diff --git a/lib/php-css-parser/CSSList/AtRuleBlockList.php b/lib/php-css-parser/CSSList/AtRuleBlockList.php
new file mode 100644
index 00000000000..a1ff8f8d10e
--- /dev/null
+++ b/lib/php-css-parser/CSSList/AtRuleBlockList.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace Sabberworm\CSS\CSSList;
+
+use Sabberworm\CSS\Property\AtRule;
+
+/**
+ * A BlockList constructed by an unknown @-rule. @media rules are rendered into AtRuleBlockList objects.
+ */
+class AtRuleBlockList extends CSSBlockList implements AtRule {
+
+	private $sType;
+	private $sArgs;
+
+	public function __construct($sType, $sArgs = '', $iLineNo = 0) {
+		parent::__construct($iLineNo);
+		$this->sType = $sType;
+		$this->sArgs = $sArgs;
+	}
+
+	public function atRuleName() {
+		return $this->sType;
+	}
+
+	public function atRuleArgs() {
+		return $this->sArgs;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sArgs = $this->sArgs;
+		if($sArgs) {
+			$sArgs = ' ' . $sArgs;
+		}
+		$sResult = "@{$this->sType}$sArgs{$oOutputFormat->spaceBeforeOpeningBrace()}{";
+		$sResult .= parent::render($oOutputFormat);
+		$sResult .= '}';
+		return $sResult;
+	}
+
+	public function isRootList() {
+		return false;
+	}
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/CSSList/CSSBlockList.php b/lib/php-css-parser/CSSList/CSSBlockList.php
new file mode 100644
index 00000000000..17c68142eb7
--- /dev/null
+++ b/lib/php-css-parser/CSSList/CSSBlockList.php
@@ -0,0 +1,82 @@
+<?php
+
+namespace Sabberworm\CSS\CSSList;
+
+use Sabberworm\CSS\RuleSet\DeclarationBlock;
+use Sabberworm\CSS\RuleSet\RuleSet;
+use Sabberworm\CSS\Property\Selector;
+use Sabberworm\CSS\Rule\Rule;
+use Sabberworm\CSS\Value\ValueList;
+use Sabberworm\CSS\Value\CSSFunction;
+
+/**
+ * A CSSBlockList is a CSSList whose DeclarationBlocks are guaranteed to contain valid declaration blocks or at-rules.
+ * Most CSSLists conform to this category but some at-rules (such as @keyframes) do not.
+ */
+abstract class CSSBlockList extends CSSList {
+	public function __construct($iLineNo = 0) {
+		parent::__construct($iLineNo);
+	}
+
+	protected function allDeclarationBlocks(&$aResult) {
+		foreach ($this->aContents as $mContent) {
+			if ($mContent instanceof DeclarationBlock) {
+				$aResult[] = $mContent;
+			} else if ($mContent instanceof CSSBlockList) {
+				$mContent->allDeclarationBlocks($aResult);
+			}
+		}
+	}
+
+	protected function allRuleSets(&$aResult) {
+		foreach ($this->aContents as $mContent) {
+			if ($mContent instanceof RuleSet) {
+				$aResult[] = $mContent;
+			} else if ($mContent instanceof CSSBlockList) {
+				$mContent->allRuleSets($aResult);
+			}
+		}
+	}
+
+	protected function allValues($oElement, &$aResult, $sSearchString = null, $bSearchInFunctionArguments = false) {
+		if ($oElement instanceof CSSBlockList) {
+			foreach ($oElement->getContents() as $oContent) {
+				$this->allValues($oContent, $aResult, $sSearchString, $bSearchInFunctionArguments);
+			}
+		} else if ($oElement instanceof RuleSet) {
+			foreach ($oElement->getRules($sSearchString) as $oRule) {
+				$this->allValues($oRule, $aResult, $sSearchString, $bSearchInFunctionArguments);
+			}
+		} else if ($oElement instanceof Rule) {
+			$this->allValues($oElement->getValue(), $aResult, $sSearchString, $bSearchInFunctionArguments);
+		} else if ($oElement instanceof ValueList) {
+			if ($bSearchInFunctionArguments || !($oElement instanceof CSSFunction)) {
+				foreach ($oElement->getListComponents() as $mComponent) {
+					$this->allValues($mComponent, $aResult, $sSearchString, $bSearchInFunctionArguments);
+				}
+			}
+		} else {
+			//Non-List Value or CSSString (CSS identifier)
+			$aResult[] = $oElement;
+		}
+	}
+
+	protected function allSelectors(&$aResult, $sSpecificitySearch = null) {
+		$aDeclarationBlocks = array();
+		$this->allDeclarationBlocks($aDeclarationBlocks);
+		foreach ($aDeclarationBlocks as $oBlock) {
+			foreach ($oBlock->getSelectors() as $oSelector) {
+				if ($sSpecificitySearch === null) {
+					$aResult[] = $oSelector;
+				} else {
+					$sComparison = "\$bRes = {$oSelector->getSpecificity()} $sSpecificitySearch;";
+					eval($sComparison);
+					if ($bRes) {
+						$aResult[] = $oSelector;
+					}
+				}
+			}
+		}
+	}
+
+}
diff --git a/lib/php-css-parser/CSSList/CSSList.php b/lib/php-css-parser/CSSList/CSSList.php
new file mode 100644
index 00000000000..bc90460b925
--- /dev/null
+++ b/lib/php-css-parser/CSSList/CSSList.php
@@ -0,0 +1,157 @@
+<?php
+
+namespace Sabberworm\CSS\CSSList;
+
+use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\RuleSet\DeclarationBlock;
+use Sabberworm\CSS\RuleSet\RuleSet;
+use Sabberworm\CSS\Property\Selector;
+use Sabberworm\CSS\Comment\Commentable;
+
+/**
+ * A CSSList is the most generic container available. Its contents include RuleSet as well as other CSSList objects.
