reduce height of notification_widget by a few pixels

IPython/frontend/html/notebook/static/notebook/less/notificationwidget.less

@@ -1,6 +1,6
 .notification_widget{
-    padding: 6px 12px;
-    margin-top: 1px;
+    padding: 3px 12px;
+    margin: 4px;
     z-index: 10;
     border: 1px solid #ccc;
     border-radius: @corner_radius;

IPython/frontend/html/notebook/static/style/style.min.css

@@ -1499,7 +1499,7 pre,code,kbd,samp{white-space:pre-wrap;}
 p{margin-bottom:0;}
 .end_space{height:200px;}
 #notification_area{z-index:10;}
-.notification_widget{padding:6px 12px;margin-top:1px;z-index:10;border:1px solid #ccc;border-radius:4px;background:rgba(240, 240, 240, 0.5);}
+.notification_widget{padding:3px 12px;margin:4px;z-index:10;border:1px solid #ccc;border-radius:4px;background:rgba(240, 240, 240, 0.5);}
 div.output_area{padding:0px;page-break-inside:avoid;display:-webkit-box;-webkit-box-orient:horizontal;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:horizontal;-moz-box-align:stretch;display:box;box-orient:horizontal;box-align:stretch;}
 div.output_area pre{font-family:monospace;margin:0;padding:0;border:0;font-size:100%;vertical-align:baseline;color:black;background-color:transparent;-webkit-border-radius:0;-moz-border-radius:0;border-radius:0;line-height:inherit;}
 div.output_subarea{padding:0.44em 0.4em 0.4em 1px;margin-left:6px;-webkit-box-flex:1;-moz-box-flex:1;box-flex:1;}