diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -9,7 +9,7 @@
   'names' => array(
     'conpherence.pkg.css' => '2f25eb4f',
     'conpherence.pkg.js' => '020aebcf',
-    'core.pkg.css' => '3471f5d3',
+    'core.pkg.css' => 'df053593',
     'core.pkg.js' => '2eeda9e0',
     'dark-console.pkg.js' => '187792c2',
     'differential.pkg.css' => '6d3700f0',
@@ -158,7 +158,7 @@
     'rsrc/css/phui/phui-form.css' => '1f177cb7',
     'rsrc/css/phui/phui-formation-view.css' => 'd2dec8ed',
     'rsrc/css/phui/phui-head-thing.css' => 'd7f293df',
-    'rsrc/css/phui/phui-header-view.css' => '36c86a58',
+    'rsrc/css/phui/phui-header-view.css' => '78e4b1ad',
     'rsrc/css/phui/phui-hovercard.css' => '39fd2e14',
     'rsrc/css/phui/phui-icon-set-selector.css' => '19e0253b',
     'rsrc/css/phui/phui-icon.css' => '084ac612',
@@ -851,7 +851,7 @@
     'phui-form-view-css' => '57edecb7',
     'phui-formation-view-css' => 'd2dec8ed',
     'phui-head-thing-view-css' => 'd7f293df',
-    'phui-header-view-css' => '36c86a58',
+    'phui-header-view-css' => '78e4b1ad',
     'phui-hovercard' => '6199f752',
     'phui-hovercard-list' => 'de4b4919',
     'phui-hovercard-view-css' => '39fd2e14',
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2036,6 +2036,7 @@
     'PHUIBigInfoView' => 'view/phui/PHUIBigInfoView.php',
     'PHUIBoxExample' => 'applications/uiexample/examples/PHUIBoxExample.php',
     'PHUIBoxView' => 'view/phui/PHUIBoxView.php',
+    'PHUIBoxViewCollapsible' => 'view/phui/PHUIBoxViewCollapsible.php',
     'PHUIButtonBarExample' => 'applications/uiexample/examples/PHUIButtonBarExample.php',
     'PHUIButtonBarView' => 'view/phui/PHUIButtonBarView.php',
     'PHUIButtonExample' => 'applications/uiexample/examples/PHUIButtonExample.php',
@@ -2095,6 +2096,7 @@
     'PHUIHandleView' => 'applications/phid/view/PHUIHandleView.php',
     'PHUIHeadThingView' => 'view/phui/PHUIHeadThingView.php',
     'PHUIHeaderView' => 'view/phui/PHUIHeaderView.php',
+    'PHUIHeaderViewCollapsible' => 'view/phui/PHUIHeaderViewCollapsible.php',
     'PHUIHomeView' => 'applications/home/view/PHUIHomeView.php',
     'PHUIHovercardUIExample' => 'applications/uiexample/examples/PHUIHovercardUIExample.php',
     'PHUIHovercardView' => 'view/phui/PHUIHovercardView.php',
@@ -8289,6 +8291,7 @@
     'PHUIBigInfoView' => 'AphrontTagView',
     'PHUIBoxExample' => 'PhabricatorUIExample',
     'PHUIBoxView' => 'AphrontTagView',
+    'PHUIBoxViewCollapsible' => 'PHUIBoxView',
     'PHUIButtonBarExample' => 'PhabricatorUIExample',
     'PHUIButtonBarView' => 'AphrontTagView',
     'PHUIButtonExample' => 'PhabricatorUIExample',
@@ -8348,6 +8351,7 @@
     'PHUIHandleView' => 'AphrontView',
     'PHUIHeadThingView' => 'AphrontTagView',
     'PHUIHeaderView' => 'AphrontTagView',
+    'PHUIHeaderViewCollapsible' => 'PHUIHeaderView',
     'PHUIHomeView' => 'AphrontTagView',
     'PHUIHovercardUIExample' => 'PhabricatorUIExample',
     'PHUIHovercardView' => 'AphrontTagView',
diff --git a/src/view/phui/PHUIBoxView.php b/src/view/phui/PHUIBoxView.php
--- a/src/view/phui/PHUIBoxView.php
+++ b/src/view/phui/PHUIBoxView.php
@@ -1,6 +1,6 @@
 <?php
 
-final class PHUIBoxView extends AphrontTagView {
+class PHUIBoxView extends AphrontTagView {
 
   private $margin = array();
   private $padding = array();
diff --git a/src/view/phui/PHUIBoxViewCollapsible.php b/src/view/phui/PHUIBoxViewCollapsible.php
new file mode 100644
--- /dev/null
+++ b/src/view/phui/PHUIBoxViewCollapsible.php
@@ -0,0 +1,13 @@
+<?php
+
+final class PHUIBoxViewCollapsible extends PHUIBoxView {
+
+  protected function getTagName() {
+    return 'details';
+  }
+
+  protected function getTagAttributes() {
+    $attribute = array('open' => ''); // expand column by default
+    return array_merge(parent::getTagAttributes(), $attribute);
+  }
+}
diff --git a/src/view/phui/PHUIHeaderView.php b/src/view/phui/PHUIHeaderView.php
--- a/src/view/phui/PHUIHeaderView.php
+++ b/src/view/phui/PHUIHeaderView.php
@@ -1,6 +1,6 @@
 <?php
 
-final class PHUIHeaderView extends AphrontTagView {
+class PHUIHeaderView extends AphrontTagView {
 
   const PROPERTY_STATUS = 1;
 
diff --git a/src/view/phui/PHUIHeaderViewCollapsible.php b/src/view/phui/PHUIHeaderViewCollapsible.php
new file mode 100644
--- /dev/null
+++ b/src/view/phui/PHUIHeaderViewCollapsible.php
@@ -0,0 +1,9 @@
+<?php
+
+final class PHUIHeaderViewCollapsible extends PHUIHeaderView {
+
+  protected function getTagName() {
+    return 'summary';
+  }
+
+}
diff --git a/src/view/phui/PHUIWorkpanelView.php b/src/view/phui/PHUIWorkpanelView.php
--- a/src/view/phui/PHUIWorkpanelView.php
+++ b/src/view/phui/PHUIWorkpanelView.php
@@ -79,7 +79,7 @@
           $footer_tag);
     }
 
-    $header = id(new PHUIHeaderView())
+    $header = id(new PHUIHeaderViewCollapsible())
       ->setHeader($this->header)
       ->setSubheader($this->subheader);
 
@@ -109,7 +109,7 @@
 
     $body = phutil_tag_div('phui-workpanel-body', $body);
 
-    $view = id(new PHUIBoxView())
+    $view = id(new PHUIBoxViewCollapsible())
       ->setColor(PHUIBoxView::GREY)
       ->addClass('phui-workpanel-view-inner')
       ->appendChild(
diff --git a/webroot/rsrc/css/phui/phui-header-view.css b/webroot/rsrc/css/phui/phui-header-view.css
--- a/webroot/rsrc/css/phui/phui-header-view.css
+++ b/webroot/rsrc/css/phui/phui-header-view.css
@@ -56,6 +56,10 @@
   border-top-width: 0;
 }
 
+details > summary.phui-header-shell {
+  list-style: none;
+}
+
 .phui-property-list-view + .diviner-document-section {
   margin-top: -1px;
 }