alexnodeland
diff --git a/‎docs/book.toml‎
Lines changed: 3 additions & 2 deletions b/‎docs/book.toml‎
Lines changed: 3 additions & 2 deletions
diff --git a/‎docs/fugue-brand.js‎
Lines changed: 49 additions & 0 deletions b/‎docs/fugue-brand.js‎
Lines changed: 49 additions & 0 deletions
@@ -1,5 +1,5 @@
 [book]
-title = "Fugue-Evo Documentation"
+title = "Fugue Evo Docs"
 authors = ["Fugue-Evo Contributors"]
 language = "en"
 src = "src"
@@ -14,8 +14,9 @@ preferred-dark-theme = "navy"
 git-repository-url = "https://github.com/alexnodeland/fugue-evo"
 edit-url-template = "https://github.com/alexnodeland/fugue-evo/edit/main/docs/{path}"
 site-url = "https://evo.fugue.run/"
-additional-css = ["fugue-viz.css"]
+additional-css = ["fugue-theme.css", "fugue-viz.css"]
 additional-js = [
+    "fugue-brand.js",
     "fugue-viz.js",
     "fugue-evo-wasm-loader.js",
     "viz/landscape.js",
 
@@ -0,0 +1,49 @@
+/* fugue-brand.js — shared between fugue and fugue-evo (keep byte-identical).
+ *
+ * Injects a sibling-site link into the menu bar so fugue.run and
+ * evo.fugue.run point at each other. Which site we're on is detected by
+ * hostname; local previews can force it with
+ * <html data-fugue-site="fugue"|"evo">. */
+(function () {
+    'use strict';
+
+    function siblingFor(site) {
+        return site === 'evo'
+            ? { label: 'Fugue', href: 'https://fugue.run', title: 'Fugue — probabilistic programming for Rust' }
+            : { label: 'Evo', href: 'https://evo.fugue.run', title: 'Fugue Evo — evolutionary computation for Rust' };
+    }
+
+    function detectSite() {
+        var forced = document.documentElement.getAttribute('data-fugue-site');
+        if (forced === 'fugue' || forced === 'evo') return forced;
+        if (window.location.hostname.indexOf('evo.') === 0) return 'evo';
+        // Local preview fallback: the evo book titles itself "Fugue-Evo …".
+        if (/evo/i.test(document.title)) return 'evo';
+        return 'fugue';
+    }
+
+    function inject() {
+        var buttons = document.querySelector('#menu-bar .right-buttons');
+        if (!buttons || buttons.querySelector('.fugue-brand-link')) return;
+        var sib = siblingFor(detectSite());
+        var a = document.createElement('a');
+        a.className = 'fugue-brand-link';
+        a.href = sib.href;
+        a.title = sib.title;
+        a.setAttribute('aria-label', sib.title);
+        var label = document.createElement('span');
+        label.textContent = sib.label;
+        var arrow = document.createElement('span');
+        arrow.className = 'fugue-brand-arrow';
+        arrow.textContent = '↗';
+        a.appendChild(label);
+        a.appendChild(arrow);
+        buttons.insertBefore(a, buttons.firstChild);
+    }
+
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', inject);
+    } else {
+        inject();
+    }
+})();