theme handbook to match rethink Gitea + rename to 'a rethink development'

Mirror the rethink Gitea theme (data-theme=rethink) on the docs site:
- docs/stylesheets/extra.css maps the exact palette onto Material's slate
  scheme: body #0a0f1f, nav #061541, text #eef1f6, primary #569bcc,
  accent #55bbff, borders #294274; square corners and blue card/table
  borders echoing the Gitea repo panels.
- Force dark-only (drop the light/dark toggle; Gitea is dark-only).
- Rename site to lowercase 'a rethink development' (site_name, copyright,
  landing H1).

Verified: mkdocs build --strict clean; rendered landing + content pages
in-browser against the live Gitea page — colors, header bar, links, and
cards match.

Signed-off-by: disqualifier <dev@disqualifier.me>

docs/index.md

@@ -1,4 +1,4 @@
-# Rethink Studios Handbook
+# a rethink development
 
 The public reference for building and shipping with Rethink Studios: our shared
 libraries, our coding standards, and how to deploy a project on our network.

docs/stylesheets/extra.css

@@ -0,0 +1,105 @@
+/* a rethink development — mirror of the rethink Gitea theme
+   palette pulled from git.rethinkstudios.io (data-theme="rethink") */
+
+:root {
+  --rt-body: #0a0f1f;        /* deep navy page background */
+  --rt-nav: #061541;         /* darker header/nav background */
+  --rt-surface: #0e1530;     /* cards / code blocks, a touch above body */
+  --rt-text: #eef1f6;        /* near-white body text */
+  --rt-muted: #aab4c5;       /* secondary text */
+  --rt-primary: #569bcc;     /* links / primary blue */
+  --rt-primary-dark: #4a8cbb;
+  --rt-primary-light: #6ba9d5;
+  --rt-accent: #55bbff;      /* bright cyan-blue accent */
+  --rt-border: #294274;      /* row dividers / borders */
+}
+
+/* Map the rethink palette onto Material's slate scheme. */
+[data-md-color-scheme="slate"] {
+  --md-hue: 222;
+
+  --md-default-bg-color: var(--rt-body);
+  --md-default-fg-color: var(--rt-text);
+  --md-default-fg-color--light: var(--rt-muted);
+  --md-default-fg-color--lighter: rgba(238, 241, 246, 0.32);
+  --md-default-fg-color--lightest: rgba(238, 241, 246, 0.12);
+
+  --md-primary-fg-color: var(--rt-nav);
+  --md-primary-fg-color--light: var(--rt-primary-light);
+  --md-primary-fg-color--dark: var(--rt-nav);
+  --md-primary-bg-color: var(--rt-text);
+  --md-primary-bg-color--light: var(--rt-muted);
+
+  --md-accent-fg-color: var(--rt-accent);
+  --md-accent-fg-color--transparent: rgba(85, 187, 255, 0.1);
+
+  --md-typeset-color: var(--rt-text);
+  --md-typeset-a-color: var(--rt-primary);
+
+  --md-code-bg-color: var(--rt-surface);
+  --md-code-fg-color: #d6deeb;
+
+  --md-footer-bg-color: var(--rt-nav);
+  --md-footer-bg-color--dark: var(--rt-body);
+}
+
+/* Header / top nav: match Gitea's dark-blue bar. */
+.md-header,
+.md-tabs {
+  background-color: var(--rt-nav);
+  color: var(--rt-text);
+}
+
+/* Links hover to the bright accent, like Gitea. */
+.md-typeset a:hover {
+  color: var(--rt-accent);
+}
+
+/* Sidebar nav active item picks up the blue. */
+.md-nav__link--active,
+.md-nav__item .md-nav__link--active {
+  color: var(--rt-primary);
+}
+
+/* Square the corners — Gitea uses radius 0 throughout. */
+.md-typeset .admonition,
+.md-typeset details,
+.md-typeset pre > code,
+.md-typeset .highlight,
+.md-typeset table:not([class]),
+.md-search__form,
+.md-typeset .tabbed-set > input:checked + label,
+.md-typeset code {
+  border-radius: 0;
+}
+
+/* Subtle blue row dividers in tables, echoing the repo list. */
+.md-typeset table:not([class]) {
+  border: 1px solid var(--rt-border);
+}
+.md-typeset table:not([class]) th {
+  background-color: var(--rt-nav);
+  color: var(--rt-text);
+}
+.md-typeset table:not([class]) td {
+  border-top: 1px solid rgba(41, 66, 116, 0.5);
+}
+
+/* Search field on the dark bar. */
+.md-search__input {
+  background-color: rgba(255, 255, 255, 0.06);
+}
+.md-search__input::placeholder {
+  color: rgba(238, 241, 246, 0.6);
+}
+
+/* Landing-page cards: surface tint + blue border like Gitea panels. */
+.md-typeset .grid.cards > :is(ul, ol) > li,
+.md-typeset .grid > .card {
+  background-color: var(--rt-surface);
+  border: 1px solid var(--rt-border);
+  border-radius: 0;
+}
+.md-typeset .grid.cards > :is(ul, ol) > li:hover {
+  border-color: var(--rt-primary);
+}

mkdocs.yml

@@ -1,26 +1,18 @@
-site_name: Rethink Studios Handbook
+site_name: a rethink development
 site_description: Libraries, coding standards, and how to deploy on our network.
 site_url: https://docs.rethinkstudios.io/
-copyright: Rethink Studios
+copyright: rethink development
+
+extra_css:
+  - stylesheets/extra.css
 
 theme:
   name: material
   language: en
   palette:
-    - media: "(prefers-color-scheme: light)"
-      scheme: default
-      primary: indigo
-      accent: indigo
-      toggle:
-        icon: material/weather-night
-        name: Switch to dark mode
-    - media: "(prefers-color-scheme: dark)"
-      scheme: slate
-      primary: indigo
-      accent: indigo
-      toggle:
-        icon: material/weather-sunny
-        name: Switch to light mode
+    scheme: slate
+    primary: custom
+    accent: custom
   features:
     - navigation.instant
     - navigation.tracking