diff --git a/css/custom.css b/css/custom.css
index 00e7250..ff286c2 100644
--- a/css/custom.css
+++ b/css/custom.css
@@ -12,3 +12,38 @@ table {
     margin-left: auto;
     margin-right: auto;
 }
+
+.org-src-container > pre.src:before {
+  display: inline;
+  position: absolute;
+  color: #808080;
+  background-color: white;
+  top: -10px;
+  left: 10px;
+  padding: 0px 4px;
+  border: 1px solid #d0d0d0;
+  font-size: 80%;
+}
+.org-src-container > pre {
+  margin-top: 1.5em;
+  position: relative;
+  overflow: visible;
+}
+.org-src-container > pre > code.src:before {
+  display: inline;
+  position: absolute;
+  color: #808080;
+  background-color: white;
+  top: -10px;
+  left: 10px;
+  padding: 0px 4px;
+  border: 1px solid #d0d0d0;
+  font-size: 80%;
+}
+.org-src-container > pre.src-emacs-lisp:before { content: 'Emacs Lisp'; }
+.org-src-container > pre.src-elisp:before { content: 'Emacs Lisp'; }
+.org-src-container > pre.src-sh:before { content: 'shell'; }
+.org-src-container > pre.src-bash:before { content: 'bash'; }
+.org-src-container > pre.src-org:before { content: 'Org mode'; }
+.org-src-container > pre.src-python:before { content: 'Python'; }
+.org-src-container > pre.src-matlab:before { content: 'Matlab'; }