diff --git a/app/assets/stylesheets/common/base/_topic-list.scss b/app/assets/stylesheets/common/base/_topic-list.scss
index 1b190f4e33f..addd06fe53d 100644
--- a/app/assets/stylesheets/common/base/_topic-list.scss
+++ b/app/assets/stylesheets/common/base/_topic-list.scss
@@ -192,44 +192,6 @@
   color: #9b764f !important;
 }
 
-.topic-list.categories {
-  .category .badge-notification {
-    background-color: transparent;
-    color: $primary-medium;
-  }
-
-  .subcategories .badge {
-    display: none;
-  }
-
-  td.category {
-    vertical-align: top;
-    padding-top: 15px;
-    padding-bottom: 15px;
-    border-left: 6px solid;
-  }
-  td.stats {
-    .unit {
-      font-size: $font-down-1;
-    }
-  }
-
-  table.categoryStats {
-    td {
-      padding: 2px;
-      vertical-align: bottom;
-      line-height: $line-height-large;
-      &.value {
-        text-align: right;
-        font-size: $font-up-3;
-      }
-      &.unit {
-        text-align: left;
-      }
-    }
-  }
-}
-
 .loading .topic-list {
   border: 0;
   box-shadow: none;
diff --git a/app/assets/stylesheets/common/base/user-badges.scss b/app/assets/stylesheets/common/base/user-badges.scss
index 63c87e270d7..22d961b193d 100644
--- a/app/assets/stylesheets/common/base/user-badges.scss
+++ b/app/assets/stylesheets/common/base/user-badges.scss
@@ -225,7 +225,7 @@
     &:active {
       box-shadow: none;
     }
-    @media all and (max-width: 320px) {
+    @include mobile-portrait {
       width: 100%;
     }
   }
diff --git a/app/assets/stylesheets/common/foundation/mixins.scss b/app/assets/stylesheets/common/foundation/mixins.scss
index a6a3ed9bb8a..f7050f524c1 100644
--- a/app/assets/stylesheets/common/foundation/mixins.scss
+++ b/app/assets/stylesheets/common/foundation/mixins.scss
@@ -28,26 +28,6 @@
     @content;
   }
 }
-@mixin not-mobile-portrait {
-  @media all and (min-width: 321px) {
-    @content;
-  }
-}
-@mixin mobile-landscape {
-  @media all and (min-width: 321px) and (max-width: 959px) {
-    @content;
-  }
-}
-@mixin not-tablet-landscape {
-  @media all and (max-width: 959px) {
-    @content;
-  }
-}
-@mixin tablet-landscape {
-  @media all and (min-width: 960px) {
-    @content;
-  }
-}
 
 // CSS3 properties
 // --------------------------------------------------
diff --git a/app/assets/stylesheets/common/topic-timeline.scss b/app/assets/stylesheets/common/topic-timeline.scss
index c6ef4a95db2..0f770e10469 100644
--- a/app/assets/stylesheets/common/topic-timeline.scss
+++ b/app/assets/stylesheets/common/topic-timeline.scss
@@ -7,7 +7,7 @@
   z-index: z("timeline");
   margin-left: 757px;
 
-  @media all and (min-width: 1140px) {
+  @include large-width {
     margin-left: 820px;
   }
   @media all and (min-width: 1250px) {
diff --git a/app/assets/stylesheets/desktop/topic-list.scss b/app/assets/stylesheets/desktop/topic-list.scss
index d94cfa62785..45f86443e96 100644
--- a/app/assets/stylesheets/desktop/topic-list.scss
+++ b/app/assets/stylesheets/desktop/topic-list.scss
@@ -160,70 +160,6 @@
   }
 }
 
-.topic-list.categories {
-  a.title {
-    color: $tertiary;
-  }
-
-  th.posts {
-    position: relative;
-  }
-  th.stats {
-    width: 90px;
-  }
-  td.latest {
-    vertical-align: top;
-    padding: 0 8px 8px;
-  }
-  .last-user-info {
-    font-size: $font-down-1;
-  }
-  .has-description {
-    td.category {
-      padding-top: 15px;
-    }
-  }
-  .category {
-    h3 {
-      display: inline-block;
-      font-size: $font-up-2;
-      i {
-        margin-right: 5px;
-      }
-      a[href] {
-        color: $primary;
-      }
-    }
-    .subcategories {
-      margin-top: 10px;
-    }
-    .category-description {
-      margin-top: 10px;
-    }
-    .clear-badge {
-      color: $primary;
-    }
-  }
-
-  .featured-topic {
-    margin: 10px 0 0;
-    /* topic status glyphs */
-    i {
-      color: dark-light-choose($primary-medium, $secondary-medium) !important;
-      font-size: 0.929em;
-    }
-    a.last-posted-at,
-    a.last-posted-at:visited {
-      color: dark-light-choose($primary-medium, $secondary-medium);
-      font-size: $font-down-1;
-    }
-    .badge {
-      font-size: $font-down-1;
-      top: -1px;
-    }
-  }
-}
-
 .topic-list-bottom {
   margin: 20px 0;
 }
@@ -293,7 +229,7 @@ button.dismiss-read {
 
 /* Tablet (portrait) ----------- */
 
-@media all and (max-width: 850px) {
+@include small-width {
   // slightly smaller font, tighten spacing on nav pills
   .nav-pills {
     > li > a {
diff --git a/app/assets/stylesheets/mobile/header.scss b/app/assets/stylesheets/mobile/header.scss
index dfc21d816a0..3b392e1768a 100644
--- a/app/assets/stylesheets/mobile/header.scss
+++ b/app/assets/stylesheets/mobile/header.scss
@@ -5,7 +5,7 @@
 #site-text-logo {
   font-size: $font-up-3;
 }
-@media only screen and (max-width: 320px) {
+@include mobile-portrait {
   #site-text-logo {
     font-size: $font-up-2;
   }
diff --git a/app/assets/stylesheets/mobile/topic-list.scss b/app/assets/stylesheets/mobile/topic-list.scss
index 07063c59bf0..dbfde97c8bc 100644
--- a/app/assets/stylesheets/mobile/topic-list.scss
+++ b/app/assets/stylesheets/mobile/topic-list.scss
@@ -256,54 +256,6 @@ tr.category-topic-link {
   }
 }
 
-.topic-list.categories {
-  td.latest {
-    vertical-align: top;
-    padding: 5px;
-  }
-
-  .badge-category {
-    display: inline-block;
-    margin-top: 1px;
-  }
-  .featured-users {
-    @include mobile-portrait {
-      margin-bottom: 10px;
-      padding-top: 8px;
-      clear: left;
-    }
-    @include not-mobile-portrait {
-      float: right;
-    }
-  }
-  .latest {
-    @include mobile-portrait {
-      width: 150px;
-    }
-    @include mobile-landscape {
-      width: 270px;
-    }
-    @include tablet-landscape {
-      width: 450px;
-    }
-    .featured-topic {
-      margin: 8px 0;
-      a.last-posted-at,
-      a.last-posted-at:visited {
-        color: dark-light-choose($primary-medium, $secondary-medium);
-      }
-    }
-  }
-  .stats {
-    @include not-tablet-landscape {
-      display: none;
-    }
-    @include tablet-landscape {
-      min-width: 80px;
-    }
-  }
-}
-
 .category-list-item {
   padding: 5px 0 2px;
   border-left: 6px solid;