diff --git a/resources/celerity/map.php b/resources/celerity/map.php
index 155238df48..4cdcb9c0c9 100644
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -7,7 +7,7 @@
  */
 return array(
   'names' => array(
-    'core.pkg.css' => '5ca11af3',
+    'core.pkg.css' => 'f1ac6066',
     'core.pkg.js' => '59d01bb7',
     'darkconsole.pkg.js' => '6d16ff19',
     'differential.pkg.css' => '3500921f',
@@ -108,12 +108,12 @@ return array(
     'rsrc/css/application/tokens/tokens.css' => '3d0f239e',
     'rsrc/css/application/uiexample/example.css' => '528b19de',
     'rsrc/css/core/core.css' => '76e8ee93',
-    'rsrc/css/core/remarkup.css' => 'a59502c9',
+    'rsrc/css/core/remarkup.css' => '9e4a32d9',
     'rsrc/css/core/syntax.css' => '56c1ba38',
     'rsrc/css/core/z-index.css' => '5a2b9d9d',
     'rsrc/css/diviner/diviner-shared.css' => '38813222',
     'rsrc/css/font/font-awesome.css' => 'ae9a7b4d',
-    'rsrc/css/font/font-source-sans-pro.css' => '4a2430d7',
+    'rsrc/css/font/font-source-sans-pro.css' => '8906c07b',
     'rsrc/css/font/phui-font-icon-base.css' => '3dad2ae3',
     'rsrc/css/layout/phabricator-filetree-view.css' => 'fccf9f82',
     'rsrc/css/layout/phabricator-hovercard-view.css' => '44394670',
@@ -131,7 +131,7 @@ return array(
     'rsrc/css/phui/phui-crumbs-view.css' => '594d719e',
     'rsrc/css/phui/phui-document.css' => '94d5dcd8',
     'rsrc/css/phui/phui-feed-story.css' => 'c9f3a0b5',
-    'rsrc/css/phui/phui-fontkit.css' => 'ce228013',
+    'rsrc/css/phui/phui-fontkit.css' => '81ed5e20',
     'rsrc/css/phui/phui-form-view.css' => 'b147d2ed',
     'rsrc/css/phui/phui-form.css' => 'f535f938',
     'rsrc/css/phui/phui-header-view.css' => 'da4586b1',
@@ -162,14 +162,14 @@ return array(
     'rsrc/externals/font/fontawesome/fontawesome-webfont.ttf' => 'a653cb11',
     'rsrc/externals/font/fontawesome/fontawesome-webfont.woff' => '80526fc8',
     'rsrc/externals/font/fontawesome/fontawesome-webfont.woff2' => '4924d54d',
-    'rsrc/externals/font/sourcesans/SourceSansPro-Bold.woff2' => '165f5f74',
-    'rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff' => 'd09a7d54',
-    'rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff2' => 'd2e33102',
     'rsrc/externals/font/sourcesans/SourceSansPro-It.woff' => '3f21af52',
     'rsrc/externals/font/sourcesans/SourceSansPro-It.woff2' => '30a7cf60',
     'rsrc/externals/font/sourcesans/SourceSansPro-Regular.woff2' => 'e89b04b1',
+    'rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff' => '67cce9ea',
+    'rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff2' => 'ec2ed916',
+    'rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff' => 'bd1ce81d',
+    'rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff2' => 'd9928416',
     'rsrc/externals/font/sourcesans/SourceSansPro.woff' => '3614608c',
-    'rsrc/externals/font/sourcesans/SourceSansProBold.woff' => 'cbf46566',
     'rsrc/externals/javelin/core/Event.js' => '85ea0626',
     'rsrc/externals/javelin/core/Stratcom.js' => '6c53634d',
     'rsrc/externals/javelin/core/__tests__/event-stop-and-kill.js' => '717554e4',
@@ -540,7 +540,7 @@ return array(
     'diffusion-source-css' => '66fdf661',
     'diviner-shared-css' => '38813222',
     'font-fontawesome' => 'ae9a7b4d',
-    'font-source-sans-pro' => '4a2430d7',
+    'font-source-sans-pro' => '8906c07b',
     'global-drag-and-drop-css' => '697324ad',
     'harbormaster-css' => '49d64eb4',
     'herald-css' => '826075fa',
@@ -746,7 +746,7 @@ return array(
     'phabricator-phtize' => 'd254d646',
     'phabricator-prefab' => '6920d200',
     'phabricator-profile-css' => '1a20dcbf',
-    'phabricator-remarkup-css' => 'a59502c9',
+    'phabricator-remarkup-css' => '9e4a32d9',
     'phabricator-search-results-css' => '15c71110',
     'phabricator-shaped-request' => '7cbe244b',
     'phabricator-side-menu-view-css' => '7e8c6341',
@@ -789,7 +789,7 @@ return array(
     'phui-document-view-css' => '94d5dcd8',
     'phui-feed-story-css' => 'c9f3a0b5',
     'phui-font-icon-base-css' => '3dad2ae3',
-    'phui-fontkit-css' => 'ce228013',
+    'phui-fontkit-css' => '81ed5e20',
     'phui-form-css' => 'f535f938',
     'phui-form-view-css' => 'b147d2ed',
     'phui-header-view-css' => 'da4586b1',
@@ -1165,9 +1165,6 @@ return array(
       'javelin-request',
       'javelin-util',
     ),
-    '4a2430d7' => array(
-      'phui-fontkit-css',
-    ),
     '4d94d9c3' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1515,6 +1512,9 @@ return array(
       'javelin-dom',
       'javelin-vector',
     ),
+    '8906c07b' => array(
+      'phui-fontkit-css',
+    ),
     '8a41885b' => array(
       'javelin-install',
       'javelin-dom',
diff --git a/webroot/rsrc/css/core/remarkup.css b/webroot/rsrc/css/core/remarkup.css
index 053f5849ca..7ed94e1fc5 100644
--- a/webroot/rsrc/css/core/remarkup.css
+++ b/webroot/rsrc/css/core/remarkup.css
@@ -95,37 +95,37 @@
 }
 
