diff --git a/admin/index.html b/admin/index.html
index 8777b21..8caaf23 100644
--- a/admin/index.html
+++ b/admin/index.html
@@ -59,7 +59,7 @@
     :root{--sn-w:0}
     body{padding-bottom:64px}
     .sidenav{top:auto;bottom:0;left:0;right:0;width:100%;height:auto;
-         padding:4px;flex-direction:row;background:rgba(11,14,20,.52);
+         padding:4px;flex-direction:row;background:rgba(11,14,20,.94);backdrop-filter:blur(12px);
          display:flex;justify-content:space-around;overflow-x:auto;
          /* Hide horizontal scrollbar chrome; icons still swipe/scroll when they overflow. */
          scrollbar-width:none;-ms-overflow-style:none}
diff --git a/brand/index.html b/brand/index.html
index ee56c8b..af4c6be 100644
--- a/brand/index.html
+++ b/brand/index.html
@@ -64,7 +64,7 @@
     :root{--sn-w:0}
     body{padding-bottom:64px}
     .sidenav{top:auto;bottom:0;left:0;right:0;width:100%;height:auto;
-         padding:4px;flex-direction:row;background:rgba(11,14,20,.52);
+         padding:4px;flex-direction:row;background:rgba(11,14,20,.94);backdrop-filter:blur(12px);
          display:flex;justify-content:space-around;overflow-x:auto;
          /* Hide horizontal scrollbar chrome; icons still swipe/scroll when they overflow. */
          scrollbar-width:none;-ms-overflow-style:none}
diff --git a/docs/index.html b/docs/index.html
index ec89ac9..c150c9c 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -66,7 +66,7 @@
     :root{--sn-w:0}
     body{padding-bottom:64px}
     .sidenav{top:auto;bottom:0;left:0;right:0;width:100%;height:auto;
-         padding:4px;flex-direction:row;background:rgba(11,14,20,.52);
+         padding:4px;flex-direction:row;background:rgba(11,14,20,.94);backdrop-filter:blur(12px);
          display:flex;justify-content:space-around;overflow-x:auto;
          /* Hide the horizontal scrollbar chrome — the icons still scroll if
             they overflow, they just don't paint a green Windows scroll rail
diff --git a/index.html b/index.html
index 097acb0..833c60c 100644
--- a/index.html
+++ b/index.html
@@ -117,7 +117,7 @@
     :root{--sn-w:0}
     body{padding-bottom:64px}
     .sidenav{top:auto;bottom:0;left:0;right:0;width:100%;height:auto;
-         padding:4px;flex-direction:row;background:rgba(11,14,20,.52);
+         padding:4px;flex-direction:row;background:rgba(11,14,20,.94);backdrop-filter:blur(12px);
          display:flex;justify-content:space-around;overflow-x:auto;
          /* Hide horizontal scrollbar chrome; icons still swipe/scroll when they overflow. */
          scrollbar-width:none;-ms-overflow-style:none}
diff --git a/js/theme.js b/js/theme.js
index d835a1b..0832a80 100644
--- a/js/theme.js
+++ b/js/theme.js
@@ -1,104 +1,16 @@
-// Sirius.X font picker — reader chooses between Fraunces (Silent Mode
-// family — editorial serif, default) and Ubuntu (Bitcoin Cash brand
-// font — humanist sans). Persisted in localStorage under 'sirius-font'.
+// Sirius.X font — Ubuntu, always. The Fraunces/Ubuntu toggle was
+// removed 2026-09-22; readers on every page get the Bitcoin Cash brand
+// font without a picker in the corner. The runtime attribute goes on
+// <html> so the same `html[data-font-cmp="ubuntu"]` rules already
+// embedded in every page's stylesheet take effect on load.
 //
-// The runtime attribute goes on <html> — pages that want to opt out
-// simply omit the include. The actual font-swap CSS is defined per
-// page (in each page's <style> block) so it can override the page's
-// own font-family declarations at high specificity; this script only
-// toggles the attribute and paints the picker UI.
+// This file stays in place (rather than being deleted) so pages that
+// still reference it via <script src="js/theme.js"> keep loading a
+// valid module. Delete the include from a page and the attribute is
+// no longer set, and Fraunces returns.
 
 (function () {
-  var KEY = "sirius-font";
-  var saved = null;
-  try { saved = localStorage.getItem(KEY); } catch (e) { /* private mode */ }
-  var initial = saved === "ubuntu" ? "ubuntu" : "fraunces";
-  if (initial === "ubuntu") document.documentElement.setAttribute("data-font-cmp", "ubuntu");
-
-  // Inject the picker's own base + positioning styles once, so pages
-  // that never declared `.font-picker` in their stylesheet still render
-  // the widget correctly (previously the toggle appeared as raw browser
-  // buttons on pages that forgot to copy the CSS block). The styles are
-  // scoped to `.font-picker-float` so pages that DO define their own
-  // `.font-picker` styling win via source-order (this block runs first).
-  (function ensureStyles() {
-    if (document.getElementById("sirius-font-picker-style")) return;
-    var css =
-      // Every dimension is reset explicitly (bottom/left/height/width auto,
-      // margin 0, line-height 1) so this block wins over any per-page
-      // `.font-picker`/`.font-picker-float` styling — earlier pages declared
-      // .font-picker-float with bottom:20px, which combined with top:56px
-      // stretched the pill down the full viewport height.
