diff --git a/app/assets/stylesheets/common/admin/admin_base.scss b/app/assets/stylesheets/common/admin/admin_base.scss
index 11650c5f98a..0039b3248b9 100644
--- a/app/assets/stylesheets/common/admin/admin_base.scss
+++ b/app/assets/stylesheets/common/admin/admin_base.scss
@@ -20,7 +20,7 @@ td.flaggers td {
 }
 
 .content-list li a span.count {
-  font-size: 12px;
+  font-size: 0.857em;
   float: right;
   margin-right: 10px;
   background-color: scale-color-diff();
@@ -119,7 +119,7 @@ td.flaggers td {
     }
   }
   h1 {
-    font-size: 20px;
+    font-size: 1.429em;
     line-height: 25px;
     color: $primary;
   }
@@ -261,7 +261,7 @@ td.flaggers td {
     }
 
     h3 {
-      font-size: 13px;
+      font-size: 0.929em;
       font-weight: normal;
     }
   }
@@ -280,7 +280,7 @@ td.flaggers td {
 
 section.details {
   h1 {
-    font-size: 18px;
+    font-size: 1.286em;
     color: $primary;
     padding: 5px 10px;
     margin: 30px 0 5px 0;
@@ -339,7 +339,7 @@ section.details {
     width: 800px;
     float: left;
     margin-left: 12px;
-    font-size: 13px;
+    font-size: 0.929em;
 
     button {
       margin-left: 10px;
@@ -431,14 +431,14 @@ section.details {
   }
 
   .badge-errors {
-    font-size: 14px;
+    font-size: 1em;
     line-height: 16px;
     padding: 4px;
     background-color: scale-color-diff();
   }
 
   .badge-query-plan {
-    font-size: 12px;
+    font-size: 0.857em;
     line-height: 13px;
     padding: 4px;
     background-color: scale-color-diff();
@@ -483,7 +483,7 @@ section.details {
     .style-name {
       width: 54.0540%;
       height: 25px;
-      font-size: 20px;
+      font-size: 1.429em;
     }
     .ace-wrapper {
       position: relative;
@@ -590,7 +590,7 @@ section.details {
      padding-bottom: 20px;
   }
   td p {
-    font-size: 13px;
+    font-size: 0.929em;
     margin: 0 0 5px 0;
   }
   .flagged-posts { background: $danger; }
@@ -619,7 +619,7 @@ section.details {
   margin-top: 10px;
 
   .version-number {
-    font-size: 18px;
+    font-size: 1.286em;
     font-weight: bold;
     text-align: center;
   }
@@ -640,7 +640,7 @@ section.details {
   }
 
   .fa {
-    font-size: 26px;
+    font-size: 1.857em;
   }
 
   .up-to-date {
@@ -656,7 +656,7 @@ section.details {
 
 .update-nag {
   i.fa {
-    font-size: 20px;
+    font-size: 1.429em;
   }
 }
 
@@ -674,7 +674,7 @@ table.api-keys {
   }
 
   td.key {
-    font-size: 12px;
+    font-size: 0.857em;
   }
 }
 
@@ -748,7 +748,8 @@ table.api-keys {
       margin: 20px 10px 0 10px;
 
       .fa {
-        font-size: 32px;
+        font-size: 2.286em
+;
         vertical-align: middle;
         color: $primary
       }
@@ -837,7 +838,7 @@ table.api-keys {
     cursor: pointer;
 
     h1 {
-      font-size: 18px;
+      font-size: 1.286em;
       margin: 5px 0 0 8px;
       display: inline-block;
       line-height: 1.0em;
@@ -873,13 +874,13 @@ table.api-keys {
 
       .commit-message {
         color: $primary;
-        font-size: 12px;
+        font-size: 0.857em;
         font-weight: bold;
       }
 
       .commit-meta {
         color: $primary;
-        font-size: 12px;
+        font-size: 0.857em;
       }
 
       .committer-name {
@@ -909,7 +910,7 @@ table.api-keys {
 
   h3 {
     color: dark-light-diff($primary, $secondary, 50%, -60%);
-    font-size: 15px;
+    font-size: 1.071em;
     padding-left: 5px;
     margin-bottom: 10px;
   }
@@ -1259,7 +1260,7 @@ and (max-width : 500px) {
         width: 100%;
         }
       label {
-        font-size: 13px;
+        font-size: 0.929em;
         }
     }
   }
@@ -1305,7 +1306,7 @@ and (max-width : 500px) {
     border-bottom: 1px solid #dfdfdf;
   }
   .actions {
-    font-size: 17px;
+    font-size: 1.214em;
     float: right;
     a {
       margin-left: 5px;
diff --git a/app/assets/stylesheets/common/base/_topic-list.scss b/app/assets/stylesheets/common/base/_topic-list.scss
index 0248c7b793d..6a477b28890 100644
--- a/app/assets/stylesheets/common/base/_topic-list.scss
+++ b/app/assets/stylesheets/common/base/_topic-list.scss
@@ -8,7 +8,7 @@
   #navigation-bar {
     .has-icon span:before {
       margin-right: 4px;
-      font: 15px/0.9 "FontAwesome";
+      font: 1.071em/0.9 "FontAwesome";
     }
     .has-icon .starred:before {
       content: "\f005";
@@ -44,24 +44,24 @@
   th {
     color: scale-color($primary, $lightness: 50%);
     font-weight: normal;
-    font-size: 14px;
+    font-size: 1em;
     button i.fa {color: scale-color($primary, $lightness: 50%);}
 
   }
   td {
     color: scale-color($primary, $lightness: 50%);
-    font-size: 14px;
+    font-size: 1em;
   }
 
   .main-link {
-    font-size: 16px;
+    font-size: 1.143em;
     a.title {
       padding: 15px 0;
     }
   }
 
   .topic-excerpt {
-    font-size: 13px;
+    font-size: 0.929em;
     margin-top: 8px;
     color: scale-color($primary, $lightness: 50%);
     word-wrap: break-word;
@@ -74,7 +74,7 @@
   .topic-status {
     margin-right: 4px;
     padding: 0;
-    font-size: 15px;
+    font-size: 1.071em;
     &:last-of-type {
       margin-right: 0;
     }
@@ -141,7 +141,7 @@
         padding: 2px;
         vertical-align: bottom;
         line-height: 24px;
-        &.value { text-align: right; font-size: 20px; }
+        &.value { text-align: right; font-size: 1.429em; }
         &.unit  { text-align: left; }
       }
     }
@@ -169,7 +169,7 @@
   }
   .category-dropdown-button {
     border-left: 1px solid rgba(0,0,0,0.15);
-    font-size: 16px;
+    font-size: 1.143em;
     width: 10px;
     text-align: center;
 
@@ -190,7 +190,7 @@ clear: both;
     padding: 0;
     border: 0;
     color: scale-color($danger, $lightness: 20%);
-    font-size: 13px;
+    font-size: 0.929em;
     cursor: default;
   }
 }
@@ -198,7 +198,7 @@ clear: both;
 .topic-list {
   .alert {
     margin-bottom: 0;
-    font-size: 14px;
+    font-size: 1em;
   }
   .spinner {
     margin-top: 40px;
@@ -227,7 +227,7 @@ ol.category-breadcrumb {
   z-index: 100;
 
   a.badge-category {
-    font-size: 13px;
+    font-size: 0.929em;
     font-weight: bold;
     float: none;
     line-height: 19px;
@@ -263,7 +263,7 @@ ol.category-breadcrumb {
     outline: 0;
     background: transparent;
     border: 0;
-    font-size: 20px;
+    font-size: 1.429em;
     padding: 5px 10px 0 10px;
   }
 