 .phabricator-remarkup h1.remarkup-header {
-  font-size: 1.625em;
+  font-size: 24px;
   line-height: 1.625em;
   margin: 16px 0 4px;
 }
 
 .phabricator-remarkup h2.remarkup-header {
-  font-size: 1.5em;
+  font-size: 20px;
   line-height: 1.5em;
   margin: 16px 0 4px;
 }
 
 .phabricator-remarkup h3.remarkup-header {
-  font-size: 1.375em;
+  font-size: 18px;
   line-height: 1.375em;
   margin: 16px 0 4px;
 }
 
 .phabricator-remarkup h4.remarkup-header {
-  font-size: 1.25em;
+  font-size: 15px;
   line-height: 1.25em;
   margin: 8px 0 4px;
 }
 
 .phabricator-remarkup h5.remarkup-header {
-  font-size: 1.125em;
+  font-size: 14px;
   line-height: 1.125em;
   margin: 4px 0;
 }
 
 .phabricator-remarkup h6.remarkup-header {
-  font-size: 1em;
+  font-size: 13px;
   line-height: 1em;
   margin: 4px 0;
 }
diff --git a/webroot/rsrc/css/font/font-source-sans-pro.css b/webroot/rsrc/css/font/font-source-sans-pro.css
index 4576b1ae9f..65ff2491a5 100644
--- a/webroot/rsrc/css/font/font-source-sans-pro.css
+++ b/webroot/rsrc/css/font/font-source-sans-pro.css
@@ -18,12 +18,12 @@
 @font-face {
   font-family: 'Source Sans Pro';
   font-style: normal;
-  font-weight: 700;
-  src: local('Source Sans Pro Bold'),
-       local('SourceSansPro-Bold'),
-       url(/rsrc/externals/font/sourcesans/SourceSansPro-Bold.woff2)
+  font-weight: 600;
+  src: local('Source Sans Pro Semibold'),
+       local('SourceSansPro-Semibold'),
+       url(/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff2)
         format('woff2'),
-       url(/rsrc/externals/font/sourcesans/SourceSansProBold.woff)
+       url(/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff)
         format('woff');
 }
 
@@ -45,10 +45,10 @@
     font-weight: 700;
     font-style: italic;
     font-stretch: normal;
-    src: local('Source Sans Pro Bold It'),
-         local('SourceSansPro-BoldIt'),
-         url(/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff2)
+    src: local('Source Sans Pro Semibold It'),
+         local('SourceSansPro-SemiboldIt'),
+         url(/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff2)
           format('woff'),
-         url(/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff)
+         url(/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff)
           format('woff');
 }
diff --git a/webroot/rsrc/css/phui/phui-fontkit.css b/webroot/rsrc/css/phui/phui-fontkit.css
index 638e1d38d5..f7007a3a54 100644
--- a/webroot/rsrc/css/phui/phui-fontkit.css
+++ b/webroot/rsrc/css/phui/phui-fontkit.css
@@ -41,6 +41,7 @@
 .phui-font-source-sans .phabricator-remarkup h5.remarkup-header,
 .phui-font-source-sans .phabricator-remarkup h6.remarkup-header {
   color: {$bluetext};
+  font-weight: 600;
 }
 
 .phui-font-source-sans .phabricator-remarkup h2.remarkup-header {
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Bold.woff2 b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Bold.woff2
deleted file mode 100644
index 9b3351f657..0000000000
Binary files a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Bold.woff2 and /dev/null differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff
deleted file mode 100644
index 97e03c41b3..0000000000
Binary files a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff and /dev/null differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff2 b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff2
deleted file mode 100644
index 4845a9841b..0000000000
Binary files a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-BoldIt.woff2 and /dev/null differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff
new file mode 100644
index 0000000000..f0ac4041d5
Binary files /dev/null and b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff2 b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff2
new file mode 100644
index 0000000000..b7a623825d
Binary files /dev/null and b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-Semibold.woff2 differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff
new file mode 100644
index 0000000000..f9717671dd
Binary files /dev/null and b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff2 b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff2
new file mode 100644
index 0000000000..07fc94945c
Binary files /dev/null and b/webroot/rsrc/externals/font/sourcesans/SourceSansPro-SemiboldIt.woff2 differ
diff --git a/webroot/rsrc/externals/font/sourcesans/SourceSansProBold.woff b/webroot/rsrc/externals/font/sourcesans/SourceSansProBold.woff
deleted file mode 100644
index 12bd5526c9..0000000000
Binary files a/webroot/rsrc/externals/font/sourcesans/SourceSansProBold.woff and /dev/null differ