style: change in ExportButton style (#6147) (#6148)

Co-authored-by: David Luzar <luzar.david@gmail.com>

src/components/ExportDialog.scss

@@ -96,6 +96,10 @@
     width: 5rem;
     height: 5rem;
     margin: 0 0.2em;
+    padding: 0;
+    display: flex;
+    align-items: center;
+    justify-content: center;
 
     border-radius: 1rem;
     background-color: var(--button-color);