diff --git a/app/assets/stylesheets/common/base/discourse.scss b/app/assets/stylesheets/common/base/discourse.scss
index c47540f1447..fb3825c5f6e 100644
--- a/app/assets/stylesheets/common/base/discourse.scss
+++ b/app/assets/stylesheets/common/base/discourse.scss
@@ -47,11 +47,11 @@ body {
 }
 
 big {
-  font-size: 28px;
+  font-size: 2em;
 }
 
 small {
-  font-size: 9px;
+  font-size: .643em;
 }
 
 //setting a static limit on big and small prevents nesting abuse
diff --git a/app/assets/stylesheets/common/base/exception.scss b/app/assets/stylesheets/common/base/exception.scss
index 9bdc0df4bb8..312e87da1e4 100644
--- a/app/assets/stylesheets/common/base/exception.scss
+++ b/app/assets/stylesheets/common/base/exception.scss
@@ -3,7 +3,7 @@
   padding-top: 2em;
 
   .face {
-    font-size: 60px;
+    font-size: 4.286em;
     height: 60px;
   }
   .reason {
@@ -12,7 +12,7 @@
   }
   .url {
     font-style: italic;
-    font-size: 11px;
+    font-size: .786em;
   }
   .desc {
     margin-top: 16px;
diff --git a/app/assets/stylesheets/common/base/menu-panel.scss b/app/assets/stylesheets/common/base/menu-panel.scss
index 71a747989c8..2aef0117e00 100644
--- a/app/assets/stylesheets/common/base/menu-panel.scss
+++ b/app/assets/stylesheets/common/base/menu-panel.scss
@@ -90,7 +90,7 @@
   b.topics-count {
     color: dark-light-choose($primary-medium, $secondary-medium);
     font-weight: normal;
-    font-size: 11px;
+    font-size: .786em;
   }
 
   span.badge-category {
diff --git a/app/assets/stylesheets/common/base/modal.scss b/app/assets/stylesheets/common/base/modal.scss
index 61368c83084..48a8f67824f 100644
--- a/app/assets/stylesheets/common/base/modal.scss
+++ b/app/assets/stylesheets/common/base/modal.scss
@@ -180,7 +180,7 @@
           color: rgb(255,255,255);
           position: absolute;
           top: 40%;
-          font-size: 36px;
+          font-size: 2.571em;
           text-align: center;
           line-height: 38px;
           margin-left: auto;
@@ -197,7 +197,7 @@
       .jsfu-separator {
         vertical-align: middle;
         display: table-cell;
-        font-size: 36px;
+        font-size: 2.571em;
         padding-left: 10px;
         padding-right: 10px;
       }
@@ -225,7 +225,7 @@
 
   // password reset modal
   .modal-body.forgot-password-modal p {
-    font-size: 14px;
+    font-size: 1em;
   }
 }
 
diff --git a/app/assets/stylesheets/common/base/onebox.scss b/app/assets/stylesheets/common/base/onebox.scss
index ad91cb24b25..2d68e3a9265 100644
--- a/app/assets/stylesheets/common/base/onebox.scss
+++ b/app/assets/stylesheets/common/base/onebox.scss
@@ -270,7 +270,7 @@ pre.onebox code ol.lines li:before {
   color:#AFAFAF;
   text-align:right;
   padding-right:5px;
-  font-size:12px;
+  font-size:.857em;
   line-height: 1.9em;
   content: counter(li-counter);
   counter-increment: li-counter;
@@ -331,7 +331,7 @@ pre.onebox code {
 .onebox-body .build_status
 {
   padding: 2px;
-  font-size:12px;
+  font-size:.857em;
 }
 
 .onebox-body .status_tag.open {
@@ -379,7 +379,7 @@ aside.onebox.twitterstatus .onebox-body {
     z-index: 935;
     height: 30px;
     overflow: hidden;
-    font-size: 12px;
+    font-size: .857em;
     color: #fff;
     background-color: rgba(0, 0, 0, 0.6);
     text-overflow: ellipsis;
@@ -395,7 +395,7 @@ aside.onebox.twitterstatus .onebox-body {
 
       .album-title {
         width: 100%;
-        font-size: 13px;
+        font-size: 1.083em;
         line-height: 30px;
         color: #ccc;
         text-decoration: none;
diff --git a/app/assets/stylesheets/common/base/search.scss b/app/assets/stylesheets/common/base/search.scss
index ca154cefc58..b5a29fba5dc 100644
--- a/app/assets/stylesheets/common/base/search.scss
+++ b/app/assets/stylesheets/common/base/search.scss
@@ -11,7 +11,7 @@
 
