diff --git a/style/shiny/single.css b/style/shiny/single.css
index 47c0b5d..1e16076 100644
--- a/style/shiny/single.css
+++ b/style/shiny/single.css
@@ -4,6 +4,7 @@
 
 :root {
   --image-width: 1000px;
+  --border-thickness: 2px;
 }
 
 body {
@@ -17,8 +18,6 @@ body {
 }
 
 #mainfig {
-  --border-thickness: 2px;
-
   margin: 1em auto;
   width: min-content;
   position: relative;