copy nav fix from application theme

app/javascript/styles/etr.scss

@@ -24,3 +24,31 @@
 @import 'mastodon/rtl';
 @import 'mastodon/accessibility';
 @import 'mastodon/rich_text';
+
+// The following "fixes" the mobile layout
+// in conjunction with the edits in `features/ui/components/header.jsx`
+// NOTE: $no-gap-breakpoint is when the UI becomes 3 columns
+.navigation-panel__logo,
+.ui__header__logo {
+  display: none;
+}
+@media screen and (max-width: $no-gap-breakpoint) {
+  .columns-area__panels__pane--navigational,
+  .navigation-panel__sign-in-banner,
+  .navigation-panel__legal > hr,
+  .column-link > span {
+    display: none;
+  }
+
+  .navigation-panel {
+    flex-direction: row;
+  }
+
+  .ui__header__links {
+    flex-shrink: unset;
+  }
+
+  .ui__header {
+    justify-content: center;
+  }
+}