+ * Also, it may contain Import and Charset objects stemming from @-rules.
+ */
+abstract class CSSList implements Renderable, Commentable {
+
+	protected $aComments;
+	protected $aContents;
+	protected $iLineNo;
+
+	public function __construct($iLineNo = 0) {
+		$this->aComments = array();
+		$this->aContents = array();
+		$this->iLineNo = $iLineNo;
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	public function append($oItem) {
+		$this->aContents[] = $oItem;
+	}
+
+	/**
+	 * Removes an item from the CSS list.
+	 * @param RuleSet|Import|Charset|CSSList $oItemToRemove May be a RuleSet (most likely a DeclarationBlock), a Import, a Charset or another CSSList (most likely a MediaQuery)
+	 */
+	public function remove($oItemToRemove) {
+		$iKey = array_search($oItemToRemove, $this->aContents, true);
+		if ($iKey !== false) {
+			unset($this->aContents[$iKey]);
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Set the contents.
+	 * @param array $aContents Objects to set as content.
+	 */
+	public function setContents(array $aContents) {
+		$this->aContents = array();
+		foreach ($aContents as $content) {
+			$this->append($content);
+		}
+	}
+
+	/**
+	 * Removes a declaration block from the CSS list if it matches all given selectors.
+	 * @param array|string $mSelector The selectors to match.
+	 * @param boolean $bRemoveAll Whether to stop at the first declaration block found or remove all blocks
+	 */
+	public function removeDeclarationBlockBySelector($mSelector, $bRemoveAll = false) {
+		if ($mSelector instanceof DeclarationBlock) {
+			$mSelector = $mSelector->getSelectors();
+		}
+		if (!is_array($mSelector)) {
+			$mSelector = explode(',', $mSelector);
+		}
+		foreach ($mSelector as $iKey => &$mSel) {
+			if (!($mSel instanceof Selector)) {
+				$mSel = new Selector($mSel);
+			}
+		}
+		foreach ($this->aContents as $iKey => $mItem) {
+			if (!($mItem instanceof DeclarationBlock)) {
+				continue;
+			}
+			if ($mItem->getSelectors() == $mSelector) {
+				unset($this->aContents[$iKey]);
+				if (!$bRemoveAll) {
+					return;
+				}
+			}
+		}
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sResult = '';
+		$bIsFirst = true;
+		$oNextLevel = $oOutputFormat;
+		if(!$this->isRootList()) {
+			$oNextLevel = $oOutputFormat->nextLevel();
+		}
+		foreach ($this->aContents as $oContent) {
+			$sRendered = $oOutputFormat->safely(function() use ($oNextLevel, $oContent) {
+				return $oContent->render($oNextLevel);
+			});
+			if($sRendered === null) {
+				continue;
+			}
+			if($bIsFirst) {
+				$bIsFirst = false;
+				$sResult .= $oNextLevel->spaceBeforeBlocks();
+			} else {
+				$sResult .= $oNextLevel->spaceBetweenBlocks();
+			}
+			$sResult .= $sRendered;
+		}
+
+		if(!$bIsFirst) {
+			// Had some output
+			$sResult .= $oOutputFormat->spaceAfterBlocks();
+		}
+
+		return $sResult;
+	}
+	
+	/**
+	* Return true if the list can not be further outdented. Only important when rendering.
+	*/
+	public abstract function isRootList();
+
+	public function getContents() {
+		return $this->aContents;
+	}
+
+	/**
+	 * @param array $aComments Array of comments.
+	 */
+	public function addComments(array $aComments) {
+		$this->aComments = array_merge($this->aComments, $aComments);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getComments() {
+		return $this->aComments;
+	}
+
+	/**
+	 * @param array $aComments Array containing Comment objects.
