diff --git a/static/img/icons/muon.svg b/static/img/icons/muon.svg
index 5fed687e..43658e58 100644
--- a/static/img/icons/muon.svg
+++ b/static/img/icons/muon.svg
@@ -1,4 +1,8 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 230" width="100%" height="100%">
+  <style>
+    .shadow { stop-color: #000; }
+    @media (prefers-color-scheme: dark) { .shadow { stop-color: #fff; } }
+  </style>
   <defs>
     <linearGradient id="ball" x1="0" y1="0.25" x2="1" y2="0.75">
       <stop offset="0.1" stop-color="#0ef60e" />
@@ -11,10 +15,17 @@
       <stop offset="0.8" stop-color="#00ff9e" />
     </linearGradient>
     <radialGradient id="shadow">
-      <stop offset="0.6" stop-opacity="0.21" />
-      <stop offset="1" stop-opacity="0" />
+      <stop class="shadow" offset="0.6" stop-opacity="0.21" />
+      <stop class="shadow" offset="1" stop-opacity="0" />
+    </radialGradient>
+    <!-- off-centre, so the inset shadow spares the top-left rim -->
+    <radialGradient id="inset" cx="0.44" cy="0.42" r="0.58">
+      <stop offset="0.85" stop-opacity="0" />
+      <stop offset="1" stop-opacity="0.1" />
     </radialGradient>
   </defs>
   <circle cx="101.8" cy="46.4" r="34.8" fill="url(#ball)" stroke="#00e591" stroke-width="0.8" />
+  <!-- inset shadow, as in the old PNG logo -->
+  <circle cx="101.8" cy="46.4" r="34.8" fill="url(#inset)" />
   <ellipse cx="99.4" cy="210.4" rx="20.5" ry="14.5" fill="url(#shadow)" />
 </svg>