diff --git a/app/assets/stylesheets/common/base/alert.scss b/app/assets/stylesheets/common/base/alert.scss
index 7c642fd2afc..c662ec7dba5 100644
--- a/app/assets/stylesheets/common/base/alert.scss
+++ b/app/assets/stylesheets/common/base/alert.scss
@@ -9,7 +9,7 @@
     right: -21px;
     line-height: 18px;
     float: right;
-    font-size: 20px;
+    font-size: 1.429em;
     font-weight: bold;
     line-height: 18px;
     color: $primary;
diff --git a/app/assets/stylesheets/common/base/colorpicker.scss b/app/assets/stylesheets/common/base/colorpicker.scss
index 4232d6ed751..e99830d88d0 100644
--- a/app/assets/stylesheets/common/base/colorpicker.scss
+++ b/app/assets/stylesheets/common/base/colorpicker.scss
@@ -22,7 +22,8 @@
       margin-right: 2px;
       width: 16px;
       height: 16px;
-      font-size: 4px;
+      font-size: 0.286em
+;
       &.used-color {
         background: image-url("chosen-sprite.png") -19px 13px;
       }
diff --git a/app/assets/stylesheets/common/base/combobox.scss b/app/assets/stylesheets/common/base/combobox.scss
index d6a478be7e3..4f0b6d1dc23 100644
--- a/app/assets/stylesheets/common/base/combobox.scss
+++ b/app/assets/stylesheets/common/base/combobox.scss
@@ -14,7 +14,7 @@
     /* leave this color as non-variable -- it is displayed on a white background in a dropdown */
     color: #333;
     margin: 6px 0 0 3px;
-    font-size: 12px;
+    font-size: 0.857em;
     line-height: 16px;
   }
 }
diff --git a/app/assets/stylesheets/common/base/compose.scss b/app/assets/stylesheets/common/base/compose.scss
index cfcfd296daa..16fa8f525ec 100644
--- a/app/assets/stylesheets/common/base/compose.scss
+++ b/app/assets/stylesheets/common/base/compose.scss
@@ -98,7 +98,7 @@ div.ac-wrap {
     margin-top: 10px;
   }
   label {
-    font-size: 14px;
+    font-size: 1em;
   }
   input {
     text-align: center;
@@ -118,7 +118,7 @@ div.ac-wrap {
   }
   .auto-close-fields {
     i.fa-clock-o {
-      font-size: 16px;
+      font-size: 1.143em;
       line-height: 8px;
     }
     input {
diff --git a/app/assets/stylesheets/common/base/discourse.scss b/app/assets/stylesheets/common/base/discourse.scss
index 7c8a30eb3a7..1617e3a3542 100644
--- a/app/assets/stylesheets/common/base/discourse.scss
+++ b/app/assets/stylesheets/common/base/discourse.scss
@@ -12,11 +12,11 @@
 }
 
 big {
-  font-size: 28px;
+  font-size: 2em;
 }
 
 small {
-  font-size: 10px;
+  font-size: 0.714em;
 }
 
 blockquote {
@@ -76,7 +76,7 @@ body {
 
   #loading-message {
     position: absolute;
-    font-size: 30px;
+    font-size: 2.143em;
     text-align: center;
     top: 120px;
     left: 500px;
@@ -96,7 +96,7 @@ body {
       margin-bottom: 20px;
     }
     p {
-      font-size: 20px;
+      font-size: 1.429em;
     }
   }
     #footer {
diff --git a/app/assets/stylesheets/common/base/exception.scss b/app/assets/stylesheets/common/base/exception.scss
index a1d4119813a..3b3282104d4 100644
--- a/app/assets/stylesheets/common/base/exception.scss
+++ b/app/assets/stylesheets/common/base/exception.scss
@@ -7,7 +7,7 @@
     height: 60px;
   }
   .reason {
-    font-size: 24px;
+    font-size: 1.714em;
     height: 24px;
   }
   .url {
diff --git a/app/assets/stylesheets/common/base/faqs.scss b/app/assets/stylesheets/common/base/faqs.scss
index 3d0581419c1..ec2faa72c49 100644
--- a/app/assets/stylesheets/common/base/faqs.scss
+++ b/app/assets/stylesheets/common/base/faqs.scss
@@ -13,7 +13,7 @@
   li,
   table {
     margin: 0 0 20px;
-    font-size: 16px;
+    font-size: 1.143em;
     line-height: 22px;
   }
 
diff --git a/app/assets/stylesheets/common/base/header.scss b/app/assets/stylesheets/common/base/header.scss
index 38b5ada1d44..f0ca7111ebe 100644
--- a/app/assets/stylesheets/common/base/header.scss
+++ b/app/assets/stylesheets/common/base/header.scss
@@ -29,7 +29,7 @@
     }
 
     .fa-home {
-      font-size: 23px;
+      font-size: 1.643em;
     }
 
     .panel {
@@ -107,7 +107,7 @@
       [class^="fa fa-"] {
         width: 32px;
         height: 32px;
-        font-size: 24px;
+        font-size: 1.714em;
         line-height: 32px;
         display: inline-block;
       }
@@ -160,7 +160,7 @@
   }
 
   li:not(.category):not(.heading) {
-    font-size: 13px;
+    font-size: 0.929em;
     line-height: 16px;
 
       .fa {
diff --git a/app/assets/stylesheets/common/base/lightbox.scss b/app/assets/stylesheets/common/base/lightbox.scss
index 7b6f850858a..142d4b1b628 100644
--- a/app/assets/stylesheets/common/base/lightbox.scss
+++ b/app/assets/stylesheets/common/base/lightbox.scss
@@ -39,7 +39,7 @@
     margin: 6px;
     padding-right: 20px;
     color: scale-color($primary, $lightness: 50%);
-    font-size: 14px;
+    font-size: 1em;
   }
 
   .expand {
diff --git a/app/assets/stylesheets/common/base/login.scss b/app/assets/stylesheets/common/base/login.scss
index 5f5dc26d012..6d202a716b0 100644
--- a/app/assets/stylesheets/common/base/login.scss
+++ b/app/assets/stylesheets/common/base/login.scss
@@ -1,6 +1,6 @@
 .caps-lock-warning {
   color: $danger;
-  font-size: 12px;
+  font-size: 0.857em;
   font-weight: bold;
 }
 
diff --git a/app/assets/stylesheets/common/base/magnific-popup.scss b/app/assets/stylesheets/common/base/magnific-popup.scss
index 57b1ee9c1a5..a0c98d3051c 100644
--- a/app/assets/stylesheets/common/base/magnific-popup.scss
+++ b/app/assets/stylesheets/common/base/magnific-popup.scss
@@ -287,7 +287,7 @@ button {
   color: $controls-color;
 
   font-style: normal;
-  font-size: 28px;
+  font-size: 2em;
   font-family: Arial, Baskerville, monospace;
 
   &:hover,
@@ -324,7 +324,7 @@ button {
   top: 0;
   right: 0;
   color: $controls-text-color;
-  font-size: 12px;
+  font-size: 0.857em;
   line-height: 18px;
 }
 
@@ -489,7 +489,7 @@ button {
     small {
       color: $caption-subtitle-color;
       display: block;
-      font-size: 12px;
+      font-size: 0.857em;
       line-height: 14px;
     }
     figure {
diff --git a/app/assets/stylesheets/common/base/modal.scss b/app/assets/stylesheets/common/base/modal.scss
index 0d823574167..f3c9178b8ee 100644
--- a/app/assets/stylesheets/common/base/modal.scss
+++ b/app/assets/stylesheets/common/base/modal.scss
@@ -88,7 +88,7 @@
     padding: 10px 30px 10px 15px;
     background-color: dark-light-diff($secondary, $primary, 10%, -15%);
     li > a {
-      font-size: 14px;
+      font-size: 1em;
     }
     border-bottom: 1px solid scale-color-diff();
 
