Index: src/wp-admin/css/customize-controls.css
===================================================================
--- src/wp-admin/css/customize-controls.css	(revision 51701)
+++ src/wp-admin/css/customize-controls.css	(working copy)
@@ -2818,6 +2818,10 @@
 		margin-top: 12px;
 	}
 
+	.themes-filter-bar .search-icon {
+		top: 12px;
+	}
+
 	.wp-core-ui .themes-filter-bar .feature-filter-toggle {
 		margin: 3px 0 3px 25px;
 	}
@@ -2896,6 +2900,11 @@
 		display: block;
 	}
 
+	.preview-only #customize-preview {
+		margin-top: 46px;
+		height: calc(100% - 46px);
+	}
+
 	.wp-core-ui.wp-customizer .button {
 		min-height: 30px;
 		padding: 0 14px;
@@ -2968,10 +2977,6 @@
 	.reordering .reorder-done {
 		padding: 8px;
 	}
-
-	.wp-core-ui .themes-filter-bar .feature-filter-toggle {
-		margin: 0;
-	}
 }
 
 @media screen and (max-width: 600px) {