Index: wp-admin/css/common.css
===================================================================
--- wp-admin/css/common.css	(revision 40330)
+++ wp-admin/css/common.css	(working copy)
@@ -1335,6 +1335,11 @@
 		position: relative;
 		max-width: 100%;
 	}
+
+	.wp-filter .search-form input[type="search"] {
+		width: 100%;
+		display: inline-block;
+	}
 }
 
 @media only screen and (max-width: 782px) {
@@ -2210,6 +2215,10 @@
 	color: #000;
 }
 
+.nav-tab-active:hover {
+	border-bottom: 1px solid #ccc;
+}
+
 h1.nav-tab-wrapper, /* Back-compat for pre-4.4 */
 .wrap h2.nav-tab-wrapper, /* higher specificity to override .wrap > h2:first-child */
 .nav-tab-wrapper {