   .like-count {
     color: dark-light-choose($primary-medium, $secondary-medium);
-    .fa { color: $love; font-size: 12px; }
+    .fa { color: $love; font-size: .857em; }
   }
 
   .badge-wrapper span.badge-category {
@@ -80,7 +80,7 @@
   }
   a {
     margin-right: 15px;
-    font-size: 12px;
+    font-size: .857em;
     padding: 2px 5px;
   }
 }
diff --git a/app/assets/stylesheets/common/base/share_link.scss b/app/assets/stylesheets/common/base/share_link.scss
index 10ba75d1109..00cf0ca4269 100644
--- a/app/assets/stylesheets/common/base/share_link.scss
+++ b/app/assets/stylesheets/common/base/share_link.scss
@@ -31,7 +31,7 @@
     color: $success;
     opacity: 1;
     transition: opacity 0.25s;
-    font-size: 13px;
+    font-size: .929em;
     &:not(.success) {
       opacity: 0;
     }
diff --git a/app/assets/stylesheets/common/base/tagging.scss b/app/assets/stylesheets/common/base/tagging.scss
index ef366d102f9..6eb3d47d468 100644
--- a/app/assets/stylesheets/common/base/tagging.scss
+++ b/app/assets/stylesheets/common/base/tagging.scss
@@ -35,8 +35,8 @@
 .bullet + .topic-header-extra {
   display: block;
   line-height: 15px;
-  font-size: 12px;
-  .list-tags { font-size: 12px; }
+  font-size: .857em;
+  .list-tags { font-size: 1em; }
 }
 
 .bar + .topic-header-extra {
diff --git a/app/assets/stylesheets/common/base/topic-post.scss b/app/assets/stylesheets/common/base/topic-post.scss
index 6151d863399..e964fd720f7 100644
--- a/app/assets/stylesheets/common/base/topic-post.scss
+++ b/app/assets/stylesheets/common/base/topic-post.scss
@@ -34,7 +34,7 @@
    }
  }
  .fa {
-   font-size: 11px;
+   font-size: .786em;
    margin-left: 3px;
    color: dark-light-choose($primary-medium, $secondary-medium);
  }
@@ -204,7 +204,7 @@ aside.quote {
     right: -4px;
   }
   .fa {
-    font-size: 24px;
+    font-size: 1.714em;
   }
 }
 .topic-map .poster .avatar-flair {
@@ -222,7 +222,7 @@ aside.quote {
     right: 0;
   }
   .fa {
-    font-size: 14px;
+    font-size: 1em;
   }
 }
 .topic-avatar .poster-avatar-extra {
@@ -351,7 +351,7 @@ blockquote > *:last-child {
     border-top: none;
     float: left;
     i {
-      font-size: 35px;
+      font-size: 2.500em;
       width: 45px;
       text-align: center;
       color: dark-light-choose($primary-low-mid, $secondary-high);
@@ -378,7 +378,7 @@ blockquote > *:last-child {
       text-transform: none;
       margin: 15px 0px 5px;
       font-weight: normal;
-      font-size: 14px;
+      font-size: 1.11em;
       p {
         margin: 5px 0;
       }
@@ -479,7 +479,7 @@ a.mention, a.mention-group {
 .broken-image, .large-image {
   color: dark-light-choose($primary-low-mid, $secondary-high);
   border: 1px solid $primary-low;
-  font-size: 32px;
+  font-size: 2.286em;
   padding: 16px;
 }
 
diff --git a/app/assets/stylesheets/common/base/username_tagsinput.scss b/app/assets/stylesheets/common/base/username_tagsinput.scss
index c18494c18c1..66e5b32ea1a 100644
--- a/app/assets/stylesheets/common/base/username_tagsinput.scss
+++ b/app/assets/stylesheets/common/base/username_tagsinput.scss
@@ -20,10 +20,10 @@ div.tagsinput span.tag {
   margin-right: 5px;
   margin-bottom:5px;
   font-family: helvetica;
-  font-size:13px;
+  font-size: .929em;
 }
 
