core-dropdown updates, new demo

Author: Yvonne Yip

core-menu-button.css

@@ -7,4 +7,12 @@ license that can be found in the LICENSE file.
 :host {
   position: relative;
   display: inline-block;
+}
+
+#dropdown {
+  margin: 12px;
+  background: #fff;
+  color: #000;
+  border-radius: 3px;
+  border: 1px solid #ccc;
 }

core-menu-button.html

@@ -38,7 +38,7 @@
     <link rel="stylesheet" href="core-menu-button.css">
     <core-icon-button id="button" on-tap="{{toggle}}" src="{{src}}" icon="{{icon}}" active="{{opened}}"><span>{{label}}</span></core-icon-button>
     <core-dropdown id="dropdown" relatedTarget="{{$.button}}" opened="{{opened}}" halign="{{halign}}" valign="{{valign}}">
-      <core-menu selected="{{selected}}" selectedItem="{{selectedItem}}" selectedClass="{{selectedClass}}" valueattr="{{valueattr}}" on-core-select="{{closeAction}}">
+      <core-menu selected="{{selected}}" selectedItem="{{selectedItem}}" selectedClass="{{selectedClass}}" valueattr="{{valueattr}}" on-core-activate="{{closeAction}}">
         <content select="*"></content>
       </core-menu>
     </core-dropdown>
@@ -84,14 +84,14 @@
          * @attribute halign
          * @type string
          */
-        halign: 'auto',
+        halign: 'left',
 
         /**
          * Display the overlay on top or below the button.
          * @attribute valign
          * @type string
          */
-        valign: 'auto'
+        valign: 'top'
 
       },