@@ -108,7 +108,7 @@
     }
     p {
       color: darken($primary, 40%);;
-      font-size: 13px;
+      font-size: 0.929em;
     }
     .archetype-option {
       margin-bottom: 20px;
@@ -133,14 +133,14 @@
   .modal-footer {
     .btn {
       text-align: left;
-      font-size: 18px;
+      font-size: 1.286em;
       line-height: 20px;
       width: 310px;
       margin-bottom: 10px;
       display: block;
       margin-left: 0;
       .topic-title {
-        font-size: 13px;
+        font-size: 0.929em;
         font-weight: normal;
       }
       &.btn-reply-here {
@@ -163,7 +163,7 @@
     .btn {
       font-weight: normal;
       text-align: left;
-      font-size: 14px;
+      font-size: 1em;
       line-height: 20px;
       margin-bottom: 10px;
       display: inline-block;
diff --git a/app/assets/stylesheets/common/base/onebox.scss b/app/assets/stylesheets/common/base/onebox.scss
index d00abbc3549..120b7158e99 100644
--- a/app/assets/stylesheets/common/base/onebox.scss
+++ b/app/assets/stylesheets/common/base/onebox.scss
@@ -15,7 +15,7 @@ a.loading-onebox {
   padding: 12px 25px 12px 12px;
   border-left: 5px solid darken(scale-color-diff(), 10%);
   background: scale-color-diff();
-  font-size: 14px;
+  font-size: 1em;
   > .source {
     margin-bottom: 12px;
     margin-right: 10px;
@@ -30,7 +30,7 @@ a.loading-onebox {
         padding-right: 10px;
       }
       position: absolute;
-      font-size: 14px;
+      font-size: 1em;
       img.favicon {
         margin-right: 3px;
       }
@@ -92,7 +92,7 @@ aside.onebox {
   padding: 12px 25px 12px 12px;
   border-left: 5px solid darken(scale-color-diff(), 10%);
   background: scale-color-diff();
-  font-size: 14px;
+  font-size: 1em;
 
   header {
     a[href] {
diff --git a/app/assets/stylesheets/common/base/request_access.scss b/app/assets/stylesheets/common/base/request_access.scss
index b67de033444..63c95bc7e5c 100644
--- a/app/assets/stylesheets/common/base/request_access.scss
+++ b/app/assets/stylesheets/common/base/request_access.scss
@@ -4,10 +4,10 @@
   input[type=text] {
     width: 320px;
     height: 30px;
-    font-size: 22px;
+    font-size: 1.571em;
   }
   input[type=submit] {
-    font-size: 22px;
+    font-size: 1.571em;
     padding: 10px;
   }
 }
diff --git a/app/assets/stylesheets/common/base/rtl.scss b/app/assets/stylesheets/common/base/rtl.scss
index 2f12c9316b4..86c0dd653f2 100644
--- a/app/assets/stylesheets/common/base/rtl.scss
+++ b/app/assets/stylesheets/common/base/rtl.scss
@@ -29,7 +29,7 @@
   }
 
   #topic-title h1 a.edit-topic {
-    font-size: 15px;
+    font-size: .9em;
     position: absolute;
     margin-right: 8px;
     margin-left: 0;
@@ -52,7 +52,7 @@
   }
 
   #topic-title .star {
-    font-size: 20px;
+    font-size: 1.429em;
     margin-top: 6px;
     margin-left: 6px;
   }
@@ -65,7 +65,7 @@
   .topic-meta-data-inside {
     margin-top: -22px;
     float: left;
-    font-size: 12px;
+    font-size: 0.857em;
   }
   .post-info a {
     color: #B3B3B3;
@@ -98,7 +98,7 @@
   }
 
   .reply-new i {
-    font-size: 12px;
+    font-size: 0.857em;
     margin-left: 5px;
     background: none repeat scroll 0% 0% #FFF;
     border: 1px solid #E6E6E6;
@@ -123,7 +123,7 @@
   .dropdown-menu .icon {
     margin-top: 3px;
     float: right;
-    font-size: 18px;
+    font-size: 1.286em;
   }
 
   .topic-list th, .topic-list td {
@@ -151,14 +151,14 @@
   #share-link .link {
     margin-right: 2px;
     float: left;
-    font-size: 20px;
+    font-size: 1.429em;
   }
 
   #share-link .social-link {
     margin-right: 2px;
     margin-left: 8px;
     float: right;
-    font-size: 22px;
+    font-size: 1.571em;
   }
 
   body .radio input[type="radio"], body .checkbox input[type="checkbox"] {
@@ -173,7 +173,7 @@
 
   .modal-header .close {
     float: left;
-    font-size: 20px;
+    font-size: 1.429em;
     margin: 10px 10px 0px;
     text-decoration: none;
     color: #B3B3B3;
@@ -216,7 +216,7 @@
     height: 13px;
     left: 13px;
     position: absolute;
-    font-size: 15px;
+    font-size: 1.071em;
     color: #333;
     text-decoration: none;
     right: auto;
@@ -252,14 +252,14 @@
 
   #navigation-bar .has-icon span:before {
     margin-left: 4px;
-    font: 15px/0.9 "FontAwesome";
+    font: 1.071em/0.9 "FontAwesome";
   }
 
   .list-controls .btn {
     float: left;
     margin-right: 8px;
     margin-bottom: 10px;
-    font-size: 16px;
+    font-size: 1.143em;
     font-weight: normal;
   }
 
@@ -290,7 +290,7 @@
   }
 
   .category-dropdown-menu a.badge-category {
-    font-size: 13px;
+    font-size: 0.929em;
     font-weight: bold;
     padding: 4px 0px;
     float: none;
@@ -308,7 +308,7 @@
     float: left;
     color: #333;
     opacity: 0.5;
-    font-size: 15px;
+    font-size: 1.071em;
   }
 
   #topic-progress {
diff --git a/app/assets/stylesheets/common/base/share_link.scss b/app/assets/stylesheets/common/base/share_link.scss
index 9cf2a61b43b..0646670492f 100644
--- a/app/assets/stylesheets/common/base/share_link.scss
+++ b/app/assets/stylesheets/common/base/share_link.scss
@@ -19,18 +19,18 @@
     margin: 14px 0;
   }
   h3 {
-    font-size: 13px;
+    font-size: 0.929em;
   }
   .social-link {
     margin-left: 2px;
     margin-right: 8px;
     float: left;
-    font-size: 22px;
+    font-size: 1.571em;
   }
   .link {
     margin-right: 2px;
     float: right;
-    font-size: 20px;
+    font-size: 1.429em;
     a {
       color: $primary;
     }
@@ -48,7 +48,7 @@
   }
 
   input[type=text] {
-    font-size: 16px;
+    font-size: 1.143em;
     margin-bottom: 10px;
   }
 }
diff --git a/app/assets/stylesheets/common/base/topic-post.scss b/app/assets/stylesheets/common/base/topic-post.scss
index d524b5e0455..b03c049669f 100644
--- a/app/assets/stylesheets/common/base/topic-post.scss
+++ b/app/assets/stylesheets/common/base/topic-post.scss
@@ -4,7 +4,7 @@
    font-weight: bold;
  }
  span {
-   font-size: 13px;
+   font-size: 0.929em;
    padding-right: 8px;
    display: inline-block;
    max-width: 280px;
@@ -125,7 +125,7 @@ aside.quote {
   &.wiki, &.via-email {
     margin-right: 5px;
     i.fa {
-      font-size: 14px;
+      font-size: 1em;
     }
   }
   &.wiki {
@@ -159,7 +159,7 @@ kbd
   box-shadow: 0 1px 0 rgba(0,0,0, .8);
   color: $primary;
   display: inline-block;
-  font-size: 12px;
+  font-size: 0.857em;
   line-height: 1.4;
   margin: 0 .1em;
   padding: .1em .6em;
diff --git a/app/assets/stylesheets/common/base/topic.scss b/app/assets/stylesheets/common/base/topic.scss
index 5a07e3db7f6..90112f72d37 100644
--- a/app/assets/stylesheets/common/base/topic.scss
+++ b/app/assets/stylesheets/common/base/topic.scss
@@ -8,7 +8,7 @@
 
   h1 {
     a.edit-topic {
-      font-size: 17px;
+      font-size: 1.214em;
       display: inline-block;
       vertical-align: top;
       position: relative;
diff --git a/app/assets/stylesheets/common/base/upload.scss b/app/assets/stylesheets/common/base/upload.scss
index da091d287b6..60c1f55785f 100644
--- a/app/assets/stylesheets/common/base/upload.scss
+++ b/app/assets/stylesheets/common/base/upload.scss
@@ -1,5 +1,5 @@
 .add-upload .fa-plus {
-  font-size: 10px;
+  font-size: 0.714em;
   position: relative;
   left: -5px;
   bottom: -5px;
diff --git a/app/assets/stylesheets/common/base/user-badges.scss b/app/assets/stylesheets/common/base/user-badges.scss
index 17cce459731..657aba3d2bd 100644
--- a/app/assets/stylesheets/common/base/user-badges.scss
+++ b/app/assets/stylesheets/common/base/user-badges.scss
@@ -47,7 +47,7 @@
 
     .fa {
       display: block;
-      font-size: 50px;
+      font-size: 3.571em;
       margin-bottom: 5px;
     }
 