+	 */
+	public function setComments(array $aComments) {
+		$this->aComments = $aComments;
+	}
+
+}
diff --git a/lib/php-css-parser/CSSList/Document.php b/lib/php-css-parser/CSSList/Document.php
new file mode 100644
index 00000000000..bd4a23ee319
--- /dev/null
+++ b/lib/php-css-parser/CSSList/Document.php
@@ -0,0 +1,105 @@
+<?php
+
+namespace Sabberworm\CSS\CSSList;
+
+/**
+ * The root CSSList of a parsed file. Contains all top-level css contents, mostly declaration blocks, but also any @-rules encountered.
+ */
+class Document extends CSSBlockList {
+	/**
+	 * Document constructor.
+	 * @param int $iLineNo
+	 */
+	public function __construct($iLineNo = 0) {
+		parent::__construct($iLineNo);
+	}
+
+	/**
+	 * Gets all DeclarationBlock objects recursively.
+	 */
+	public function getAllDeclarationBlocks() {
+		$aResult = array();
+		$this->allDeclarationBlocks($aResult);
+		return $aResult;
+	}
+
+	/**
+	 * @deprecated use getAllDeclarationBlocks()
+	 */
+	public function getAllSelectors() {
+		return $this->getAllDeclarationBlocks();
+	}
+
+	/**
+	 * Returns all RuleSet objects found recursively in the tree.
+	 */
+	public function getAllRuleSets() {
+		$aResult = array();
+		$this->allRuleSets($aResult);
+		return $aResult;
+	}
+
+	/**
+	 * Returns all Value objects found recursively in the tree.
+	 * @param (object|string) $mElement the CSSList or RuleSet to start the search from (defaults to the whole document). If a string is given, it is used as rule name filter (@see{RuleSet->getRules()}).
+	 * @param (bool) $bSearchInFunctionArguments whether to also return Value objects used as Function arguments.
+	 */
+	public function getAllValues($mElement = null, $bSearchInFunctionArguments = false) {
+		$sSearchString = null;
+		if ($mElement === null) {
+			$mElement = $this;
+		} else if (is_string($mElement)) {
+			$sSearchString = $mElement;
+			$mElement = $this;
+		}
+		$aResult = array();
+		$this->allValues($mElement, $aResult, $sSearchString, $bSearchInFunctionArguments);
+		return $aResult;
+	}
+
+	/**
+	 * Returns all Selector objects found recursively in the tree.
+	 * Note that this does not yield the full DeclarationBlock that the selector belongs to (and, currently, there is no way to get to that).
+	 * @param $sSpecificitySearch An optional filter by specificity. May contain a comparison operator and a number or just a number (defaults to "==").
+	 * @example getSelectorsBySpecificity('>= 100')
+	 */
+	public function getSelectorsBySpecificity($sSpecificitySearch = null) {
+		if (is_numeric($sSpecificitySearch) || is_numeric($sSpecificitySearch[0])) {
+			$sSpecificitySearch = "== $sSpecificitySearch";
+		}
+		$aResult = array();
+		$this->allSelectors($aResult, $sSpecificitySearch);
+		return $aResult;
+	}
+
+	/**
+	 * Expands all shorthand properties to their long value
+	 */
+	public function expandShorthands() {
+		foreach ($this->getAllDeclarationBlocks() as $oDeclaration) {
+			$oDeclaration->expandShorthands();
+		}
+	}
+
+	/**
+	 * Create shorthands properties whenever possible
+	 */
+	public function createShorthands() {
+		foreach ($this->getAllDeclarationBlocks() as $oDeclaration) {
+			$oDeclaration->createShorthands();
+		}
+	}
+
+	// Override render() to make format argument optional
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat = null) {
+		if($oOutputFormat === null) {
+			$oOutputFormat = new \Sabberworm\CSS\OutputFormat();
+		}
+		return parent::render($oOutputFormat);
+	}
+
+	public function isRootList() {
+		return true;
+	}
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/CSSList/KeyFrame.php b/lib/php-css-parser/CSSList/KeyFrame.php
new file mode 100644
index 00000000000..0334b1b3f18
--- /dev/null
+++ b/lib/php-css-parser/CSSList/KeyFrame.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Sabberworm\CSS\CSSList;
+
+use Sabberworm\CSS\Property\AtRule;
+
+class KeyFrame extends CSSList implements AtRule {
+
+	private $vendorKeyFrame;
+	private $animationName;
+
+	public function __construct($iLineNo = 0) {
+		parent::__construct($iLineNo);
+		$this->vendorKeyFrame = null;
+		$this->animationName  = null;
+	}
+
+	public function setVendorKeyFrame($vendorKeyFrame) {