-div.tagsinput span.tag a { font-weight: bold; color: #82ad2b; text-decoration:none; font-size: 11px;  }
+div.tagsinput span.tag a { font-weight: bold; color: #82ad2b; text-decoration:none; font-size: .786em;  }
 div.tagsinput input {
   width:80px;
   font-family: helvetica;
diff --git a/app/assets/stylesheets/common/components/badges.scss b/app/assets/stylesheets/common/components/badges.scss
index c9ccb9fecf1..b988ed40943 100644
--- a/app/assets/stylesheets/common/components/badges.scss
+++ b/app/assets/stylesheets/common/components/badges.scss
@@ -60,7 +60,7 @@
     display: inline-flex;
     align-items: baseline;
     margin-right: 5px;
-    font-size: 12px;
+    font-size: .857em;
     line-height: 15px;
 
     span.badge-category {
@@ -251,7 +251,7 @@
   padding: 4px 5px 2px 5px;
   vertical-align: middle;
   color: $secondary;
-  font-size: 11px;
+  font-size: .786em;
   line-height: 1;
   text-align: center;
   background-color: dark-light-choose($primary-low-mid, $secondary-low);
diff --git a/app/assets/stylesheets/common/components/buttons.scss b/app/assets/stylesheets/common/components/buttons.scss
index e339fa26077..a3ce89e5c94 100644
--- a/app/assets/stylesheets/common/components/buttons.scss
+++ b/app/assets/stylesheets/common/components/buttons.scss
@@ -127,7 +127,7 @@
   &:before {
     margin-right: 9px;
     font-family: FontAwesome;
-    font-size: 17px;
+    font-size: 1.214em;
   }
   &.google, &.google_oauth2 {
     background: $google;
diff --git a/app/assets/stylesheets/common/components/user-info.scss b/app/assets/stylesheets/common/components/user-info.scss
index 5a2dcd33597..b6e0b71ad12 100644
--- a/app/assets/stylesheets/common/components/user-info.scss
+++ b/app/assets/stylesheets/common/components/user-info.scss
@@ -13,7 +13,7 @@
     float: left;
     width: 70%;
     padding-left: 5px;
-    font-size: 13px;
+    font-size: .929em;
 
     .name-line {
       white-space: nowrap;
diff --git a/app/assets/stylesheets/common/components/user-stream-item.scss b/app/assets/stylesheets/common/components/user-stream-item.scss
index 57fd7ab4da9..ef31dfbe1ce 100644
--- a/app/assets/stylesheets/common/components/user-stream-item.scss
+++ b/app/assets/stylesheets/common/components/user-stream-item.scss
@@ -36,7 +36,7 @@
     display: block;
     float: right;
     color: lighten($primary, 40%);
-    font-size: 11px;
+    font-size: .786em;
   }
 
   .delete-info i {
diff --git a/app/assets/stylesheets/common/select-kit/category-chooser.scss b/app/assets/stylesheets/common/select-kit/category-chooser.scss
index ed4417f96ae..62da15be23f 100644
--- a/app/assets/stylesheets/common/select-kit/category-chooser.scss
+++ b/app/assets/stylesheets/common/select-kit/category-chooser.scss
@@ -21,7 +21,7 @@
         }
 
         .topic-count {
-          font-size: 11px;
+          font-size: .786em;
           color: $primary;
         }
 
diff --git a/app/assets/stylesheets/common/select-kit/future-date-input-selector.scss b/app/assets/stylesheets/common/select-kit/future-date-input-selector.scss
index 05771bb9d37..333b21d060c 100644
--- a/app/assets/stylesheets/common/select-kit/future-date-input-selector.scss
+++ b/app/assets/stylesheets/common/select-kit/future-date-input-selector.scss
@@ -5,7 +5,7 @@
 
       .future-date-input-selector-datetime {
         color: lighten($primary, 40%);
-        font-size: 13px;
+        font-size: .929em;
       }
 
