diff --git a/code/html/custom.css b/code/html/custom.css
index d65c559c..21604c6c 100644
--- a/code/html/custom.css
+++ b/code/html/custom.css
@@ -187,3 +187,6 @@ span.slider {
 .panel.block {
     display: block;
 }
+select {
+    width: 100%;
+}