feat: design system — ambient motion, spacing/elevation/surface tokens, right-rail TOC, footer links, DESIGN.md

src/pages/proposals.astro

@@ -10,7 +10,8 @@ import Base from '../layouts/Base.astro';
     </div>
   </section>
 
-  <section class="container page">
+  <section class="band--moon">
+    <div class="container page">
     <span class="badge-mock">Mock — no submission logic</span>
     <span class="badge-ext">Target: Proposal Handling System (APC team) integrated into the portal</span>
     <div class="panel panel--narrow">
@@ -45,5 +46,6 @@ import Base from '../layouts/Base.astro';
       <button class="btn" type="button">Submit proposal</button>
       <p class="notice">Demonstration mock — the form does not store any data.</p>
     </div>
+    </div>
   </section>
 </Base>