Search bar: set full width on mobile

front/src/NavBarSearch.vue

@@ -33,7 +33,7 @@
 <template>
   <div class="navbar-item">
     <div class="field has-addons">
-      <div class="control">
+      <div class="control" :class="isMobile ? 'fullwidth' : ''">
         <input v-mobile-focus="isMobile ? true : null" v-model="searchterm" @keyup.enter="onSearchClick()" class="input" :class="sizeClass" type="text" />
       </div>
       <div class="control">
@@ -48,4 +48,8 @@
   </div>
 </template>
 
-<style scoped></style>
+<style scoped>
+  .fullwidth {
+    width: 100%;
+  }
+</style>