-      ".font-picker-float{" +
-        "position:fixed !important;top:56px !important;right:20px !important;" +
-        "bottom:auto !important;left:auto !important;" +
-        "height:auto !important;width:auto !important;margin:0 !important;" +
-        "z-index:30 !important;" +
-        "display:inline-flex !important;align-items:center;gap:2px;padding:2px !important;" +
-        "background:rgba(11,14,20,.82) !important;border:1px solid rgba(255,255,255,.08) !important;" +
-        "border-radius:999px !important;backdrop-filter:blur(10px);" +
-        "box-shadow:0 6px 20px rgba(0,0,0,.35);" +
-        "font-family:'JetBrains Mono',ui-monospace,monospace !important;" +
-        "font-size:10px !important;line-height:1 !important;" +
-        "letter-spacing:.12em !important;text-transform:uppercase !important" +
-      "}" +
-      ".font-picker-float button{" +
-        "background:transparent !important;border:none !important;color:#6a7488 !important;" +
-        "padding:4px 10px !important;margin:0 !important;border-radius:999px !important;cursor:pointer;" +
-        "font-family:inherit !important;font-size:inherit !important;line-height:1 !important;" +
-        "letter-spacing:inherit !important;" +
-        "text-transform:inherit !important;transition:color .12s" +
-      "}" +
-      ".font-picker-float button:hover{color:#f1f4fa !important}" +
-      ".font-picker-float button.active{background:#d6ff3d !important;color:#050810 !important;font-weight:600 !important}" +
-      // On mobile the pill stays in the top-right — earlier it flipped to
-      // bottom-right so it wouldn't crowd narrow nav layouts, but the mobile
-      // sidenav now lives at the bottom edge and the two collided. Keep the
-      // toggle where readers already know to look; just tighten the offset a
-      // touch so it sits against the corner.
-      "@media (max-width:520px){.font-picker-float{top:12px !important;right:12px !important;bottom:auto !important}}";
-    var el = document.createElement("style");
-    el.id = "sirius-font-picker-style";
-    el.textContent = css;
-    document.head.appendChild(el);
-  })();
-
-  // Mount the picker as a floating pill in the page's top-right corner,
-  // just under the sticky nav's sign-in button. Was previously injected
-  // inline in the topnav; that placement crowded the nav on narrow
-  // viewports and left users hunting for the toggle. A fixed-position
-  // widget keeps the choice equally reachable on every page — including
-  // ones without a topnav — and does not participate in nav layout.
-  function paintPicker() {
-    var mount = document.createElement("div");
-    mount.className = "font-picker font-picker-float";
-    mount.setAttribute("role", "group");
-    mount.setAttribute("aria-label", "Reading font");
-    mount.innerHTML =
-      '<button data-font="fraunces" title="Silent Mode family (Fraunces)">Fraunces</button>' +
-      '<button data-font="ubuntu" title="Bitcoin Cash brand font (Ubuntu)">Ubuntu</button>';
-    document.body.appendChild(mount);
-    var btns = mount.querySelectorAll("button");
-    function refresh(v) {
-      for (var i = 0; i < btns.length; i++) {
-        btns[i].classList.toggle("active", btns[i].dataset.font === v);
-      }
-    }
-    refresh(initial);
-    for (var i = 0; i < btns.length; i++) {
-      btns[i].addEventListener("click", function (e) {
-        var v = e.currentTarget.dataset.font;
-        if (v === "ubuntu") document.documentElement.setAttribute("data-font-cmp", "ubuntu");
-        else document.documentElement.removeAttribute("data-font-cmp");
-        try { localStorage.setItem(KEY, v); } catch (e2) { /* ignore */ }
-        refresh(v);
-      });
-    }
-  }
-
-  if (document.readyState === "loading") {
-    document.addEventListener("DOMContentLoaded", paintPicker);
-  } else {
-    paintPicker();
-  }
+  try {
+    document.documentElement.setAttribute("data-font-cmp", "ubuntu");
+  } catch (e) { /* prehistoric browser; give up quietly */ }
 })();
diff --git a/theseus/index.html b/theseus/index.html
index 42c8dca..76dfac6 100644
--- a/theseus/index.html
+++ b/theseus/index.html
@@ -71,7 +71,7 @@
     :root{--sn-w:0}
     body{padding-bottom:64px}
     .sidenav{top:auto;bottom:0;left:0;right:0;width:100%;height:auto;
-         padding:4px;flex-direction:row;background:rgba(11,14,20,.52);
+         padding:4px;flex-direction:row;background:rgba(11,14,20,.94);backdrop-filter:blur(12px);
          display:flex;justify-content:space-around;overflow-x:auto;
          /* Hide horizontal scrollbar chrome; icons still swipe/scroll when they overflow. */
          scrollbar-width:none;-ms-overflow-style:none}
diff --git a/tld.html b/tld.html
index 65ac639..156f868 100644
--- a/tld.html
+++ b/tld.html
@@ -93,7 +93,7 @@
     :root{--sn-w:0}
     body{padding-bottom:64px}
     .sidenav{top:auto;bottom:0;left:0;right:0;width:100%;height:auto;
-         padding:4px;flex-direction:row;background:rgba(11,14,20,.52);
+         padding:4px;flex-direction:row;background:rgba(11,14,20,.94);backdrop-filter:blur(12px);
          display:flex;justify-content:space-around;overflow-x:auto;
          /* Hide horizontal scrollbar chrome; icons still swipe/scroll when they overflow. */
          scrollbar-width:none;-ms-overflow-style:none}
