UX: minor share report popup improvements (#49)

assets/javascripts/discourse/templates/components/share-report.hbs

@@ -5,9 +5,7 @@
 {{#if visible}}
   <div class='popup'>
     <label>{{i18n "explorer.link"}} {{group}}</label>
-    <input value={{link}}/>
-    <span onclick={{action "close"}}>
-      {{d-icon "times"}}
-    </span>
+    <input type="text" value={{link}}/>
+    {{d-button action="close" class="btn-flat close" icon="times" aria-label="share.close" title="share.close"}}
   </div>
 {{/if}}

assets/stylesheets/explorer.scss

@@ -413,7 +413,7 @@ table.group-reports {
     margin-right: 4px;
   }
   .popup {
-    background: white;
+    background-color: $secondary;
     position: absolute;
     box-shadow: shadow("card");
     padding: 12px;