diff --git a/css/deepness.css b/css/deepness.css
new file mode 100644
index 0000000..3059452
--- /dev/null
+++ b/css/deepness.css
@@ -0,0 +1,57 @@
+/*
+ +-------------------------------------------------------------------------+
+ | Copyright (C) 2004-2026 The Cacti Group                                 |
+ |                                                                         |
+ | This program is free software; you can redistribute it and/or           |
+ | modify it under the terms of the GNU General Public License             |
+ | as published by the Free Software Foundation; either version 2          |
+ | of the License, or (at your option) any later version.                  |
+ |                                                                         |
+ | This program is distributed in the hope that it will be useful,         |
+ | but WITHOUT ANY WARRANTY; without even the implied warranty of          |
+ | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           |
+ | GNU General Public License for more details.                            |
+ +-------------------------------------------------------------------------+
+ | Cacti: The Complete RRDtool-based Graphing Solution                     |
+ +-------------------------------------------------------------------------+
+ | This code is designed, written, and maintained by the Cacti Group. See  |
+ | about.php and/or the AUTHORS file for specific developer information.   |
+ +-------------------------------------------------------------------------+
+ | http://www.cacti.net/                                                   |
+ +-------------------------------------------------------------------------+
+*/
+
+/*
+ * Deepness theme. The severity colour is applied as a low opacity tint so the dark
+ * page background shows through, and the text is kept light so every cell stays
+ * readable while still signalling severity.
+ */
+.servcheck_error {
+	background-color: rgba(242, 25, 36, 0.38);
+	color: #ffffff;
+}
+
+.servcheck_warning {
+	background-color: rgba(255, 122, 48, 0.34);
+	color: #ffffff;
+}
+
+.servcheck_failing {
+	background-color: rgba(250, 253, 158, 0.26);
+	color: #ffffff;
+}
+
+.servcheck_duration {
+	background-color: rgba(90, 190, 225, 0.30);
+	color: #ffffff;
+}
+
+.servcheck_ok {
+	background-color: rgba(24, 185, 129, 0.32);
+	color: #ffffff;
+}
+
+.servcheck_disabled {
+	background-color: rgba(161, 161, 161, 0.24);
+	color: #e6e6e6;
+}