@@ -135,7 +135,7 @@ table.badges-listing {
     .date {
       display: block;
       color: lighten($primary, 40%);
-      font-size: 10px;
+      font-size: 0.714em;
     }
   }
 }
diff --git a/app/assets/stylesheets/common/base/user.scss b/app/assets/stylesheets/common/base/user.scss
index 1e77ac0b824..004c09f5dbf 100644
--- a/app/assets/stylesheets/common/base/user.scss
+++ b/app/assets/stylesheets/common/base/user.scss
@@ -49,7 +49,7 @@
   }
   h2 {
     a {
-      font-size: 14px;
+      font-size: 1em;
       color: scale-color($tertiary, $lightness: -10%);;
       cursor: pointer;
     }
diff --git a/app/assets/stylesheets/common/base/username_tagsinput.scss b/app/assets/stylesheets/common/base/username_tagsinput.scss
index 6b91110174f..8e0f60dca90 100644
--- a/app/assets/stylesheets/common/base/username_tagsinput.scss
+++ b/app/assets/stylesheets/common/base/username_tagsinput.scss
@@ -24,7 +24,7 @@ div.tagsinput span.tag {
 }
 
 div.tagsinput span.tag a { font-weight: bold; color: #82ad2b; text-decoration:none; font-size: 11px;  }
-div.tagsinput input { width:80px; margin:0px; font-family: helvetica; font-size: 13px; border:1px solid transparent;
+div.tagsinput input { width:80px; margin:0px; font-family: helvetica; font-size: 0.929em; border:1px solid transparent;
 padding:2px 5px; background: transparent; color: #000; outline:0px;  margin-right:5px; margin-bottom:5px; }
 div.tagsinput div { display:block; float: left; }
 .tags_clear { clear: both; width: 100%; height: 0; }
diff --git a/app/assets/stylesheets/common/components/badges.css.scss b/app/assets/stylesheets/common/components/badges.css.scss
index 3525a141199..7549e5f5634 100644
--- a/app/assets/stylesheets/common/components/badges.css.scss
+++ b/app/assets/stylesheets/common/components/badges.css.scss
@@ -16,7 +16,7 @@
 // --------------------------------------------------
 
 .badge-category, .badge-category-parent {
-  font-size: 12px;
+  font-size: 0.857em;
   font-weight: bold;
   white-space: nowrap;
   display: inline-block;
@@ -84,7 +84,7 @@ h1 a.badge-category div {vertical-align: top;}
     background-color: transparent;
     color: scale-color($tertiary, $lightness: 20%);
     font-weight: normal;
-    font-size: 13px;
+    font-size: 0.929em;
   }
 
   &.new-topic::before {
@@ -110,7 +110,7 @@ h1 a.badge-category div {vertical-align: top;}
 
 .badge-posts {
   font-weight: normal;
-  font-size: 14px;
+  font-size: 1em;
   line-height: 1;
   &[href] {
     color: scale-color($primary, $lightness: 40%);
@@ -127,6 +127,6 @@ h1 a.badge-category div {vertical-align: top;}
   text-shadow: 0 1px 0 rgba($primary, 0.1);
   background-color: dark-light-diff($primary, $secondary, 90%, -65%);
   border-color: dark-light-diff($primary, $secondary, 90%, -65%);
-  font-size: 12px;
+  font-size: 0.857em;
   box-shadow: inset 0 1px 0 rgba(0,0,0, 0.22);
 }
diff --git a/app/assets/stylesheets/common/components/banner.css.scss b/app/assets/stylesheets/common/components/banner.css.scss
index da79d049a52..7047147b8ea 100644
--- a/app/assets/stylesheets/common/components/banner.css.scss
+++ b/app/assets/stylesheets/common/components/banner.css.scss
@@ -16,7 +16,7 @@
   }
 
   .close {
-    font-size: 25px !important;
+    font-size: 1.786em !important;
     margin-top: -10px !important;
     color: darken($tertiary, 45%);
   }
diff --git a/app/assets/stylesheets/common/components/buttons.css.scss b/app/assets/stylesheets/common/components/buttons.css.scss
index e21b1a663de..87ae96a6cb6 100644
--- a/app/assets/stylesheets/common/components/buttons.css.scss
+++ b/app/assets/stylesheets/common/components/buttons.css.scss
@@ -10,7 +10,7 @@
   margin: 0;
   padding: 6px 12px;
   font-weight: 500;
-  font-size: 14px;
+  font-size: 1em;
   line-height: 18px;
   text-align: center;
   cursor: pointer;
@@ -173,7 +173,7 @@
 
 .btn-small {
   padding: 3px 6px;
-  font-size: 12px;
+  font-size: 0.857em;
   line-height: 16px;
 }
 
@@ -181,6 +181,6 @@
 
 .btn-large {
   padding: 9px 18px;
-  font-size: 16px;
+  font-size: 1.143em;
   line-height: 20px;
 }
diff --git a/app/assets/stylesheets/common/components/navs.css.scss b/app/assets/stylesheets/common/components/navs.css.scss
index 92d8c350b92..5934c2fb740 100644
--- a/app/assets/stylesheets/common/components/navs.css.scss
+++ b/app/assets/stylesheets/common/components/navs.css.scss
@@ -27,7 +27,7 @@
       border: none;
       padding: 5px 12px;
       color: $primary;
-      font-size: 16px;
+      font-size: 1.143em;
       line-height: 20px;
       transition: background .15s;
       &:hover {
@@ -59,7 +59,7 @@
     > a {
       margin: 0;
       padding: 13px 13px 13px 30px;
-      font-size: 16px;
+      font-size: 1.143em;
       line-height: 20px;
       cursor: pointer;
       color: $primary;
@@ -83,12 +83,12 @@
   }
 
   .count {
-    font-size: 12px;
+    font-size: 0.857em;
     line-height: 16px;
   }
 
   .glyph {
-    font-size: 12px;
+    font-size: 0.857em;
     width: 30px;
     text-align: center;
     position: absolute;
diff --git a/app/assets/stylesheets/common/foundation/variables.scss b/app/assets/stylesheets/common/foundation/variables.scss
index cae47ff5e1c..bd4a0e90f0d 100644
--- a/app/assets/stylesheets/common/foundation/variables.scss
+++ b/app/assets/stylesheets/common/foundation/variables.scss
@@ -22,8 +22,8 @@ $github: #6d6d6d !default;
 // Fonts
 // --------------------------------------------------
 
-$base-font-size: 14px !default;
-$base-line-height: 19px !default;
+$base-font-size: 0.875em !default; //14px base
+$base-line-height: 1.357em !default; 
 $base-font-family: Helvetica, Arial, sans-serif !default;
 
 /* These files don't actually exist. They're injected by DiscourseSassImporter. */
diff --git a/app/assets/stylesheets/common/input_tip.scss b/app/assets/stylesheets/common/input_tip.scss
index efd4fdbfa02..fae0176e2a7 100644
--- a/app/assets/stylesheets/common/input_tip.scss
+++ b/app/assets/stylesheets/common/input_tip.scss
@@ -18,7 +18,7 @@
     float: right;
     color: $primary;
     opacity: 0.5;
-    font-size: 15px;
+    font-size: 1.071em;
     margin: 0 0 0 4px;
     cursor: pointer;
   }
diff --git a/app/assets/stylesheets/common/topic-entrance.scss b/app/assets/stylesheets/common/topic-entrance.scss
index 24e2d60d05c..b00d025168f 100644
--- a/app/assets/stylesheets/common/topic-entrance.scss
+++ b/app/assets/stylesheets/common/topic-entrance.scss
@@ -20,7 +20,7 @@
       display: block;
       margin-top: 2px;
       margin-bottom: 2px;
-      font-size: 18px;
+      font-size: 1.286em;
     }
   }
   button.btn.jump-bottom {
diff --git a/app/assets/stylesheets/desktop/compose.scss b/app/assets/stylesheets/desktop/compose.scss
index 90f320ca7dd..033287e4035 100644
--- a/app/assets/stylesheets/desktop/compose.scss
+++ b/app/assets/stylesheets/desktop/compose.scss
@@ -41,7 +41,7 @@
     float: right;
     color: $primary;
     opacity: 0.5;
-    font-size: 15px;
+    font-size: 1.071em;
   }
 
   a.close:hover {
@@ -73,7 +73,7 @@
 
   .posts-count {
     color: scale-color($tertiary, $lightness: -40%);
-    font-size: 12px;
+    font-size: 0.857em;
   }
 }
 
