diff --git a/css/oressource.css b/css/oressource.css
index ca83aa8d..747df5c5 100644
--- a/css/oressource.css
+++ b/css/oressource.css
@@ -14,6 +14,24 @@ textarea {
   resize:none;
 }
 
+/* Accessibility */
+tbody tr td:first-child {
+  position: relative;
+}
+
+tbody tr td:first-child::before {
+  content: '';
+  inset: 0;
+  left: -1em;
+  position: absolute;
+  border-left: 1em solid transparent;
+  border-radius: 3px;
+}
+
+tbody tr:hover td:first-child::before {
+  border-color: initial;
+}
+
 /* Style for valid or Invalid form entry */
 input:invalid {
   border: 1px solid red;