diff --git a/src/components/Layout/Header.less b/src/components/Layout/Header.less
index a308f32..1709b6d 100644
--- a/src/components/Layout/Header.less
+++ b/src/components/Layout/Header.less
@@ -16,7 +16,7 @@
     top: 0;
     right: 0;
     width: ~'calc(100% - 256px)';
-    z-index: 9;
+    z-index: 29;
     transition: width 0.2s;
 
     &.collapsed {