Edited the CSS of header and sidebar; added a new class of logo-container to the html to make things easier

app/assets/stylesheets/generic/header.scss

@@ -3,6 +3,8 @@
  *
  */
 header {
+  transition-duration: .3s;
+
   &.navbar-empty {
     background: #FFF;
     border-bottom: 1px solid #EEE;
@@ -63,28 +65,34 @@ header {
     float: left;
     height: $header-height;
     width: $sidebar_width;
+    transition-duration: .3s;
 
     a {
       float: left;
       height: $header-height;
       width: 100%;
       padding: ($header-height - 36 ) / 2 8px;
-
-      h3 {
-        width: 158px;
-        float: left;
-        margin: 0;
-        margin-left: 14px;
-        font-size: 18px;
-        line-height: $header-height - 14;
-        font-weight: normal;
-      }
+      overflow: hidden;
 
       img {
         width: 36px;
         height: 36px;
         float: left;
       }
+
+      .gitlab-text-container {
+        width: 230px;
+
+        h3 {
+          width: 158px;
+          float: left;
+          margin: 0;
+          margin-left: 14px;
+          font-size: 18px;
+          line-height: $header-height - 14;
+          font-weight: normal;
+        }
+      }
     }
 
     &:hover {

app/assets/stylesheets/generic/sidebar.scss

@@ -4,12 +4,14 @@
     top: 0;
     left: 0;
     height: 100%;
+    transition-duration: .3s;
   }
 }
 
 .sidebar-wrapper {
   z-index: 99;
   background: $background-color;
+  transition-duration: .3s;
 }
 
 .content-wrapper {
@@ -19,8 +21,10 @@
 }
 
 .nav-sidebar {
+  transition-duration: .3s;
   margin: 0;
   list-style: none;
+  overflow: hidden;
 
   &.navbar-collapse {
     padding: 0px !important;
@@ -34,9 +38,6 @@
   @include border-radius(6px);
 }
 
-.nav-sidebar li {
-}
-
 .nav-sidebar li {
   &.separate-item {
     padding-top: 10px;
@@ -79,6 +80,7 @@
 
 @mixin expanded-sidebar {
   padding-left: $sidebar_width;
+  transition-duration: .3s;
 
   .sidebar-wrapper {
     width: $sidebar_width;
@@ -89,6 +91,10 @@
       top: $header-height;
       width: $sidebar_width;
     }
+
+    .nav-sidebar li a{
+      width: 230px;
+    }
   }
 
   .content-wrapper {
@@ -98,6 +104,7 @@
 
 @mixin folded-sidebar {
   padding-left: 50px;
+  transition-duration: .3s;
 
   .sidebar-wrapper {
     width: $sidebar_collapsed_width;
@@ -112,7 +119,7 @@
         padding-left: 18px;
         font-size: 14px;
         padding: 8px 15px;
-        text-align: center;
+        text-align: left;
 
 
         & > span {
@@ -144,6 +151,7 @@
   height: 28px;
   text-align: center;
   line-height: 28px;
+  transition-duration: .3s;
 }
 
 .collapse-nav a:hover {
@@ -180,8 +188,10 @@
   bottom: 0;
   width: 100%;
   padding: 10px;
+  overflow: hidden;
 
   .username {
     margin-top: 5px;
+    width: 230px;
   }
 }

app/views/layouts/header/_default.html.haml

@@ -3,7 +3,8 @@
     .header-logo
       = link_to root_path, class: 'home', title: 'Dashboard', id: 'js-shortcuts-home', data: {toggle: 'tooltip', placement: 'bottom'} do
         = brand_header_logo
-        %h3 GitLab
+        .gitlab-text-container
+          %h3 GitLab
     .header-content
       %button.navbar-toggle{type: 'button'}
         %span.sr-only Toggle navigation

app/views/layouts/header/_public.html.haml

@@ -3,7 +3,8 @@
     .header-logo
       = link_to explore_root_path, class: "home" do
         = brand_header_logo
-        %h3 GitLab
+        .gitlab-text-container
+          %h3 GitLab
     .header-content
       - unless current_controller?('sessions')
         .pull-right