+		$this->vendorKeyFrame = $vendorKeyFrame;
+	}
+
+	public function getVendorKeyFrame() {
+		return $this->vendorKeyFrame;
+	}
+
+	public function setAnimationName($animationName) {
+		$this->animationName = $animationName;
+	}
+
+	public function getAnimationName() {
+		return $this->animationName;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sResult = "@{$this->vendorKeyFrame} {$this->animationName}{$oOutputFormat->spaceBeforeOpeningBrace()}{";
+		$sResult .= parent::render($oOutputFormat);
+		$sResult .= '}';
+		return $sResult;
+	}
+
+	public function isRootList() {
+		return false;
+	}
+
+	public function atRuleName() {
+		return $this->vendorKeyFrame;
+	}
+
+	public function atRuleArgs() {
+		return $this->animationName;
+	}
+}
diff --git a/lib/php-css-parser/Comment/Comment.php b/lib/php-css-parser/Comment/Comment.php
new file mode 100644
index 00000000000..70521b16a3d
--- /dev/null
+++ b/lib/php-css-parser/Comment/Comment.php
@@ -0,0 +1,51 @@
+<?php
+
+namespace Sabberworm\CSS\Comment;
+
+use Sabberworm\CSS\Renderable;
+
+class Comment implements Renderable {
+	protected $iLineNo;
+	protected $sComment;
+
+	public function __construct($sComment = '', $iLineNo = 0) {
+		$this->sComment = $sComment;
+		$this->iLineNo = $iLineNo;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getComment() {
+		return $this->sComment;
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function setComment($sComment) {
+		$this->sComment = $sComment;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	/**
+	 * @return string
+	 */
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		return '/*' . $this->sComment . '*/';
+	}
+
+}
diff --git a/lib/php-css-parser/Comment/Commentable.php b/lib/php-css-parser/Comment/Commentable.php
new file mode 100644
index 00000000000..3100f17a8fa
--- /dev/null
+++ b/lib/php-css-parser/Comment/Commentable.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Sabberworm\CSS\Comment;
+
+interface Commentable {
+
+	/**
+	 * @param array $aComments Array of comments.
+	 */
+	public function addComments(array $aComments);
+
+	/**
+	 * @return array
+	 */
+	public function getComments();
+
+	/**
+	 * @param array $aComments Array containing Comment objects.
+	 */
+	public function setComments(array $aComments);
+
+
+}
diff --git a/lib/php-css-parser/OutputFormat.php b/lib/php-css-parser/OutputFormat.php
new file mode 100644
index 00000000000..1b179840268
--- /dev/null
+++ b/lib/php-css-parser/OutputFormat.php
@@ -0,0 +1,289 @@
+<?php
+
+namespace Sabberworm\CSS;
+
+use Sabberworm\CSS\Parsing\OutputException;
+
+class OutputFormat {
+	/**
+	* Value format
+	*/
+	// " means double-quote, ' means single-quote
+	public $sStringQuotingType = '"';
+	// Output RGB colors in hash notation if possible
+	public $bRGBHashNotation = true;
+	
+	/**
+	* Declaration format
+	*/
+	// Semicolon after the last rule of a declaration block can be omitted. To do that, set this false.
+	public $bSemicolonAfterLastRule = true;
+	
+	/**
+	* Spacing
+	* Note that these strings are not sanity-checked: the value should only consist of whitespace
+	* Any newline character will be indented according to the current level.
+	* The triples (After, Before, Between) can be set using a wildcard (e.g. `$oFormat->set('Space*Rules', "\n");`)
+	*/
+	public $sSpaceAfterRuleName = ' ';
+
+	public $sSpaceBeforeRules = '';
+	public $sSpaceAfterRules = '';
+	public $sSpaceBetweenRules = '';
+
+	public $sSpaceBeforeBlocks = '';
+	public $sSpaceAfterBlocks = '';
+	public $sSpaceBetweenBlocks = "\n";
+
+	// This is what’s printed before and after the comma if a declaration block contains multiple selectors.
+	public $sSpaceBeforeSelectorSeparator = '';
+	public $sSpaceAfterSelectorSeparator = ' ';
+	// This is what’s printed after the comma of value lists
+	public $sSpaceBeforeListArgumentSeparator = '';
+	public $sSpaceAfterListArgumentSeparator = '';
+	
+	public $sSpaceBeforeOpeningBrace = ' ';
+	
+	/**
+	* Indentation
+	*/
+	// Indentation character(s) per level. Only applicable if newlines are used in any of the spacing settings.
+	public $sIndentation = "\t";
+	
+	/**
+	* Output exceptions.
