diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -12,7 +12,11 @@
     'core.pkg.css' => '3471f5d3',
     'core.pkg.js' => '2eeda9e0',
     'dark-console.pkg.js' => '187792c2',
+<<<<<<< HEAD
     'differential.pkg.css' => '6d3700f0',
+=======
+    'differential.pkg.css' => 'c570bd80',
+>>>>>>> 239880da4c (Workboard: have thin scrollbars)
     'differential.pkg.js' => '46fcb3af',
     'diffusion.pkg.css' => '354279ea',
     'diffusion.pkg.js' => '78c9885d',
@@ -155,8 +159,13 @@
     'rsrc/css/phui/phui-feed-story.css' => 'a0c05029',
     'rsrc/css/phui/phui-fontkit.css' => '1ec937e5',
     'rsrc/css/phui/phui-form-view.css' => '57edecb7',
+<<<<<<< HEAD
     'rsrc/css/phui/phui-form.css' => '1f177cb7',
     'rsrc/css/phui/phui-formation-view.css' => 'd2dec8ed',
+=======
+    'rsrc/css/phui/phui-form.css' => 'd1adb52c',
+    'rsrc/css/phui/phui-formation-view.css' => '1338d245',
+>>>>>>> 239880da4c (Workboard: have thin scrollbars)
     'rsrc/css/phui/phui-head-thing.css' => 'd7f293df',
     'rsrc/css/phui/phui-header-view.css' => '36c86a58',
     'rsrc/css/phui/phui-hovercard.css' => '39fd2e14',
@@ -181,9 +190,9 @@
     'rsrc/css/phui/phui-timeline-view.css' => '7f8659ec',
     'rsrc/css/phui/phui-two-column-view.css' => 'f96d319f',
     'rsrc/css/phui/workboards/phui-workboard-color.css' => '3a1c21ff',
-    'rsrc/css/phui/workboards/phui-workboard.css' => '74fc9d98',
+    'rsrc/css/phui/workboards/phui-workboard.css' => 'e3fdb31d',
     'rsrc/css/phui/workboards/phui-workcard.css' => '62056e3b',
-    'rsrc/css/phui/workboards/phui-workpanel.css' => 'bc06f022',
+    'rsrc/css/phui/workboards/phui-workpanel.css' => 'cc343387',
     'rsrc/css/sprite-login.css' => '07052ee0',
     'rsrc/css/sprite-tokens.css' => 'f1896dc5',
     'rsrc/css/syntax/syntax-default.css' => 'c0307dc6',
@@ -849,7 +858,7 @@
     'phui-fontkit-css' => '1ec937e5',
     'phui-form-css' => '1f177cb7',
     'phui-form-view-css' => '57edecb7',
-    'phui-formation-view-css' => 'd2dec8ed',
+    'phui-formation-view-css' => '1338d245',
     'phui-head-thing-view-css' => 'd7f293df',
     'phui-header-view-css' => '36c86a58',
     'phui-hovercard' => '6199f752',
@@ -884,9 +893,9 @@
     'phui-timeline-view-css' => '7f8659ec',
     'phui-two-column-view-css' => 'f96d319f',
     'phui-workboard-color-css' => '3a1c21ff',
-    'phui-workboard-view-css' => '74fc9d98',
+    'phui-workboard-view-css' => 'e3fdb31d',
     'phui-workcard-view-css' => '62056e3b',
-    'phui-workpanel-view-css' => 'bc06f022',
+    'phui-workpanel-view-css' => 'cc343387',
     'phuix-action-list-view' => 'c68f183f',
     'phuix-action-view' => 'a8f573a9',
     'phuix-autocomplete' => '2fbe234d',
@@ -2007,9 +2016,6 @@
       'javelin-uri',
       'phabricator-notification',
     ),
-    'bc06f022' => array(
-      'phui-workcard-view-css',
-    ),
     'c03f2fb4' => array(
       'javelin-install',
     ),
@@ -2069,6 +2075,9 @@
       'phuix-button-view',
       'phabricator-diff-tree-view',
     ),
+    'cc343387' => array(
+      'phui-workcard-view-css',
+    ),
     'cef53b3e' => array(
       'javelin-install',
       'javelin-dom',
diff --git a/webroot/rsrc/css/phui/phui-formation-view.css b/webroot/rsrc/css/phui/phui-formation-view.css
--- a/webroot/rsrc/css/phui/phui-formation-view.css
+++ b/webroot/rsrc/css/phui/phui-formation-view.css
@@ -147,6 +147,12 @@
   overflow: hidden auto;
 }
 
+.device-desktop .phui-flank-view-fixed .phui-flank-view-body {
+  scrollbar-width: thin;
+}
+
+/* Alternative thin scrollbar when `scrollbar-width: thin` is not supported */
+/* (Use the same selector as above for consistent behavior on Chrome/Firefox) */
 .device-desktop .phui-flank-view-fixed
   .phui-flank-view-body::-webkit-scrollbar {
   height: 6px;
diff --git a/webroot/rsrc/css/phui/workboards/phui-workboard.css b/webroot/rsrc/css/phui/workboards/phui-workboard.css
--- a/webroot/rsrc/css/phui/workboards/phui-workboard.css
+++ b/webroot/rsrc/css/phui/workboards/phui-workboard.css
@@ -21,6 +21,12 @@
   padding: 16px;
 }
 
+.phui-workboard-view-shadow {
+  scrollbar-width: thin;
+}
+
+/* Alternative thin scrollbar when `scrollbar-width: thin` is not supported */
+/* (Use the same selector as above for consistent behavior on Chrome/Firefox) */
 .phui-workboard-view-shadow::-webkit-scrollbar {
   height: 8px;
   width: 8px;
diff --git a/webroot/rsrc/css/phui/workboards/phui-workpanel.css b/webroot/rsrc/css/phui/workboards/phui-workpanel.css
--- a/webroot/rsrc/css/phui/workboards/phui-workpanel.css
+++ b/webroot/rsrc/css/phui/workboards/phui-workpanel.css
@@ -95,11 +95,14 @@
 }
 
 .device-desktop .phui-workpanel-body-content {
+  scrollbar-width: thin;
   max-height: calc(100vh - 162px);
   overflow-y: auto;
   overflow-x: hidden;
 }
 
+/* Alternative thin scrollbar when `scrollbar-width: thin` is not supported */
+/* (Use the same selector as above for consistent behavior on Chrome/Firefox) */
 .device-desktop .phui-workpanel-body-content::-webkit-scrollbar {
   height: 8px;
   width: 8px;