diff --git a/gps.css b/gps.css
new file mode 100644
index 0000000..bf871ef
--- /dev/null
+++ b/gps.css
@@ -0,0 +1,20 @@
+/*
+     * CSS definitions for GPS treasure hunter
+     */
+    body {background: #dfd;}
+    div#mymap {
+        margin: auto; width: 90vw; height: 60vh; background: gray;
+        border: 2px solid navy;
+    }
+    span#info {background: white; min-width: 20em;}
+    button {padding: 1ex 2em;}
+    button.running {background: #ebb;}
+    .hidden {display: none;}
+     
+    .XXleaflet-marker-icon {background: red;}
+    :root {--icon-bg-color: red; --rotation: 0.7rad;}
+     
+    #arrowicon {
+        xbackground: var(--icon-bg-color);
+        transform: rotate(var(--rotation));
+    }