Add explanation split infinitive

src/components/Header.vue

@@ -7,19 +7,19 @@
     <span class="header_group_list" v-if="group_list.length" tabindex="0">{{group_list}}</span>
 
     <span v-if="split_inf" tabindex="0"> (kløyvd infinitiv: <i>-a</i>
-      <v-menu rounded="lg" v-model="menu" offset-x max-width="200px">
+      <v-menu rounded="0" v-model="menu" offset-x max-width="200px">
         <template v-slot:activator="{ on, attrs }">
           <v-btn v-bind="attrs" v-on="on" depressed min-width="14px" max-width="14px" class="help-button" x-small
             color="primary">
             <v-icon middle x-small>$vuetify.icons.value.info</v-icon>
           </v-btn>
         </template>
-        <v-card class="info-card">
+        <v-card rounded="0" class="info-card">
           Dersom du bruker kløyvd infinitiv, skal dette verbet ha <i>-a</i> i infinitiv. Les meir
           <a target="_blank" href="https://www.sprakradet.no/svardatabase/sporsmal-og-svar/kloyvd-infinitiv-/">her</a>.
         </v-card>
-      </v-menu>
-    </span>)
+      </v-menu>)
+    </span>
 
     <details :title="inflect_tooltip" @toggle="toggle()" v-if="inflected" :class="$vuetify.breakpoint.name">
       <summary :class="dictionary" onclick="this.blur()" tabindex="0">bøying</summary>
@@ -145,7 +145,6 @@ article h2.secondary_header {
 
 .info-card {
   padding: 12px;
-  
 }
 
 .word-classification {