Speed up animation transition; add hover state to top right icons

Remove subscribe text from button

app/assets/stylesheets/framework/header.scss

@@ -71,7 +71,7 @@ header {
         &:focus,
         &:active {
           background-color: $gray-light;
-          color: darken($gl-text-color-secondary, 30%);
+          color: $gl-text-color;
           .todos-pending-count {
             background: darken($todo-alert-blue, 10%);

app/assets/stylesheets/framework/variables.scss

@@ -178,7 +178,7 @@ $count-arrow-border: #dce0e5;
 $save-project-loader-color: #555;
 $divergence-graph-bar-bg: #ccc;
 $divergence-graph-separator-bg: #ccc;
-$general-hover-transition-duration: 150ms;
+$general-hover-transition-duration: 100ms;
 $general-hover-transition-curve: linear;

app/views/projects/issues/index.html.haml

@@ -19,10 +19,8 @@
       = render 'shared/issuable/nav', type: :issues
       .nav-controls
         - if current_user
-          = link_to url_for(params.merge(format: :atom, private_token: current_user.private_token)), class: 'btn append-right-10' do
+          = link_to url_for(params.merge(format: :atom, private_token: current_user.private_token)), class: 'btn append-right-10', title: 'Subscribe' do
             = icon('rss')
-            %span.icon-label
-              Subscribe
         - if can? current_user, :create_issue, @project
           = link_to new_namespace_project_issue_path(@project.namespace,
                                                      @project,