diff --git a/app/static/css/theme_modern.css b/app/static/css/theme_modern.css
index bf6fbc2..9649d55 100644
--- a/app/static/css/theme_modern.css
+++ b/app/static/css/theme_modern.css
@@ -220,23 +220,8 @@ body.jqc-modern {
 }
 .jqc-modern .jqc-nav-sublink:hover { background: var(--jqc-brand-025); color: var(--jqc-brand); }
 .jqc-modern .jqc-nav-sublink.active { color: var(--jqc-brand); font-weight: 700; }
-.jqc-modern .jqc-sidebar-foot {
-  flex: 0 0 auto;
-  padding: 14px 16px 20px;
-  border-top: 1px solid var(--jqc-border);
-}
-.jqc-modern .jqc-switch-btn {
-  width: 100%;
-  background: #fff;
-  border: 1.5px solid var(--jqc-brand);
-  color: var(--jqc-brand);
-  border-radius: 999px;
-  font-size: .82rem;
-  font-weight: 600;
-  padding: 8px 10px;
-  transition: background-color .15s, color .15s;
-}
-.jqc-modern .jqc-switch-btn:hover { background: var(--jqc-brand); color: #fff; }
+/* .jqc-sidebar-foot / .jqc-switch-btn were dropped in phase50 along with the
+   sidebar design switcher — no template references them any more. */
 .jqc-modern .jqc-sidebar-backdrop {
   position: fixed;
   inset: 0;
diff --git a/app/templates/layouts/modern.html b/app/templates/layouts/modern.html
index 57d94bb..ea5f6be 100644
--- a/app/templates/layouts/modern.html
+++ b/app/templates/layouts/modern.html
@@ -293,16 +293,10 @@
             </a>
         </nav>
 
-        <div class="jqc-sidebar-foot">
-            <form method="POST" action="{{ url_for('ui.switch_theme') }}">
-                <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
-                <input type="hidden" name="theme" value="classic">
-                <input type="hidden" name="next" value="{{ request.full_path }}">
-                <button type="submit" class="jqc-switch-btn" title="Switch back to the classic design">
-                    <i class="bi bi-arrow-left-right"></i> Classic Design
-                </button>
-            </form>
-        </div>
+        {# The design switcher was removed from the sidebar in phase50, when
+           modern became the default — it no longer belongs in the primary nav.
+           The same action still exists in the account menu (top right), so
+           anyone who needs the classic design can still get to it. #}
     </aside>
     <div class="jqc-sidebar-backdrop d-lg-none" id="jqcSidebarBackdrop"></div>
     {% endif %}