Fix mobile menu backdrop, trim unreleased changelog

public-layout.css sets background: var(--bg-primary) on
.pub-navbar__nav in its mobile media query, and that rule lands
after this Astro <style is:global> in the bundle. A plain --open
selector ties on specificity (0,1,0) and loses on source order,
so the panel rendered whatever var(--bg-primary) computed to in
the marketing context (effectively transparent on iOS Safari).
Stack class selectors
(.pub-navbar .pub-navbar__nav.pub-navbar__nav--open, 0,3,0) so
this rule wins regardless of bundle order, with a solid #0C1133
fallback before the color-mix line.

Lighter blur(10) on mobile so older phones don't fight a heavy
filter (the filter cost scales roughly with the radius squared).
Take the navbar and sticky CTA to blur(10) on mobile too for a
consistent look. Desktop keeps blur(12). Also morph the hamburger
into a close icon when the panel opens.

Drop the unreleased ### Changed entry on the council master
prompt fetch (implementation detail that didn't belong in
user-facing release notes).

Author: michael-chipmates

CHANGELOG.md

@@ -8,10 +8,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ## [Unreleased]
 
-### Changed
-
-- **Council master prompts now load from the media CDN.** `services/council/generator.ts` fetches `council_advisory_master.json` and `council_debate_master.json` from `${mediaBaseUrl}/instructions/...` instead of a same-origin `/assets/instructions/...` path. Matches how figure-specific instructions already load. Removes the last authored-text leak from the self-host docker image.
-
 ### Added
 
 - **Marketing pages migrated to Astro for sub-second first paint.** Figure and theme detail pages, catalogs, about, and contact now ship as prerendered static HTML from the sibling `marketing/` Astro project. The hero, journey overview, ideas, and CTA paint immediately, so ad clickers landing on `/figures/<name>/` see the page within a few hundred milliseconds instead of a blank dark screen until the React bundle parses. React islands handle only the trailer audio button and council preview audio. Catalog and about/contact pages ship zero React JS. The React SPA at `/` and `/de/` continues to handle login + post-login app.

marketing/src/components/Navbar.astro

@@ -82,4 +82,50 @@ const isActive = (path: string) => currentPath === path || currentPath === path.
     -webkit-backdrop-filter: blur(12px);
     border-bottom: 1px solid color-mix(in srgb, var(--gold-primary) 16%, transparent);
   }
+
+  /* Background fix for the open mobile menu. public-layout.css sets
+     .pub-navbar__nav { background: var(--bg-primary, #151C47) } inside
+     its mobile media query, and that rule lands AFTER this Astro
+     <style is:global> in the bundled CSS. A plain .pub-navbar__nav--open
+     selector ties on specificity (0,1,0) and loses on source order,
+     leaving the panel painted with whatever var(--bg-primary) resolves
+     to in the marketing-page context (which on iOS Safari rendered
+     effectively transparent). Stack the class selectors so this rule
+     hits specificity 0,3,0 and wins regardless of bundle order, with
+     a solid #0C1133 declaration before the color-mix line so the
+     panel still has a real background if color-mix is unsupported or
+     the declaration is parsed as invalid. Lighter blur(10) on mobile
+     so older phones don't fight a heavy filter. */
+  @media (max-width: 640px) {
+    .pub-navbar,
+    .pub-cta--sticky {
+      backdrop-filter: blur(10px);
+      -webkit-backdrop-filter: blur(10px);
+    }
+
+    .pub-navbar .pub-navbar__nav.pub-navbar__nav--open {
+      background: #0C1133;
+      background: color-mix(in srgb, var(--bg-deep-space, #0C1133) 90%, transparent);
+      backdrop-filter: blur(10px);
+      -webkit-backdrop-filter: blur(10px);
+      border-top: 1px solid color-mix(in srgb, var(--gold-primary, #E6BC5C) 16%, transparent);
+      box-shadow: 0 16px 40px color-mix(in srgb, #000 45%, transparent);
+      padding-bottom: max(2rem, env(safe-area-inset-bottom));
+    }
+
+    /* Hamburger morphs into a close icon when the panel is open. */
+    .pub-navbar__burger-line {
+      transform-origin: center;
+      transition: transform 0.2s ease, opacity 0.16s ease;
+    }
+    .pub-navbar__burger[aria-expanded="true"] .pub-navbar__burger-line:nth-child(1) {
+      transform: translateY(7px) rotate(45deg);
+    }
+    .pub-navbar__burger[aria-expanded="true"] .pub-navbar__burger-line:nth-child(2) {
+      opacity: 0;
+    }
+    .pub-navbar__burger[aria-expanded="true"] .pub-navbar__burger-line:nth-child(3) {
+      transform: translateY(-7px) rotate(-45deg);
+    }
+  }
 </style>