diff --git a/core/modules/system/css/system.module.css b/core/modules/system/css/system.module.css
index a74934f..dc4a0d0 100644
--- a/core/modules/system/css/system.module.css
+++ b/core/modules/system/css/system.module.css
@@ -206,7 +206,8 @@ table.sticky-header {
 .progress__bar {
   background-color: #000;
   height: 1.5em;
-  width: 3%;
+  min-width: 3%;
+  max-width: 100%;
 }
 .progress__description,
 .progress__percentage {