Hide shortcut key on Android.

src/components/HeaderControls.vue

@@ -211,6 +211,9 @@ onBeforeUnmount(() => {
   gap: 1rem;
 }
 
+@media (max-width: 600px) {
+  .header-controls { gap: 0.1rem; }
+}
 /* Group search + spacer so outer gap doesn't create unwanted space */
 .search-with-spacer {
   display: flex;

src/components/Search.vue

@@ -63,7 +63,9 @@ const searchIndex = ref(0)
 const searchInputRef = ref(null)
 let previewTimer = null
 
-const shortcut = /Mac/.test(navigator.userAgent) ? '⌘F'
+// Note: Android is also Linux. HarmonyOS 5 doesn't include "Linux".
+const shortcut = /Android/.test(navigator.userAgent) ? ''
+  : /Mac/.test(navigator.userAgent) ? '⌘F'
   : /Windows|Linux/.test(navigator.userAgent) ? 'Ctrl+F'
   : ''