✨ v3 theme: glass UI, landing layout, a11y, perf, print styles

Floating glass header with ⌘K search, landing homepage layout with
hero image and GitHub-stars CTA, background canvas with dissolving
heroes, burufugu colour scheme, movie-quote 404, taxonomy pills,
keyboard/ARIA accessibility across menus, search and tabs, idle-
loaded third-party scripts, and dedicated print styles.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

layouts/_default/baseof.html

@@ -39,18 +39,55 @@
         {{- partial "search.html" . -}}
       {{ end }}
     </div>
+    {{/* Rendered after the main block so page heroes that paint their own
+      fixed background can suppress the site-wide canvas for their page.
+      The layer is fixed, so its position in the DOM has no visual effect. */}}
+    {{ if and (site.Params.backgroundCanvas | default false) (not (.Store.Get "suppressBackgroundCanvas")) }}
+      {{ $default := site.Store.Get "defaultBackgroundImage" }}
+      {{ $canvasURL := $default.url }}
+      {{ if not $canvasURL }}
+        {{ with $default.obj }}{{ $canvasURL = .RelPermalink }}{{ end }}
+      {{ end }}
+      {{ with $canvasURL }}
+        <div id="background-canvas" aria-hidden="true" class="pointer-events-none fixed inset-0 -z-20">
+          <img
+            src="{{ . }}"
+            role="presentation"
+            loading="eager"
+            decoding="async"
+            class="nozoom h-full w-full object-cover" />
+          <div class="absolute inset-0 bg-neutral/75 dark:bg-neutral-800/60"></div>
+        </div>
+      {{ end }}
+    {{ end }}
   </body>
   {{ if site.Params.buymeacoffee.globalWidget | default false }}
-    <script
-      data-name="BMC-Widget"
-      data-cfasync="false"
-      src="https://cdnjs.buymeacoffee.com/1.0.0/widget.prod.min.js"
-      data-id="{{ site.Params.buymeacoffee.identifier }}"
-      data-description="Support me on Buy me a coffee!"
-      {{ with site.Params.buymeacoffee.globalWidgetMessage }}data-message="{{ . }}"{{ end }}
-      {{ with site.Params.buymeacoffee.globalWidgetColor | default `#FFDD00` }}data-color="{{ . }}"{{ end }}
-      {{ with site.Params.buymeacoffee.globalWidgetPosition }}data-position="{{ . }}"{{ end }}
-      data-x_margin="18"
-      data-y_margin="18"></script>
+    {{/* Inject the third-party widget after the page is idle so it never
+      competes with rendering-critical resources. */}}
+    <script>
+      (function () {
+        var load = function () {
+          var s = document.createElement("script");
+          s.src = "https://cdnjs.buymeacoffee.com/1.0.0/widget.prod.min.js";
+          s.setAttribute("data-name", "BMC-Widget");
+          s.setAttribute("data-cfasync", "false");
+          s.setAttribute("data-id", {{ site.Params.buymeacoffee.identifier }});
+          s.setAttribute("data-description", "Support me on Buy me a coffee!");
+          {{ with site.Params.buymeacoffee.globalWidgetMessage }}s.setAttribute("data-message", {{ . }});{{ end }}
+          s.setAttribute("data-color", {{ site.Params.buymeacoffee.globalWidgetColor | default `#FFDD00` }});
+          {{ with site.Params.buymeacoffee.globalWidgetPosition }}s.setAttribute("data-position", {{ . }});{{ end }}
+          s.setAttribute("data-x_margin", "18");
+          s.setAttribute("data-y_margin", "18");
+          document.body.appendChild(s);
+        };
+        if ("requestIdleCallback" in window) {
+          requestIdleCallback(load, { timeout: 4000 });
+        } else {
+          window.addEventListener("load", function () {
+            setTimeout(load, 1500);
+          });
+        }
+      })();
+    </script>
   {{ end }}
 </html>