diff --git a/web/src/css/custom.css b/web/src/css/custom.css
index f008a1719f4..19a76cddda8 100755
--- a/web/src/css/custom.css
+++ b/web/src/css/custom.css
@@ -1364,3 +1364,8 @@ details summary:hover {
 .admonition.admonition-caution .admonition-heading h5 {
   color: var(--custom-color-orange-800) !important;
 }
+
+.theme-back-to-top-button {
+  width: 2.5rem !important;
+  height: 2.5rem !important;
+}