diff --git a/src/DebugBar/DataFormatter/DebugBarVarDumper.php b/src/DebugBar/DataFormatter/DebugBarVarDumper.php
index 939c1a6..33cae38 100644
--- a/src/DebugBar/DataFormatter/DebugBarVarDumper.php
+++ b/src/DebugBar/DataFormatter/DebugBarVarDumper.php
@@ -3,13 +3,10 @@
 namespace DebugBar\DataFormatter;
 
 use DebugBar\DataCollector\AssetProvider;
-use Symfony\Component\VarDumper\Caster\Caster;
-use Symfony\Component\VarDumper\Cloner\Cursor;
+use DebugBar\DataFormatter\VarDumper\DebugBarHtmlDumper;
+use DebugBar\DataFormatter\VarDumper\SeekingData;
 use Symfony\Component\VarDumper\Cloner\Data;
-use Symfony\Component\VarDumper\Cloner\DumperInterface;
-use Symfony\Component\VarDumper\Cloner\Stub;
 use Symfony\Component\VarDumper\Cloner\VarCloner;
-use Symfony\Component\VarDumper\Dumper\HtmlDumper;
 
 /**
  * Clones and renders variables in HTML format using the Symfony VarDumper component.
@@ -48,7 +45,7 @@ class DebugBarVarDumper implements AssetProvider
     /** @var VarCloner */
     protected $cloner;
 
-    /** @var DebugBarHtmlDumper */
+    /** @var Debu */
     protected $dumper;
 
