diff --git a/internal/smtp/gui.html b/internal/smtp/gui.html
index 5806933..aa60726 100644
--- a/internal/smtp/gui.html
+++ b/internal/smtp/gui.html
@@ -15,6 +15,10 @@
 .subject-hdr { width: 100%; }
 pre { background-color: #eee; padding: 10px; box-sizing: border-box; width: 100%; overflow-x: auto; }
 main > h4:first-of-type { padding-top: 0; margin-top: 0; }
+
+@media screen and (max-width: 1900px) {
+    .container { flex-direction: column; }
+}
 </style>
 
 </head>