fix theme issues

webapp/src/components/DFCode.vue

@@ -1,6 +1,6 @@
 <template>
   <div style="position: relative">
-    <v-btn @click="copyToClipboard" icon variant="plain" flat class="copy-button">
+    <v-btn color="white" @click="copyToClipboard" icon variant="plain" flat class="copy-button">
       <v-icon>mdi-content-copy</v-icon>
     </v-btn>
     <code ref="codeContent">

webapp/src/components/OSMTagSelector.vue

@@ -103,6 +103,7 @@ const selectedBrand: Ref<WikidataItem> = ref(alprBrands[0]);
 
 .overlay {
   text-shadow: 2px 2px 4px rgba(0, 0, 0, 1);
+  color: white;
   /* font-family: 'Courier New', Courier, monospace; */
   font-weight: bold;
   text-transform: uppercase;