@@ -93,7 +93,7 @@
   }
   #file-uploading {
     left: 51%;
-    font-size: 12px;
+    font-size: 0.857em;
     color: $primary;
   }
   #draft-status {
@@ -109,13 +109,13 @@
   height: 0;
   background-color: scale-color-diff();
   bottom: 0;
-  font-size: 14px;
+  font-size: 1em;
   position: fixed;
   .toggler {
     width: 15px;
     right: 1px;
     position: absolute;
-    font-size: 15px;
+    font-size: 1.071em;
     color: $primary;
     padding: 0 10px 5px 10px;
     &:before {
@@ -383,7 +383,7 @@
       @include border-radius-all(0);
     }
     #wmd-preview-scroller {
-      font-size: 13px;
+      font-size: 0.929em;
       line-height: 18px;
       font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
       overflow: scroll;
diff --git a/app/assets/stylesheets/desktop/discourse.scss b/app/assets/stylesheets/desktop/discourse.scss
index d346a4fec14..4315f3cee35 100644
--- a/app/assets/stylesheets/desktop/discourse.scss
+++ b/app/assets/stylesheets/desktop/discourse.scss
@@ -2,7 +2,7 @@
 // BEWARE: changing these styles implies they take effect anywhere they are seen
 // throughout the Discourse application
 
-html {font-size: 14px/19px;}
+html {font-size: $base-font-size/$base-line-height;}
 
 @include medium-width {
   body {
@@ -110,7 +110,7 @@ body {
     padding: 0 2px 0 0;
     margin: 0;
     i {
-        font-size: 15px;
+        font-size: 1.071em;
           }
   }
 
@@ -165,7 +165,7 @@ body {
     margin: 0 0 18px;
   }
   label, input, button, select, textarea {
-    font-size: 13px;
+    font-size: 0.929em;
     font-weight: normal;
     line-height: 18px;
   }
@@ -180,7 +180,7 @@ body {
     display: inline-block;
     padding: 4px;
     margin-bottom: 9px;
-    font-size: 13px;
+    font-size: 0.929em;
     line-height: 18px;
     color: $primary;
   }
@@ -190,7 +190,7 @@ body {
       height: 18px;
       padding: 4px;
       margin-bottom: 9px;
-      font-size: 13px;
+      font-size: 0.929em;
       line-height: 18px;
       color: $primary;
     }
diff --git a/app/assets/stylesheets/desktop/history.scss b/app/assets/stylesheets/desktop/history.scss
index 83c021445fc..efb72c4cd9b 100644
--- a/app/assets/stylesheets/desktop/history.scss
+++ b/app/assets/stylesheets/desktop/history.scss
@@ -40,7 +40,7 @@
   }
   .markdown {
     font-family: monospace;
-    font-size: 12px;
+    font-size: 0.857em;
     width: 100%;
     border-collapse: collapse;
     border-spacing: 0;
diff --git a/app/assets/stylesheets/desktop/modal.scss b/app/assets/stylesheets/desktop/modal.scss
index 114d209fec8..59cdbd74f48 100644
--- a/app/assets/stylesheets/desktop/modal.scss
+++ b/app/assets/stylesheets/desktop/modal.scss
@@ -66,14 +66,14 @@ animation: modal .25s;
 .modal-header {
   border-bottom: 1px solid scale-color-diff();
   h3 {
-    font-size: 20px;
+    font-size: 1.429em;
     padding: 10px 15px 7px;
   }
   .close {margin: 10px;}
 }
 .close {
   float: right;
-  font-size: 20px;
+  font-size: 1.429em;
   text-decoration: none;
   color: scale-color($primary, $lightness: 35%);
   cursor: pointer;
diff --git a/app/assets/stylesheets/desktop/topic-list.scss b/app/assets/stylesheets/desktop/topic-list.scss
index b1c54815fac..d2a6279e4a7 100644
--- a/app/assets/stylesheets/desktop/topic-list.scss
+++ b/app/assets/stylesheets/desktop/topic-list.scss
@@ -15,13 +15,13 @@
     float: right;
     margin-left: 8px;
     margin-bottom: 10px;
-    font-size: 16px;
+    font-size: 1.143em;
     font-weight: normal;
   }
 
   a.badge-category {
     padding: 3px 12px;
-    font-size: 16px;
+    font-size: 1.143em;
 
     &.category-dropdown-button {
       height: 24px;
@@ -168,7 +168,7 @@
 .topic-list.categories {
   a.title {
     color: $tertiary;
-    font-size: 13px;
+    font-size: 0.929em;
   }
   a.title:visited:not(.badge-notification) {color: scale-color($tertiary, $lightness: 35%);}
 
@@ -186,7 +186,7 @@
   th .toggle-admin {
     position: absolute;
     padding: 3px 8px;
-    font-size: 12px;
+    font-size: 0.857em;
     right: -35px;
     top: 4px;
   }
@@ -204,7 +204,7 @@
     padding: 8px;
   }
   .last-user-info {
-    font-size: 12px;
+    font-size: 0.857em;
   }
   .has-description {
     td.category {
@@ -217,7 +217,7 @@
 
     h3 {
       display: inline-block;
-      font-size: 18px;
+      font-size: 1.286em;
       a[href] {
         color: $primary;
       }
@@ -237,23 +237,23 @@
     }
     .badge-category.bigger {
       padding: 6px 10px;
-      font-size: 14px;
+      font-size: 1em;
     }
   }
 
   .featured-topic {
     margin: 10px 0 0;
-    font-size: 13px;
+    font-size: 0.929em;
     /* topic status glyphs */
     i {
       color: scale-color($primary, $lightness: 50%) !important;
-      font-size: 13px;
+      font-size: 0.929em;
     }
     a.last-posted-at, a.last-posted-at:visited {
       color: scale-color($primary, $lightness: 50%);
     }
     .badge {
-      font-size: 10px;
+      font-size: 0.714em;
       top: -1px;
     }
   }
@@ -331,7 +331,7 @@ and (max-width : 850px) {
 
   .nav-pills {
     > li > a {
-      font-size: 14px;
+      font-size: 1em;
       padding: 5px 10px ;
       }
   }
@@ -340,7 +340,7 @@ and (max-width : 850px) {
     padding: 0 5px;
 
     .btn {
-        font-size: 14px
+        font-size: 1em
       }
 
     .category-dropdown-menu {
@@ -348,7 +348,7 @@ and (max-width : 850px) {
       }
 
     a.badge-category {
-        font-size: 14px;
+        font-size: 1em;
       }
 
   }
@@ -370,14 +370,14 @@ and (max-width : 850px) {
      }
    th, td {
       padding: 12px 2px;
-      font-size: 13px;
+      font-size: 0.929em;
      }
     .star {
       padding: 12px 5px;
       width: auto;
       }
     .main-link {
-      font-size: 15px;
+      font-size: 1.071em;
       padding: 12px 8px 12px 0px;
       }
 
diff --git a/app/assets/stylesheets/desktop/topic-post.scss b/app/assets/stylesheets/desktop/topic-post.scss
index 6b5345d99de..eca6ac75b49 100644
--- a/app/assets/stylesheets/desktop/topic-post.scss
+++ b/app/assets/stylesheets/desktop/topic-post.scss
@@ -10,7 +10,7 @@
 }
 
 h1 .topic-statuses .topic-status i {
-  font-size: 20px;
+  font-size: 1.429em;
   vertical-align: middle;
 }
 
@@ -31,7 +31,7 @@ h1 .topic-statuses .topic-status i {
 
 .reply-to-tab {
   z-index: 400;
-  font-size: 13px;
+  font-size: 0.929em;
   float: right;
   margin: 1px 25px 0 0;
   color: scale-color($primary, $lightness: 50%);
@@ -135,7 +135,7 @@ nav.post-controls {
   }
 
   button {
-    font-size: 16px;
+    font-size: 1.143em;
     padding: 8px 10px;
     vertical-align: top;
     background: transparent;
@@ -291,7 +291,7 @@ nav.post-controls {
   .topic-meta-data h5 {
     position: absolute;
     z-index: 1;
-    font-size: 13px;
+    font-size: 0.929em;
     a {
       font-weight: bold;
       color: scale-color($primary, $lightness: 30%);
@@ -338,7 +338,7 @@ a.star {
     margin: 1px 0 2px 0;
     color: scale-color($primary, $lightness: 50%);
     font-weight: normal;
-    font-size: 12px;
+    font-size: 0.857em;
     line-height: 15px;
   }
 