+	*/
+	public $bIgnoreExceptions = false;
+	
+	
+	private $oFormatter = null;
+	private $oNextLevelFormat = null;
+	private $iIndentationLevel = 0;
+	
+	public function __construct() {
+	}
+	
+	public function get($sName) {
+		$aVarPrefixes = array('a', 's', 'm', 'b', 'f', 'o', 'c', 'i');
+		foreach($aVarPrefixes as $sPrefix) {
+			$sFieldName = $sPrefix.ucfirst($sName);
+			if(isset($this->$sFieldName)) {
+				return $this->$sFieldName;
+			}
+		}
+		return null;
+	}
+	
+	public function set($aNames, $mValue) {
+		$aVarPrefixes = array('a', 's', 'm', 'b', 'f', 'o', 'c', 'i');
+		if(is_string($aNames) && strpos($aNames, '*') !== false) {
+			$aNames = array(str_replace('*', 'Before', $aNames), str_replace('*', 'Between', $aNames), str_replace('*', 'After', $aNames));
+		} else if(!is_array($aNames)) {
+			$aNames = array($aNames);
+		}
+		foreach($aVarPrefixes as $sPrefix) {
+			$bDidReplace = false;
+			foreach($aNames as $sName) {
+				$sFieldName = $sPrefix.ucfirst($sName);
+				if(isset($this->$sFieldName)) {
+					$this->$sFieldName = $mValue;
+					$bDidReplace = true;
+				}
+			}
+			if($bDidReplace) {
+				return $this;
+			}
+		}
+		// Break the chain so the user knows this option is invalid
+		return false;
+	}
+	
+	public function __call($sMethodName, $aArguments) {
+		if(strpos($sMethodName, 'set') === 0) {
+			return $this->set(substr($sMethodName, 3), $aArguments[0]);
+		} else if(strpos($sMethodName, 'get') === 0) {
+			return $this->get(substr($sMethodName, 3));
+		} else if(method_exists('\\Sabberworm\\CSS\\OutputFormatter', $sMethodName)) {
+			return call_user_func_array(array($this->getFormatter(), $sMethodName), $aArguments);
+		} else {
+			throw new \Exception('Unknown OutputFormat method called: '.$sMethodName);
+		}
+	}
+	
+	public function indentWithTabs($iNumber = 1) {
+		return $this->setIndentation(str_repeat("\t", $iNumber));
+	}
+	
+	public function indentWithSpaces($iNumber = 2) {
+		return $this->setIndentation(str_repeat(" ", $iNumber));
+	}
+	
+	public function nextLevel() {
+		if($this->oNextLevelFormat === null) {
+			$this->oNextLevelFormat = clone $this;
+			$this->oNextLevelFormat->iIndentationLevel++;
+			$this->oNextLevelFormat->oFormatter = null;
+		}
+		return $this->oNextLevelFormat;
+	}
+	
+	public function beLenient() {
+		$this->bIgnoreExceptions = true;
+	}
+	
+	public function getFormatter() {
+		if($this->oFormatter === null) {
+			$this->oFormatter = new OutputFormatter($this);
+		}
+		return $this->oFormatter;
+	}
+	
+	public function level() {
+		return $this->iIndentationLevel;
+	}
+	
+	public static function create() {
+		return new OutputFormat();
+	}
+	
+	public static function createCompact() {
+		return self::create()->set('Space*Rules', "")->set('Space*Blocks', "")->setSpaceAfterRuleName('')->setSpaceBeforeOpeningBrace('')->setSpaceAfterSelectorSeparator('');
+	}
+	
+	public static function createPretty() {
+		return self::create()->set('Space*Rules', "\n")->set('Space*Blocks', "\n")->setSpaceBetweenBlocks("\n\n")->set('SpaceAfterListArgumentSeparator', array('default' => '', ',' => ' '));
+	}
+}
+
+class OutputFormatter {
+	private $oFormat;
+	
+	public function __construct(OutputFormat $oFormat) {
+		$this->oFormat = $oFormat;
+	}
+	
+	public function space($sName, $sType = null) {
+		$sSpaceString = $this->oFormat->get("Space$sName");
+		// If $sSpaceString is an array, we have multple values configured depending on the type of object the space applies to
+		if(is_array($sSpaceString)) {
+			if($sType !== null && isset($sSpaceString[$sType])) {
+				$sSpaceString = $sSpaceString[$sType];
+			} else {
+				$sSpaceString = reset($sSpaceString);
+			}
+		}
+		return $this->prepareSpace($sSpaceString);
+	}
+	
+	public function spaceAfterRuleName() {
+		return $this->space('AfterRuleName');
+	}
+	
+	public function spaceBeforeRules() {
+		return $this->space('BeforeRules');
+	}
+	
+	public function spaceAfterRules() {
+		return $this->space('AfterRules');
+	}
+	
+	public function spaceBetweenRules() {
+		return $this->space('BetweenRules');
+	}
+	
+	public function spaceBeforeBlocks() {
+		return $this->space('BeforeBlocks');
+	}
+	
+	public function spaceAfterBlocks() {
+		return $this->space('AfterBlocks');
+	}
+	
+	public function spaceBetweenBlocks() {
+		return $this->space('BetweenBlocks');
+	}
+	
+	public function spaceBeforeSelectorSeparator() {
+		return $this->space('BeforeSelectorSeparator');
+	}
+
+	public function spaceAfterSelectorSeparator() {
+		return $this->space('AfterSelectorSeparator');
+	}
+
+	public function spaceBeforeListArgumentSeparator($sSeparator) {
+		return $this->space('BeforeListArgumentSeparator', $sSeparator);
+	}
+
+	public function spaceAfterListArgumentSeparator($sSeparator) {
+		return $this->space('AfterListArgumentSeparator', $sSeparator);
+	}
+
+	public function spaceBeforeOpeningBrace() {
+		return $this->space('BeforeOpeningBrace');
+	}
+
+	/**
+	* Runs the given code, either swallowing or passing exceptions, depending on the bIgnoreExceptions setting.
