refactor header buttons className

resource/css/_page.scss

@@ -110,10 +110,10 @@
       }
 
       // change button opacity
-      .btn {
+      .btn.btn-muted {
         opacity: 0.3;
       }
-      &:hover .btn {
+      &:hover .btn.btn-muted {
         opacity: unset;
       }
     }

resource/js/components/Page/RevisionPath.js

@@ -107,8 +107,8 @@ export default class RevisionPath extends React.Component {
         </span>
         {afterElements}
         <CopyButton buttonId="btnCopyRevisionPath" text={this.props.pagePath}
-            buttonClassName="btn btn-default" iconClassName="fa fa-clone text-muted" />
-        <a href="#edit-form" className="btn btn-default" style={editButtonStyle}>
+            buttonClassName="btn btn-default btn-muted" iconClassName="fa fa-clone text-muted" />
+        <a href="#edit-form" className="btn btn-default btn-muted" style={editButtonStyle}>
           <i className="fa fa-edit text-muted"></i>
         </a>
       </span>

resource/js/components/Page/RevisionUrl.js

@@ -24,7 +24,7 @@ export default class RevisionUrl extends React.Component {
       <span>
         {url}
         <CopyButton buttonId="btnCopyRevisionUrl" text={copiedText}
-            buttonClassName="btn btn-default" buttonStyle={buttonStyle} iconClassName="fa fa-link text-muted" />
+            buttonClassName="btn btn-default btn-muted" buttonStyle={buttonStyle} iconClassName="fa fa-link text-muted" />
       </span>
     );
   }