@@ -348,7 +348,7 @@ a.star {
   }
 
   span.domain {
-    font-size: 10px;
+    font-size: 0.714em;
     color: scale-color($primary, $lightness: 50%);
   }
 
@@ -447,7 +447,7 @@ a.star {
       }
       .fa {
         margin: 0;
-        font-size: 18px;
+        font-size: 1.286em;
         line-height: 52px;
       }
     }
@@ -488,7 +488,7 @@ a.star {
   }
 
    .title {
-    font-size: 14px; line-height: 8px;
+    font-size: 1em; line-height: 8px;
    }
 }
 
@@ -557,7 +557,7 @@ video {
 
   a.star {
     margin: 0 7px 20px 2px;
-    font-size: 17px;
+    font-size: 1.214em;
     color: dark-light-diff($secondary, $primary, 80%, -20%) !important;
   }
   a.star.starred {color: $danger !important;}
@@ -648,7 +648,7 @@ a.mention {
 }
 
 .deleted-user-avatar {
-  font-size: 36px;
+  font-size: 2.571em;
 }
 
 .info-line {
@@ -708,7 +708,7 @@ blockquote > *:last-child {
 
   ul {margin: 0;}
   li {margin-bottom: 10px;}
-  i {font-size: 12px;}
+  i {font-size: 0.857em;}
 
   .reply-new {
     padding-left: 27px;
@@ -808,8 +808,8 @@ $topic-avatar-width: 45px;
   border: 1px solid scale-color-diff();
   box-shadow: 0 1px 5px rgba(0,0,0, .4);
   background-clip: padding-box;
-  span {font-size: 12px;}
-  .title {font-weight: bold; display: block; font-size: 14px;}
+  span {font-size: 0.857em;}
+  .title {font-weight: bold; display: block; font-size: 1em;}
 }
 .dropdown-menu a {
   display: block;
@@ -844,7 +844,7 @@ $topic-avatar-width: 45px;
 .dropdown-menu .icon {
   margin-top: 3px;
   float: left;
-  font-size: 18px;
+  font-size: 1.286em;
 }
 
 .open > .dropdown-menu {
@@ -879,14 +879,14 @@ $topic-avatar-width: 45px;
     margin-top: 10px;
   }
   p {
-    font-size: 13px;
+    font-size: 0.929em;
     margin: 0 0 10px 0;
   }
   p.cancel {
     margin: 10px 0 0 0;
   }
   h3 {
-    font-size: 25px;
+    font-size: 1.786em;
     color: $primary;
     margin-bottom: 5px;
     i {
@@ -974,7 +974,7 @@ a.attachment:before {
     position: absolute;
     left: 767px;
     color: rgba(dark-light-diff($primary, $secondary, 90%, -65%) , .8);
-    font: 90px/1 FontAwesome;
+    font: 6.429em/1 FontAwesome;
     content: "\f014";
     z-index: -5;
 }
@@ -993,7 +993,7 @@ a.attachment:before {
  .post-info  {
    display: inline-block;
    float: right;
-   font-size: 13px;
+   font-size: 0.929em;
    margin-top: 1px;
    a {color: scale-color($primary, $lightness: 50%);}
  }
@@ -1013,7 +1013,7 @@ span.highlighted {
   position: absolute;
   right: -2px;
   top: 13px;
-  font-size: 8px;
+  font-size: 0.571em;
 }
 
 .read-state.read {
diff --git a/app/assets/stylesheets/desktop/topic.scss b/app/assets/stylesheets/desktop/topic.scss
index dd86e876053..feabe7f35bf 100644
--- a/app/assets/stylesheets/desktop/topic.scss
+++ b/app/assets/stylesheets/desktop/topic.scss
@@ -20,7 +20,7 @@
   padding-top: 14px;
   margin-bottom: 10px;
   .star {
-    font-size: 20px;
+    font-size: 1.429em;
     margin-top: 6px;
     margin-right: 6px;
   }
@@ -91,7 +91,7 @@ a:hover.reply-new {
   width: 60%;
   margin-left: auto;
   margin-right: auto;
-  font-size: 24px;
+  font-size: 1.714em;
   text-align: center;
   line-height: 1.1em;
 
@@ -140,7 +140,7 @@ a:hover.reply-new {
       display: block;
       margin-top: 2px;
       margin-bottom: 2px;
-      font-size: 18px;
+      font-size: 1.286em;
     }
   }
   .jump-form {
@@ -150,7 +150,7 @@ a:hover.reply-new {
       height: 20px;
       text-align: center;
       margin-bottom: 0;
-      font-size: 16px;
+      font-size: 1.143em;
     }
     button.btn {
       float: right;
@@ -195,7 +195,7 @@ a:hover.reply-new {
   }
   h4 {
     display: inline;
-    font-size: 18px;
+    font-size: 1.286em;
     line-height: 15px;
   }
   .bg {
@@ -236,7 +236,7 @@ a:hover.reply-new {
   bottom: 0;
   position: fixed;
   width: 100%;
-  font-size: 15px;
+  font-size: 1.071em;
   z-index: 495
 }
 
diff --git a/app/assets/stylesheets/desktop/upload.scss b/app/assets/stylesheets/desktop/upload.scss
index 7470b4a2ef1..80d0667cacf 100644
--- a/app/assets/stylesheets/desktop/upload.scss
+++ b/app/assets/stylesheets/desktop/upload.scss
@@ -13,7 +13,7 @@
         margin: 0 0 5px 0;
       }
       input[type="file"] {
-        font-size: 14px;
+        font-size: 1em;
         line-height: 18px;
       }
       .description, .hint {
diff --git a/app/assets/stylesheets/desktop/user-card.scss b/app/assets/stylesheets/desktop/user-card.scss
index 2a4f7ff6817..5a5703b7439 100644
--- a/app/assets/stylesheets/desktop/user-card.scss
+++ b/app/assets/stylesheets/desktop/user-card.scss
@@ -43,7 +43,7 @@
   h1 {
     display: inline-block;
     min-width: 120px;
-    font-size: 25px;
+    font-size: 1.786em;
     line-height: 1.25;
     display: block;
     max-width: 250px;
@@ -54,13 +54,13 @@
       color: $secondary;
     }
     i {
-      font-size: 18px;
+      font-size: .8em;
       color: $secondary;
     }
   }
 
   h2 {
-    font-size: 15px;
+    font-size: 1.071em;
     line-height: 1.25;
     font-weight: normal;
     display: block;
@@ -74,7 +74,7 @@
   }
 
   h3 {
-    font-size: 13px;
+    font-size: 0.929em;
     font-weight: normal;
     margin-top: 0;
     color: dark-light-diff($secondary, $primary, 25%, -25%);
@@ -85,7 +85,7 @@
     }
   }
   .groups {
-    font-size: 13px;
+    font-size: 0.929em;
     font-weight: normal;
     margin-top: 0;
     color: $primary;
@@ -201,7 +201,7 @@
 
       h3 {
         color: $primary;
-        font-size: 14px;
+        font-size: 1em;
         margin-bottom: -8px;
       }
     }
@@ -226,7 +226,7 @@
     position: absolute;
     right: 12px;
     bottom: 12px;
-    font-size: 30px;
+    font-size: 2.143em;
     i {color: $secondary;}
   }
 }
diff --git a/app/assets/stylesheets/desktop/user.scss b/app/assets/stylesheets/desktop/user.scss
index e3ac208f716..41e6923ab24 100644
--- a/app/assets/stylesheets/desktop/user.scss
+++ b/app/assets/stylesheets/desktop/user.scss
@@ -198,7 +198,7 @@
 
