Index: src/wp-admin/css/media.css
===================================================================
--- src/wp-admin/css/media.css	(revision 29684)
+++ src/wp-admin/css/media.css	(working copy)
@@ -513,11 +513,6 @@
 	border: 4px dashed #bbb;
 }
 
-.media-frame.mode-grid .attachments,
-.media-frame.mode-select .attachments {
-	padding: 2px;
-}
-
 .media-frame.mode-select .attachments-browser.fixed .attachments {
 	position: relative;
 	top: 94px; /* prevent jumping up when the toolbar becomes fixed */
@@ -606,6 +601,10 @@
 	padding: 0;
 }
 
+.media-frame.mode-grid .attachments-browser .attachments {
+	padding: 2px;
+}
+
 .media-frame.mode-grid .attachments-browser .no-media {
 	color: #999;
 	font-size: 18px;
Index: src/wp-includes/css/media-views.css
===================================================================
--- src/wp-includes/css/media-views.css	(revision 29684)
+++ src/wp-includes/css/media-views.css	(working copy)
@@ -748,7 +748,6 @@
  */
 .attachments {
 	margin: 0;
-	padding: 8px;
 	-webkit-overflow-scrolling: touch;
 }
 
@@ -1038,6 +1037,10 @@
 	margin: 11px 0;
 }
 
+.attachments-browser .attachments {
+	padding: 2px 8px 8px;
+}
+
 .attachments-browser .attachments,
 .attachments-browser .uploader-inline {
 	position: absolute;
@@ -2520,7 +2523,7 @@
 }
 
 .attachments[data-columns="3"] .attachment {
-	width: 33.3%;
+	width: 33.33%;
 }
 
 .attachments[data-columns="4"] .attachment {
@@ -2532,11 +2535,11 @@
 }
 
 .attachments[data-columns="6"] .attachment {
-	width: 16.6%;
+	width: 16.66%;
 }
 
 .attachments[data-columns="7"] .attachment {
-	width: 14.2%;
+	width: 14.28%;
 }
 
 .attachments[data-columns="8"] .attachment {
@@ -2544,7 +2547,7 @@
 }
 
 .attachments[data-columns="9"] .attachment {
-	width: 11.1%;
+	width: 11.11%;
 }
 
 .attachments[data-columns="10"] .attachment {
@@ -2552,9 +2555,9 @@
 }
 
 .attachments[data-columns="11"] .attachment {
-	width: 9%;
+	width: 9.09%;
 }
 
 .attachments[data-columns="12"] .attachment {
-	width: 8.3%;
+	width: 8.33%;
 }