diff -uNrp a/data/anaconda-gtk.css b/data/anaconda-gtk.css
--- a/data/anaconda-gtk.css	2019-08-21 18:50:27.188000000 +0800
+++ b/data/anaconda-gtk.css	2019-08-21 18:52:23.172000000 +0800
@@ -112,7 +112,8 @@ levelbar.discrete trough block.filled.hi
 AnacondaSpokeWindow #nav-box {
     background-color: @fedora;
     background-image: url('/usr/share/anaconda/pixmaps/topbar-bg.png');
-    background-repeat: repeat;
+    background-repeat: no-repeat;
+    background-size: 100% 100%;
     color: white;
 }