fix: vendor brand CSS and remove private repo fetch (#7)

The curl fetch from the private brand repo returns 404 on public
CI runners, breaking all docs styling. Vendor the CSS directly,
remove the fetch step, and strip the hero-glow div that no longer
has backing styles.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: Fieldnote-Echo

.github/workflows/docs.yml

@@ -29,10 +29,6 @@ jobs:
       - name: Install docs dependencies
         # For library repos, remove --no-install-project so the package is importable
         run: uv sync --frozen --no-install-project --group docs
-      - name: Fetch brand CSS
-        run: |
-          curl -sL https://raw.githubusercontent.com/Project-Navi/brand/main/docs/stylesheets/navi.css \
-            -o docs/stylesheets/navi.css
       - name: Build site
         run: uv run zensical build
       - name: Strip internal docs from build

docs/index.md

@@ -4,8 +4,6 @@ hide:
   - toc
 ---
 
-<div class="hero-glow" markdown>
-
 # fd-formalization
 
 **Lean 4 + Mathlib formalization of \((u,v)\)-flower fractal dimension.**
@@ -15,8 +13,6 @@ Hub distance \(= u^g\) and log-ratio convergence to \(\frac{\log(u+v)}{\log u}\)
 [Get Started](getting-started/quickstart.md){ .md-button .md-button--primary }
 [Theorems](reference/theorems.md){ .md-button }
 
-</div>
-
 ---
 
 ## What it proves

docs/stylesheets/navi.css

@@ -207,28 +207,6 @@ body {
   color: #7eb8a8;
 }
 
-/* --- Hero glow (landing page only) --- */
-.md-content .hero-glow {
-  position: relative;
-}
-
-.md-content .hero-glow::before {
-  content: '';
-  position: absolute;
-  top: 0;
-  left: 50%;
-  transform: translateX(-50%);
-  width: 150%;
-  height: 400px;
-  background: radial-gradient(
-    ellipse at center top,
-    rgba(126, 184, 168, 0.08) 0%,
-    transparent 70%
-  );
-  pointer-events: none;
-  z-index: -1;
-}
-
 /* --- Primary button — inverted per brand guide --- */
 .md-typeset .md-button--primary {
   background: #e8e4de;