+	*/
+	public function safely($cCode) {
+		if($this->oFormat->get('IgnoreExceptions')) {
+			// If output exceptions are ignored, run the code with exception guards
+			try {
+				return $cCode();
+			} catch (OutputException $e) {
+				return null;
+			} //Do nothing
+		} else {
+			// Run the code as-is
+			return $cCode();
+		}
+	}
+
+	/**
+	* Clone of the implode function but calls ->render with the current output format instead of __toString()
+	*/
+	public function implode($sSeparator, $aValues, $bIncreaseLevel = false) {
+		$sResult = '';
+		$oFormat = $this->oFormat;
+		if($bIncreaseLevel) {
+			$oFormat = $oFormat->nextLevel();
+		}
+		$bIsFirst = true;
+		foreach($aValues as $mValue) {
+			if($bIsFirst) {
+				$bIsFirst = false;
+			} else {
+				$sResult .= $sSeparator;
+			}
+			if($mValue instanceof \Sabberworm\CSS\Renderable) {
+				$sResult .= $mValue->render($oFormat);
+			} else {
+				$sResult .= $mValue;
+			}
+		}
+		return $sResult;
+	}
+	
+	public function removeLastSemicolon($sString) {
+		if($this->oFormat->get('SemicolonAfterLastRule')) {
+			return $sString;
+		}
+		$sString = explode(';', $sString);
+		if(count($sString) < 2) {
+			return $sString[0];
+		}
+		$sLast = array_pop($sString);
+		$sNextToLast = array_pop($sString);
+		array_push($sString, $sNextToLast.$sLast);
+		return implode(';', $sString);
+	}
+
+	private function prepareSpace($sSpaceString) {
+		return str_replace("\n", "\n".$this->indent(), $sSpaceString);
+	}
+
+	private function indent() {
+		return str_repeat($this->oFormat->sIndentation, $this->oFormat->level());
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Parser.php b/lib/php-css-parser/Parser.php
new file mode 100644
index 00000000000..409b796d618
--- /dev/null
+++ b/lib/php-css-parser/Parser.php
@@ -0,0 +1,727 @@
+<?php
+
+namespace Sabberworm\CSS;
+
+use Sabberworm\CSS\CSSList\CSSList;
+use Sabberworm\CSS\CSSList\Document;
+use Sabberworm\CSS\CSSList\KeyFrame;
+use Sabberworm\CSS\Parsing\SourceException;
+use Sabberworm\CSS\Property\AtRule;
+use Sabberworm\CSS\Property\Import;
+use Sabberworm\CSS\Property\Charset;
+use Sabberworm\CSS\Property\CSSNamespace;
+use Sabberworm\CSS\RuleSet\AtRuleSet;
+use Sabberworm\CSS\CSSList\AtRuleBlockList;
+use Sabberworm\CSS\RuleSet\DeclarationBlock;
+use Sabberworm\CSS\Value\CSSFunction;
+use Sabberworm\CSS\Value\RuleValueList;
+use Sabberworm\CSS\Value\Size;
+use Sabberworm\CSS\Value\Color;
+use Sabberworm\CSS\Value\URL;
+use Sabberworm\CSS\Value\CSSString;
+use Sabberworm\CSS\Rule\Rule;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Comment\Comment;
+
+/**
+ * Parser class parses CSS from text into a data structure.
+ */
+class Parser {
+
+	private $sText;
+	private $aText;
+	private $iCurrentPosition;
+	private $oParserSettings;
+	private $sCharset;
+	private $iLength;
+	private $blockRules;
+	private $aSizeUnits;
+	private $iLineNo;
+
+	/**
+	 * Parser constructor.
