fixed page-header-bg

public/sass/_variables.dark.scss

@@ -116,7 +116,7 @@ $panel-header-hover-bg: $dark-9;
 $panel-corner: $panel-bg;
 
 // page header
-$page-header-bg: linear-gradient(90deg, $dark-7, $input-black);
+$page-header-bg: linear-gradient(90deg, $dark-7, $black);
 $page-header-shadow: inset 0px -4px 14px $dark-3;
 $page-header-border-color: $dark-9;