diff --git a/sd-card/html/edit_reference.html b/sd-card/html/edit_reference.html
index bb12366c..110c4a85 100644
--- a/sd-card/html/edit_reference.html
+++ b/sd-card/html/edit_reference.html
@@ -49,6 +49,39 @@
width: 660px;
padding: 5px;
}
+
+ .tooltip {
+ position: relative;
+ display: inline-block;
+ }
+
+ .tooltip .tooltiptext {
+ visibility: hidden;
+ width: 600px;
+ background-color: #fcfcfc;
+
+ padding: 5px;
+ padding-bottom: 0;
+
+ border: solid black 2px;
+
+ /* Position the tooltip */
+ position: absolute;
+ z-index: 1;
+ top: 100%;
+ left: 100%;
+ margin-left: -600px;
+ }
+
+ .tooltip:hover .tooltiptext {
+ visibility: visible;
+ }
+
+ .tooltip-content {
+ width: calc(100% - 2px);
+ height: calc(100% - 2px);
+ padding: 1px;
+ }