     /**
@@ -316,110 +313,3 @@ class DebugBarVarDumper implements AssetProvider
         return $result;
     }
 }
-
-/**
- * We have to extend the base HtmlDumper class in order to get access to the protected-only
- * getDumpHeader function.
- */
-class DebugBarHtmlDumper extends HtmlDumper
-{
-    public function getDumpHeaderByDebugBar() {
-        // getDumpHeader is protected:
-        return $this->getDumpHeader();
-    }
-}
-
-/**
- * This class backports the seek() function from Symfony 3.2 to older versions - up to v2.6.  The
- * class should not be used with newer Symfony versions that provide the seek function, as it relies
- * on a lot of undocumented functionality.
- */
-class SeekingData extends Data
-{
-    // Because the class copies/pastes the seek() implementation from Symfony 3.2, we reproduce its
-    // copyright here; this class is subject to the following additional copyright:
-
-    /*
-     * Copyright (c) 2014-2017 Fabien Potencier
-     *
-     * Permission is hereby granted, free of charge, to any person obtaining a copy
-     * of this software and associated documentation files (the "Software"), to deal
-     * in the Software without restriction, including without limitation the rights
-     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-     * copies of the Software, and to permit persons to whom the Software is furnished
-     * to do so, subject to the following conditions:
-     *
-     * The above copyright notice and this permission notice shall be included in all
-     * copies or substantial portions of the Software.
-     *
-     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-     * THE SOFTWARE.
-     */
-    private $position = 0;
-    private $key = 0;
-
-    /**
-     * Seeks to a specific key in nested data structures.
-     *
-     * @param string|int $key The key to seek to
-     *
-     * @return self|null A clone of $this of null if the key is not set
-     */
-    public function seek($key)
-    {
-        $thisData = $this->getRawData();
-        $item = $thisData[$this->position][$this->key];
-
-        if (!$item instanceof Stub || !$item->position) {
-            return;
-        }
-        $keys = array($key);
-
-        switch ($item->type) {
-            case Stub::TYPE_OBJECT:
-                $keys[] = "\0+\0".$key;
-                $keys[] = "\0*\0".$key;
-                $keys[] = "\0~\0".$key;
-                $keys[] = "\0$item->class\0$key";
-            case Stub::TYPE_ARRAY:
-            case Stub::TYPE_RESOURCE:
-                break;
-            default:
-                return;
-        }
-
-        $data = null;
-        $children = $thisData[$item->position];
-
-        foreach ($keys as $key) {
-            if (isset($children[$key]) || array_key_exists($key, $children)) {
-                $data = clone $this;
-                $data->key = $key;
-                $data->position = $item->position;
-                break;
-            }
-        }
-
-        return $data;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function dump(DumperInterface $dumper)
-    {
-        // Override the base class dump to use the position and key
-        $refs = array(0);
-        $class = new \ReflectionClass($this);
-        $dumpItem = $class->getMethod('dumpItem');
-        $dumpItem->setAccessible(true);
-        $data = $this->getRawData();
-        $args = array($dumper, new Cursor(), &$refs, $data[$this->position][$this->key]);
-        $dumpItem->invokeArgs($this, $args);
-    }
-}
diff --git a/src/DebugBar/DataFormatter/VarDumper/DebugbarHtmlDumper.php b/src/DebugBar/DataFormatter/VarDumper/DebugbarHtmlDumper.php
new file mode 100644
index 0000000..6026f3e
--- /dev/null
+++ b/src/DebugBar/DataFormatter/VarDumper/DebugbarHtmlDumper.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace DebugBar\DataFormatter\VarDumper;
+
+use Symfony\Component\VarDumper\Dumper\HtmlDumper;
+
+/**
+ * We have to extend the base HtmlDumper class in order to get access to the protected-only
+ * getDumpHeader function.
+ */
+class DebugBarHtmlDumper extends HtmlDumper
+{
+    public function getDumpHeaderByDebugBar() {
+        // getDumpHeader is protected:
+        return str_replace('pre.sf-dump', '.debugbar pre.sf-dump', $this->getDumpHeader());
+    }
+}
diff --git a/src/DebugBar/DataFormatter/VarDumper/SeekingData.php b/src/DebugBar/DataFormatter/VarDumper/SeekingData.php
new file mode 100644
index 0000000..be71ebf
--- /dev/null
+++ b/src/DebugBar/DataFormatter/VarDumper/SeekingData.php
@@ -0,0 +1,103 @@
+<?php
+
+namespace DebugBar\DataFormatter\VarDumper;
+
+use Symfony\Component\VarDumper\Cloner\Cursor;
+use Symfony\Component\VarDumper\Cloner\Data;
+use Symfony\Component\VarDumper\Cloner\DumperInterface;
+use Symfony\Component\VarDumper\Cloner\Stub;
+
+/**
+ * This class backports the seek() function from Symfony 3.2 to older versions - up to v2.6.  The
+ * class should not be used with newer Symfony versions that provide the seek function, as it relies
+ * on a lot of undocumented functionality.
+ */
+class SeekingData extends Data
+{
+    // Because the class copies/pastes the seek() implementation from Symfony 3.2, we reproduce its
+    // copyright here; this class is subject to the following additional copyright:
+
+    /*
+     * Copyright (c) 2014-2017 Fabien Potencier
+     *
+     * Permission is hereby granted, free of charge, to any person obtaining a copy
+     * of this software and associated documentation files (the "Software"), to deal
+     * in the Software without restriction, including without limitation the rights
+     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+     * copies of the Software, and to permit persons to whom the Software is furnished
+     * to do so, subject to the following conditions:
+     *
+     * The above copyright notice and this permission notice shall be included in all
+     * copies or substantial portions of the Software.
+     *
+     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+     * THE SOFTWARE.
+     */
+    private $position = 0;
+    private $key = 0;
+
+    /**
+     * Seeks to a specific key in nested data structures.
+     *
+     * @param string|int $key The key to seek to
+     *
+     * @return self|null A clone of $this of null if the key is not set
+     */
+    public function seek($key)
+    {
+        $thisData = $this->getRawData();
+        $item = $thisData[$this->position][$this->key];
+
+        if (!$item instanceof Stub || !$item->position) {
+            return;
+        }
+        $keys = array($key);
+
+        switch ($item->type) {
+            case Stub::TYPE_OBJECT:
+                $keys[] = "\0+\0".$key;
+                $keys[] = "\0*\0".$key;
+                $keys[] = "\0~\0".$key;
+                $keys[] = "\0$item->class\0$key";
+            case Stub::TYPE_ARRAY:
+            case Stub::TYPE_RESOURCE:
+                break;
+            default:
+                return;
+        }
+
+        $data = null;
+        $children = $thisData[$item->position];
+
+        foreach ($keys as $key) {
+            if (isset($children[$key]) || array_key_exists($key, $children)) {
+                $data = clone $this;
+                $data->key = $key;
+                $data->position = $item->position;
+                break;
+            }
+        }
+
+        return $data;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function dump(DumperInterface $dumper)
+    {
+        // Override the base class dump to use the position and key
+        $refs = array(0);
+        $class = new \ReflectionClass($this);
+        $dumpItem = $class->getMethod('dumpItem');
+        $dumpItem->setAccessible(true);
+        $data = $this->getRawData();
+        $args = array($dumper, new Cursor(), &$refs, $data[$this->position][$this->key]);
+        $dumpItem->invokeArgs($this, $args);
+    }
+}
diff --git a/src/DebugBar/Resources/debugbar.css b/src/DebugBar/Resources/debugbar.css
index e78a498..7f74444 100644
--- a/src/DebugBar/Resources/debugbar.css
+++ b/src/DebugBar/Resources/debugbar.css
@@ -89,6 +89,7 @@ div.phpdebugbar code, div.phpdebugbar pre {
 
 div.phpdebugbar pre.sf-dump {
   color: #a0a000;
+  outline: 0;
 }
 
 a.phpdebugbar-restore-btn {