+	 * Note that that iLineNo starts from 1 and not 0
+	 *
+	 * @param $sText
+	 * @param Settings|null $oParserSettings
+	 * @param int $iLineNo
+	 */
+	public function __construct($sText, Settings $oParserSettings = null, $iLineNo = 1) {
+		$this->sText = $sText;
+		$this->iCurrentPosition = 0;
+		$this->iLineNo = $iLineNo;
+		if ($oParserSettings === null) {
+			$oParserSettings = Settings::create();
+		}
+		$this->oParserSettings = $oParserSettings;
+		$this->blockRules = explode('/', AtRule::BLOCK_RULES);
+
+		foreach (explode('/', Size::ABSOLUTE_SIZE_UNITS.'/'.Size::RELATIVE_SIZE_UNITS.'/'.Size::NON_SIZE_UNITS) as $val) {
+			$iSize = strlen($val);
+			if(!isset($this->aSizeUnits[$iSize])) {
+				$this->aSizeUnits[$iSize] = array();
+			}
+			$this->aSizeUnits[$iSize][strtolower($val)] = $val;
+		}
+		ksort($this->aSizeUnits, SORT_NUMERIC);
+	}
+
+	public function setCharset($sCharset) {
+		$this->sCharset = $sCharset;
+		$this->aText = $this->strsplit($this->sText);
+		$this->iLength = count($this->aText);
+	}
+
+	public function getCharset() {
+		return $this->sCharset;
+	}
+
+	public function parse() {
+		$this->setCharset($this->oParserSettings->sDefaultCharset);
+		$oResult = new Document($this->iLineNo);
+		$this->parseDocument($oResult);
+		return $oResult;
+	}
+
+	private function parseDocument(Document $oDocument) {
+		$this->parseList($oDocument, true);
+	}
+
+	private function parseList(CSSList $oList, $bIsRoot = false) {
+		while (!$this->isEnd()) {
+			$comments = $this->consumeWhiteSpace();
+			$oListItem = null;
+			if($this->oParserSettings->bLenientParsing) {
+				try {
+					$oListItem = $this->parseListItem($oList, $bIsRoot);
+				} catch (UnexpectedTokenException $e) {
+					$oListItem = false;
+				}
+			} else {
+				$oListItem = $this->parseListItem($oList, $bIsRoot);
+			}
+			if($oListItem === null) {
+				// List parsing finished
+				return;
+			}
+			if($oListItem) {
+				$oListItem->setComments($comments);
+				$oList->append($oListItem);
+			}
+		}
+		if (!$bIsRoot) {
+			throw new SourceException("Unexpected end of document", $this->iLineNo);
+		}
+	}
+	
+	private function parseListItem(CSSList $oList, $bIsRoot = false) {
+		if ($this->comes('@')) {
+			$oAtRule = $this->parseAtRule();
+			if($oAtRule instanceof Charset) {
+				if(!$bIsRoot) {
+					throw new UnexpectedTokenException('@charset may only occur in root document', '', 'custom', $this->iLineNo);
+				}
+				if(count($oList->getContents()) > 0) {
+					throw new UnexpectedTokenException('@charset must be the first parseable token in a document', '', 'custom', $this->iLineNo);
+				}
+				$this->setCharset($oAtRule->getCharset()->getString());
+			}
+			return $oAtRule;
+		} else if ($this->comes('}')) {
+			$this->consume('}');
+			if ($bIsRoot) {
+				throw new SourceException("Unopened {", $this->iLineNo);
+			} else {
+				return null;
+			}
+		} else {
+			return $this->parseSelector();
+		}
+	}
+
+	private function parseAtRule() {
+		$this->consume('@');
+		$sIdentifier = $this->parseIdentifier(false);
+		$iIdentifierLineNum = $this->iLineNo;
+		$this->consumeWhiteSpace();
+		if ($sIdentifier === 'import') {
+			$oLocation = $this->parseURLValue();
+			$this->consumeWhiteSpace();
+			$sMediaQuery = null;
+			if (!$this->comes(';')) {
+				$sMediaQuery = $this->consumeUntil(';');
+			}
+			$this->consume(';');
+			return new Import($oLocation, $sMediaQuery, $iIdentifierLineNum);
+		} else if ($sIdentifier === 'charset') {
+			$sCharset = $this->parseStringValue();
+			$this->consumeWhiteSpace();
+			$this->consume(';');
+			return new Charset($sCharset, $iIdentifierLineNum);
+		} else if ($this->identifierIs($sIdentifier, 'keyframes')) {
+			$oResult = new KeyFrame($iIdentifierLineNum);
+			$oResult->setVendorKeyFrame($sIdentifier);
+			$oResult->setAnimationName(trim($this->consumeUntil('{', false, true)));
+			$this->parseList($oResult);
+			return $oResult;
+		} else if ($sIdentifier === 'namespace') {
+			$sPrefix = null;
+			$mUrl = $this->parsePrimitiveValue();
+			if (!$this->comes(';')) {
+				$sPrefix = $mUrl;
+				$mUrl = $this->parsePrimitiveValue();
+			}
+			$this->consume(';');
