Fix: Small css adaptation

src/components/NavbarHeader.vue

@@ -32,7 +32,7 @@
           /></b-nav-item>
           <b-nav-item-dropdown>
             <template #button-content>
-              <i-bi-circle-half class="toggle-theme" />
+              <i-bi-circle-half />
               <span class="d-lg-none ms-2">Toggle theme</span>
             </template>
             <b-dropdown-item-button
@@ -148,9 +148,6 @@ export default defineComponent({
   margin-top: -8px;
   margin-bottom: -8px !important;
 }
-.toggle-theme {
-  margin-bottom: 0.25rem;
-}
 .navbar a img.nfdi4ingLogo {
   border: 0px;
   object-position: 0%;