions, otherwise they follow Bootstrap.
* https://tailwindcss.com/docs/
* https://getbootstrap.com/docs/5.0/utilities/spacing/
Standardize font sizes and heading tags (<h1>-<h6>) to be more
consistent across the site.
Changes:
* Introduce font size CSS variables and start replacing hardcoded font
sizes with standard sizes.
* Change header tags to use only one <h1> per page. One <h1> per page is
recommended for SEO purposes. Usually this is for the page title, like
in forum threads or wiki pages.
* Standardize on <h2> for section headers in sidebars and <h3> for
smaller subsection headers. Don't use <h4>-<h6>.
* In DText, make h1-h4 headers all the same size. Standard wiki style is
to ignore h1-h3 and start at h4.
* In DText, make h4-h6 the same size as the h1-h3 tags outside of DText.
* In the tag list, change the <h1> and <h2> tag category headers to <h3>.
* Make usernames in comments and forum posts smaller. Also change the
<h4> tag for the commenter name to <div class="author-name">.
* Make the tag list, paginator, and nav menu smaller on mobile.
* Change h1#app-name-header to a#app-name-header.
* Remove `list-style-type: none` rules (this is the default).
* Add `list-bulleted` and `list-inline` utility classes.
* Wrap terms of service and user deletion pages in dtext `.prose` class
so we don't have to redefine basic list styles on these pages.
Position <span class="hint"> elements to the right of normal <input>
elements and underneath <textarea> elements. Fixes form hints being
badly positioned on some pages.
