Auth UI: reliably hide navbar on login via body_class; add .auth-logo sized ~button width; restart

static/css/custom.css

@@ -7,6 +7,9 @@ body {
     font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
 }
 
+/* Hide navbar for login page */
+.login-page .navbar { display: none; }
+
 /* Avoid overriding Bootstrap's global .container layout.
    Provide a scoped helper for auth pages instead. */
 .auth-wrapper {
@@ -36,6 +39,10 @@ body {
     box-shadow: none;
 }
 
+/* Auth logo scales close to button width */
+.auth-logo { max-width: 320px; }
+.auth-logo img { width: 100%; height: auto; object-fit: contain; }
+
 /* Input group styling */
 .input-group-lg .form-control {
     border-radius: 8px !important;