   .secondary {
     background: dark-light-diff($primary, $secondary, 90%, -65%);
-    font-size: 13px;
+    font-size: 0.929em;
       .btn { padding: 3px 12px; }
 
       dl dd {
@@ -246,12 +246,13 @@
       transition: margin .15s linear;
 
       h1 {
-        font-size: 30px;
+        font-size: 2.143em;
         font-weight: normal;
+        i {font-size: .8em;}
       }
 
       h2 {
-        font-size: 17px;
+        font-size: 1.214em;
         font-weight: normal;
         margin-top: 10px;
         max-width: 100%;
@@ -262,7 +263,7 @@
 
       h3 {
         font-weight: normal;
-        font-size: 14px;
+        font-size: 1em;
         margin: 5px 0;
         i:not(:first-of-type) {
           margin-left: 10px;
@@ -384,11 +385,11 @@
         }
 
         h1 {
-          font-size: 20px;
+          font-size: 1.429em;
         }
 
         h2 {
-          font-size: 15px;
+          font-size: 1.071em;
           margin-top: 4px;
         }
 
@@ -403,7 +404,7 @@
   .user-stream {
     .excerpt {
       margin: 5px 0;
-      font-size: 13px;
+      font-size: 0.929em;
       word-wrap: break-word;
       color: $primary;
     }
@@ -437,7 +438,7 @@
       font-size: 11px;
     }
     .delete-info i {
-      font-size: 14px;
+      font-size: 1em;
     }
     .avatar-link {
       float: left;
@@ -445,7 +446,7 @@
     }
     .title {
       display: block;
-      font-size: 14px;
+      font-size: 1em;
       max-width: 80%;
       white-space: nowrap;
       overflow: hidden;
@@ -453,7 +454,7 @@
     }
     .name {
       display: inline-block;
-      font-size: 14px;
+      font-size: 1em;
       max-width: 400px;
       white-space: nowrap;
       overflow: hidden;
@@ -489,7 +490,7 @@
       // common/base/header.scss
       .fa, .icon {
         color: scale-color($primary, $lightness: 50%);
-        font-size: 24px;
+        font-size: 1.714em;
       }
     }
   }
diff --git a/app/assets/stylesheets/embed.css.scss b/app/assets/stylesheets/embed.css.scss
index 03c01ea4690..6aa22e1e9c7 100644
--- a/app/assets/stylesheets/embed.css.scss
+++ b/app/assets/stylesheets/embed.css.scss
@@ -40,7 +40,7 @@ article.post {
   .post-date {
     float: right;
     color: #aaa;
-    font-size: 12px;
+    font-size: 0.857em;
     margin: 10px 4px 0 0;
   }
 
@@ -54,7 +54,7 @@ article.post {
   }
 
   h3.username {
-    font-size: 13px;
+    font-size: 0.929em;
     margin: 0 0 10px 0;
 
     a {
@@ -104,7 +104,7 @@ img.emoji {
 }
 
 .in-reply-to {
-  font-size: 13px;
+  font-size: 0.929em;
   text-align: center;
   margin: 10px 20px 6px 0;
   display: inline-block;
@@ -113,18 +113,18 @@ img.emoji {
 }
 
 .replies {
-  font-size: 15px;
+  font-size: 1.071em;
   color: #999;
 }
 
 header.embedded {
   padding: 10px 10px 20px 10px;
-  font-size: 18px;
+  font-size: 1.286em;
   border-bottom: 1px solid #ddd;
 }
 
 footer {
-  font-size: 18px;
+  font-size: 1.286em;
 
   .logo {
     margin-right: 10px;
diff --git a/app/assets/stylesheets/mobile/compose.scss b/app/assets/stylesheets/mobile/compose.scss
index 463d4b90625..9255ef577a0 100644
--- a/app/assets/stylesheets/mobile/compose.scss
+++ b/app/assets/stylesheets/mobile/compose.scss
@@ -32,7 +32,7 @@ display: none !important; // can be removed if inline JS CSS is removed from com
   }
   #file-uploading {
     left: 51%;
-    font-size: 12px;
+    font-size: 0.857em;
     color: scale-color($secondary, $lightness: 50%);
   }
   #draft-status {
@@ -47,13 +47,13 @@ display: none !important; // can be removed if inline JS CSS is removed from com
   height: 0;
   background-color: scale-color-diff();
   bottom: 0;
-  font-size: 14px;
+  font-size: 1em;
   position: fixed;
   .toggler {
     width: 15px;
     right: 1px;
     position: absolute;
-    font-size: 15px;
+    font-size: 1.071em;
     color: scale-color($primary, $lightness: 50%);
     padding: 0 10px 5px 10px;
     &:before {
diff --git a/app/assets/stylesheets/mobile/discourse.scss b/app/assets/stylesheets/mobile/discourse.scss
index 7cf2887525e..14a80c6aa8e 100644
--- a/app/assets/stylesheets/mobile/discourse.scss
+++ b/app/assets/stylesheets/mobile/discourse.scss
@@ -23,7 +23,7 @@ body {
     }
     a.star {
       display: inline-block;
-      font-size: 20px;
+      font-size: 1.429em;
       color: scale-color($primary, $lightness: 75%);
       margin-right: 8px;
       margin-top: 4px;
@@ -90,7 +90,7 @@ blockquote {
   vertical-align: middle;
   .topic-status {
     i {
-      font-size: 20px;
+      font-size: 1.429em;
       color: dark-light-diff($secondary, $primary, 40%, -20%);
     }
   }
diff --git a/app/assets/stylesheets/mobile/header.scss b/app/assets/stylesheets/mobile/header.scss
index adfb6888be2..ac05beeb1ff 100644
--- a/app/assets/stylesheets/mobile/header.scss
+++ b/app/assets/stylesheets/mobile/header.scss
@@ -44,7 +44,7 @@
   .heading {
     color: $primary;
     font-weight: bold;
-    font-size: 12px;
+    font-size: 0.857em;
     line-height: 15px;
   }
 
@@ -58,7 +58,7 @@
   
   input[type='text'] {
     width: 265px;
-    font-size: 16px;
+    font-size: 1.143em;
   }
 
   &#user-dropdown {
@@ -78,7 +78,7 @@
 }
 
 .search-link .topic-statuses .topic-status i {
-  font-size: 14px;
+  font-size: 1em;
 }
 
 .d-dropdown#search-dropdown .heading {
diff --git a/app/assets/stylesheets/mobile/login.scss b/app/assets/stylesheets/mobile/login.scss
index 3c6275d0804..6093849bfe4 100644
--- a/app/assets/stylesheets/mobile/login.scss
+++ b/app/assets/stylesheets/mobile/login.scss
@@ -2,7 +2,7 @@
 
 .btn-social {
   width: 250px;
-  font-size: 16px;
+  font-size: 1.143em;
 }
 
 #login-buttons {
@@ -17,7 +17,7 @@
     color: scale-color($primary, $lightness: 35%);
   }
   label { float: left; display: block; }
-  textarea, input, select {font-size: 16px; clear: left; margin-top: 0; }
+  textarea, input, select {font-size: 1.143em; clear: left; margin-top: 0; }
   td { padding: 4px; }
 }
 
diff --git a/app/assets/stylesheets/mobile/modal.scss b/app/assets/stylesheets/mobile/modal.scss
index 5a7ac1c4903..8c94edf25cd 100644
--- a/app/assets/stylesheets/mobile/modal.scss
+++ b/app/assets/stylesheets/mobile/modal.scss
@@ -58,14 +58,14 @@
     display:none;
   }
   h3 {
-    font-size: 18px;
+    font-size: 1.286em;
     padding-left: 15px;
     margin-bottom: 5px;
   }
 }
 .close {
   float: right;
-  font-size: 24px;
+  font-size: 1.714em;
   padding: 10px 15px 5px 5px;
   margin: -15px 0 0 0;
   color: $primary;
@@ -173,7 +173,7 @@
 