       .future-date-input-selector-icons {
diff --git a/app/assets/stylesheets/common/select-kit/legacy-combo-box.scss b/app/assets/stylesheets/common/select-kit/legacy-combo-box.scss
index 96c2682242d..4f8aeb70bdd 100644
--- a/app/assets/stylesheets/common/select-kit/legacy-combo-box.scss
+++ b/app/assets/stylesheets/common/select-kit/legacy-combo-box.scss
@@ -10,7 +10,7 @@
     display: inline-block;
   }
   .topic-count {
-    font-size: 11px;
+    font-size: .786em;
     color: $primary;
     display: inline-block;
   }
diff --git a/app/assets/stylesheets/common/select-kit/multi-select.scss b/app/assets/stylesheets/common/select-kit/multi-select.scss
index e5cbf2c2a9a..f841e4644fe 100644
--- a/app/assets/stylesheets/common/select-kit/multi-select.scss
+++ b/app/assets/stylesheets/common/select-kit/multi-select.scss
@@ -159,7 +159,7 @@
           .d-icon {
             color: $primary-medium;
             cursor: pointer;
-            font-size: 14px;
+            font-size: 1em;
 
             &:hover {
               color: $primary;
diff --git a/app/assets/stylesheets/desktop/header.scss b/app/assets/stylesheets/desktop/header.scss
index 9417b848090..9a7f7ce4ab1 100644
--- a/app/assets/stylesheets/desktop/header.scss
+++ b/app/assets/stylesheets/desktop/header.scss
@@ -34,7 +34,7 @@ and (max-width : 570px) {
   color: dark-light-choose($primary-high, $secondary-medium);
   display: block;
   word-wrap: break-word;
-  font-size: 11px;
+  font-size: .786em;
   line-height: 1.3em;
   .search-highlight {
     color: dark-light-choose($primary-high, $secondary-low);
diff --git a/app/assets/stylesheets/desktop/topic-list.scss b/app/assets/stylesheets/desktop/topic-list.scss
index 963cec5950c..c7abc601de7 100644
--- a/app/assets/stylesheets/desktop/topic-list.scss
+++ b/app/assets/stylesheets/desktop/topic-list.scss
@@ -136,13 +136,13 @@
     width: auto;
     color: dark-light-choose($primary-medium, $secondary-medium);
     text-align: left;
-    font-size: 12px;
+    font-size: .857em;
     margin-top: 5px;
     .fa {
       margin-right: 2px;
     }
     a {
-      font-size: 11px;
+      font-size: 0.917em;
       color: dark-light-choose($primary-medium, $secondary-medium);
       margin-right: 3px;
       line-height: 20px;
diff --git a/app/assets/stylesheets/desktop/topic-post.scss b/app/assets/stylesheets/desktop/topic-post.scss
index 0896c3bc447..579456023b7 100644
--- a/app/assets/stylesheets/desktop/topic-post.scss
+++ b/app/assets/stylesheets/desktop/topic-post.scss
@@ -328,7 +328,7 @@ a.star {
       padding: 4px 5px 2px 5px;
       text-align: center;
       font-weight: normal;
-      font-size: 11px;
+      font-size: .786em;
       line-height: 1;
     }
   }
@@ -473,7 +473,7 @@ a.star {
 #suggested-topics .topic-statuses .topic-status {
   padding: 0;
   i {
-    font-size:15px;
+    font-size:1.071em;
   }
 }
 
diff --git a/app/assets/stylesheets/mobile/directory.scss b/app/assets/stylesheets/mobile/directory.scss
index 4636e391eb0..224a00b3229 100644
--- a/app/assets/stylesheets/mobile/directory.scss
+++ b/app/assets/stylesheets/mobile/directory.scss
@@ -31,7 +31,7 @@
   }
   .user-stat {
     margin-left: 55px;
-    font-size: 13px;
+    font-size: .929em;
 
     .value {
       font-weight: bold;
diff --git a/app/assets/stylesheets/mobile/topic-post.scss b/app/assets/stylesheets/mobile/topic-post.scss
index 5e6cad2d498..c820571309a 100644
--- a/app/assets/stylesheets/mobile/topic-post.scss
+++ b/app/assets/stylesheets/mobile/topic-post.scss
@@ -196,7 +196,7 @@ a.star {
       padding: 4px 5px 2px 5px;
       text-align: center;
       font-weight: normal;
-      font-size: 11px;
+      font-size: .786em;
       line-height: 1;
     }
   }
diff --git a/app/assets/stylesheets/wizard.scss b/app/assets/stylesheets/wizard.scss
index 1da624bfb5f..656b5006a92 100644
--- a/app/assets/stylesheets/wizard.scss
+++ b/app/assets/stylesheets/wizard.scss
@@ -171,7 +171,7 @@ body.wizard {
 
     span {
       position: absolute;
-      font-size: 15px;
+      font-size: 1.071em;
       mix-blend-mode: difference;
       color: white;
       z-index: 13;