 #search-help h2 {
   margin: 0;
-  font-size: 12px;
+  font-size: 0.857em;
 }
 
 #search-help p {
diff --git a/app/assets/stylesheets/mobile/topic-list.scss b/app/assets/stylesheets/mobile/topic-list.scss
index 875426507c5..be58b274752 100644
--- a/app/assets/stylesheets/mobile/topic-list.scss
+++ b/app/assets/stylesheets/mobile/topic-list.scss
@@ -161,7 +161,7 @@ tr.category-topic-link:nth-of-type(odd) {
       margin: 3px 7px 0 0;
       color: scale-color($primary, $lightness: 10%);
       font-weight: bold;
-      font-size: 12px;
+      font-size: 0.857em;
     }
     figcaption {
       display: inline;
diff --git a/app/assets/stylesheets/mobile/topic-post.scss b/app/assets/stylesheets/mobile/topic-post.scss
index 82d0c8c2f16..9ca761c2ba1 100644
--- a/app/assets/stylesheets/mobile/topic-post.scss
+++ b/app/assets/stylesheets/mobile/topic-post.scss
@@ -28,7 +28,7 @@ nav.post-controls {
 
 button {
   border: none;
-  font-size: 17px;
+  font-size: 1.214em;
   padding: 8px 10px;
   vertical-align: top;
   background: transparent;
@@ -167,7 +167,7 @@ a.star {
     margin: 0 0 3px 0;
     color: $primary;
     font-weight: normal;
-    font-size: 12px;
+    font-size: 0.857em;
     line-height: 15px;
   }
 
@@ -282,7 +282,7 @@ a.star {
       }
       .fa {
         margin: 0;
-        font-size: 18px;
+        font-size: 1.286em;
         line-height: 52px;
       }
     }
@@ -308,12 +308,12 @@ a.star {
     }
 
    a.badge-category, a.badge-category-parent {
-    font-size: 10px;
+    font-size: 0.714em;
     vertical-align: top;
     }
 
    .title {
-    font-size: 14px; line-height: 8px;
+    font-size: 1em; line-height: 8px;
   }
 
 }
@@ -416,7 +416,7 @@ background-color: scale-color($danger, $lightness: 75%);
 }
 
 .deleted-user-avatar {
-  font-size: 36px;
+  font-size: 2.571em;
 }
 
 span.btn-text {display: none;}
@@ -470,7 +470,7 @@ span.highlighted {
   }
   .post-info {
     float: right;
-    font-size: 13px;
+    font-size: 0.929em;
     margin: 4px 10px 0 0;
     .edits { margin-right: 5px; }
   }
diff --git a/app/assets/stylesheets/mobile/topic.scss b/app/assets/stylesheets/mobile/topic.scss
index 988a4314280..70812a772f7 100644
--- a/app/assets/stylesheets/mobile/topic.scss
+++ b/app/assets/stylesheets/mobile/topic.scss
@@ -79,7 +79,7 @@
       display: block;
       margin-top: 2px;
       margin-bottom: 2px;
-      font-size: 18px;
+      font-size: 1.286em;
     }
   }
   .jump-form {
@@ -88,7 +88,7 @@
       width: 45px;
       height: 20px;
       text-align: center;
-      font-size: 16px;
+      font-size: 1.143em;
     }
     button.btn {
       float: right !important;
@@ -125,7 +125,7 @@
   }
   h4 {
     display: inline;
-    font-size: 18px;
+    font-size: 1.286em;
     line-height: 15px;
   }
   i.fa {
@@ -149,7 +149,7 @@
   width: 90%;
   margin-left: auto;
   margin-right: auto;
-  font-size: 24px;
+  font-size: 1.714em;
   line-height: 1.1em;
 
   .topic-retry {
diff --git a/app/assets/stylesheets/mobile/upload.scss b/app/assets/stylesheets/mobile/upload.scss
index 5c61b6fcf27..d639f20dbd7 100644
--- a/app/assets/stylesheets/mobile/upload.scss
+++ b/app/assets/stylesheets/mobile/upload.scss
@@ -3,7 +3,7 @@
     width: 520px;
   }
   input[type="file"] {
-    font-size: 14px;
+    font-size: 1em;
     line-height: 18px;
   }
   .description {
diff --git a/app/assets/stylesheets/mobile/user.scss b/app/assets/stylesheets/mobile/user.scss
index f2a47cfabe8..917ea83b6e3 100644
--- a/app/assets/stylesheets/mobile/user.scss
+++ b/app/assets/stylesheets/mobile/user.scss
@@ -236,7 +236,7 @@
 
   .secondary {
     background: dark-light-diff($primary, $secondary, 90%, -65%);
-    font-size: 13px;
+    font-size: 0.929em;
       .btn { padding: 3px 12px; }
 
       dl dd {
@@ -270,13 +270,13 @@
       background-color: rgba($primary, .9);
 
       h1 {
-        font-size: 30px;
+        font-size: 2.143em;
         font-weight: normal;
         margin: 10px 0 0 0;
       }
 
       h2 {
-        font-size: 17px;
+        font-size: 1.214em;
         font-weight: normal;
         margin-top: 10px;
         max-width: 100%;
@@ -287,7 +287,7 @@
 
       h3 {
         font-weight: normal;
-        font-size: 14px;
+        font-size: 1em;
         margin: 5px 0;
         i:not(:first-of-type) {
           margin-left: 10px;
@@ -391,11 +391,11 @@
         }
 
         h1 {
-          font-size: 20px;
+          font-size: 1.429em;
         }
 
         h2 {
-          font-size: 15px;
+          font-size: 1.071em;
           margin-top: 4px;
         }
 
@@ -411,7 +411,7 @@
     padding: 0 10px;
     .excerpt {
       margin: 5px 0;
-      font-size: 13px;
+      font-size: 0.929em;
       word-wrap: break-word;
       color: $primary;
     }
@@ -444,7 +444,7 @@
       font-size: 11px;
     }
     .delete-info i {
-      font-size: 14px;
+      font-size: 1em;
     }
     .avatar-link {
       float: left;
@@ -452,7 +452,7 @@
     }
     .title {
       display: block;
-      font-size: 14px;
+      font-size: 1em;
       max-width: 80%;
       white-space: nowrap;
       overflow: hidden;
@@ -460,7 +460,7 @@
     }
     .name {
       display: inline-block;
-      font-size: 14px;
+      font-size: 1em;
       max-width: 400px;
       white-space: nowrap;
       overflow: hidden;
@@ -496,7 +496,7 @@
       // common/base/header.scss
       .fa, .icon {
         color: scale-color($primary, $lightness: 50%);
-        font-size: 24px;
+        font-size: 1.714em;
       }
     }
   }
diff --git a/app/assets/stylesheets/vendor/bootstrap.scss b/app/assets/stylesheets/vendor/bootstrap.scss
index d5aae10e0c8..d10894e8eda 100644
--- a/app/assets/stylesheets/vendor/bootstrap.scss
+++ b/app/assets/stylesheets/vendor/bootstrap.scss
@@ -169,7 +169,7 @@ body {
   }
 
   p, pre, li, ul {
-    font-size: 14px;
+    font-size: 1em;
   }
   p {
     line-height: 20px;
@@ -186,25 +186,25 @@ body {
     color: inherit;
   }
   h1 {
-    font-size: 30px;
+    font-size: 2.143em;
     line-height: 36px;
   }
   h2 {
-    font-size: 24px;
+    font-size: 1.714em;
     line-height: 36px;
   }
   h3 {
-    font-size: 18px;
+    font-size: 1.286em;
     line-height: 27px;
   }
   h4, h5, h6 {
     line-height: 18px;
   }
   h4 {
-    font-size: 14px;
+    font-size: 1em;
   }
   h5 {
-    font-size: 12px;
+    font-size: 0.857em;
   }
   h6 {
     font-size: 11px;
@@ -226,7 +226,7 @@ body {
     margin: 0 0 18px;
   }
   label, input, button, select, textarea {
-    font-size: 13px;
+    font-size: 0.929em;
     font-weight: normal;
     line-height: 18px;
   }
@@ -241,7 +241,7 @@ body {
     display: inline-block;
     padding: 4px;
     margin-bottom: 9px;
-    font-size: 13px;
+    font-size: 0.929em;
     line-height: 18px;
     color: #555555;
   }
@@ -251,7 +251,7 @@ body {
       height: 18px;
       padding: 4px;
       margin-bottom: 9px;
-      font-size: 13px;
+      font-size: 0.929em;
       line-height: 18px;
       color: #555555;
     }
@@ -580,7 +580,7 @@ body {
   .alert {
     .close {
       float: right;
-      font-size: 20px;
+      font-size: 1.429em;
       font-weight: bold;
       line-height: 18px;
       color: black;