+			if ($sPrefix !== null && !is_string($sPrefix)) {
+				throw new UnexpectedTokenException('Wrong namespace prefix', $sPrefix, 'custom', $iIdentifierLineNum);
+			}
+			if (!($mUrl instanceof CSSString || $mUrl instanceof URL)) {
+				throw new UnexpectedTokenException('Wrong namespace url of invalid type', $mUrl, 'custom', $iIdentifierLineNum);
+			}
+			return new CSSNamespace($mUrl, $sPrefix, $iIdentifierLineNum);
+		} else {
+			//Unknown other at rule (font-face or such)
+			$sArgs = trim($this->consumeUntil('{', false, true));
+			$bUseRuleSet = true;
+			foreach($this->blockRules as $sBlockRuleName) {
+				if($this->identifierIs($sIdentifier, $sBlockRuleName)) {
+					$bUseRuleSet = false;
+					break;
+				}
+			}
+			if($bUseRuleSet) {
+				$oAtRule = new AtRuleSet($sIdentifier, $sArgs, $iIdentifierLineNum);
+				$this->parseRuleSet($oAtRule);
+			} else {
+				$oAtRule = new AtRuleBlockList($sIdentifier, $sArgs, $iIdentifierLineNum);
+				$this->parseList($oAtRule);
+			}
+			return $oAtRule;
+		}
+	}
+
+	private function parseIdentifier($bAllowFunctions = true, $bIgnoreCase = true) {
+		$sResult = $this->parseCharacter(true);
+		if ($sResult === null) {
+			throw new UnexpectedTokenException($sResult, $this->peek(5), 'identifier', $this->iLineNo);
+		}
+		$sCharacter = null;
+		while (($sCharacter = $this->parseCharacter(true)) !== null) {
+			$sResult .= $sCharacter;
+		}
+		if ($bIgnoreCase) {
+			$sResult = $this->strtolower($sResult);
+		}
+		if ($bAllowFunctions && $this->comes('(')) {
+			$this->consume('(');
+			$aArguments = $this->parseValue(array('=', ' ', ','));
+			$sResult = new CSSFunction($sResult, $aArguments, ',', $this->iLineNo);
+			$this->consume(')');
+		}
+		return $sResult;
+	}
+
+	private function parseStringValue() {
+		$sBegin = $this->peek();
+		$sQuote = null;
+		if ($sBegin === "'") {
+			$sQuote = "'";
+		} else if ($sBegin === '"') {
+			$sQuote = '"';
+		}
+		if ($sQuote !== null) {
+			$this->consume($sQuote);
+		}
+		$sResult = "";
+		$sContent = null;
+		if ($sQuote === null) {
+			//Unquoted strings end in whitespace or with braces, brackets, parentheses
+			while (!preg_match('/[\\s{}()<>\\[\\]]/isu', $this->peek())) {
+				$sResult .= $this->parseCharacter(false);
+			}
+		} else {
+			while (!$this->comes($sQuote)) {
+				$sContent = $this->parseCharacter(false);
+				if ($sContent === null) {
+					throw new SourceException("Non-well-formed quoted string {$this->peek(3)}", $this->iLineNo);
+				}
+				$sResult .= $sContent;
+			}
+			$this->consume($sQuote);
+		}
+		return new CSSString($sResult, $this->iLineNo);
+	}
+
+	private function parseCharacter($bIsForIdentifier) {
+		if ($this->peek() === '\\') {
+			if ($bIsForIdentifier && $this->oParserSettings->bLenientParsing && ($this->comes('\0') || $this->comes('\9'))) {
+				// Non-strings can contain \0 or \9 which is an IE hack supported in lenient parsing.
+				return null;
+			}
+			$this->consume('\\');
+			if ($this->comes('\n') || $this->comes('\r')) {
+				return '';
+			}
+			if (preg_match('/[0-9a-fA-F]/Su', $this->peek()) === 0) {
+				return $this->consume(1);
+			}
+			$sUnicode = $this->consumeExpression('/^[0-9a-fA-F]{1,6}/u');
+			if ($this->strlen($sUnicode) < 6) {
+				//Consume whitespace after incomplete unicode escape
+				if (preg_match('/\\s/isSu', $this->peek())) {
+					if ($this->comes('\r\n')) {
+						$this->consume(2);
+					} else {
+						$this->consume(1);
+					}
+				}
+			}
+			$iUnicode = intval($sUnicode, 16);
+			$sUtf32 = "";
+			for ($i = 0; $i < 4; ++$i) {
+				$sUtf32 .= chr($iUnicode & 0xff);
+				$iUnicode = $iUnicode >> 8;
+			}
+			return iconv('utf-32le', $this->sCharset, $sUtf32);
+		}
+		if ($bIsForIdentifier) {
+			$peek = ord($this->peek());
+			// Ranges: a-z A-Z 0-9 - _
+			if (($peek >= 97 && $peek <= 122) ||
+				($peek >= 65 && $peek <= 90) ||
+				($peek >= 48 && $peek <= 57) ||
+				($peek === 45) ||
+				($peek === 95) ||
+				($peek > 0xa1)) {
+				return $this->consume(1);
+			}
+		} else {
+			return $this->consume(1);
+		}
+		return null;
+	}
+
+	private function parseSelector() {
+		$aComments = array();
+		$oResult = new DeclarationBlock($this->iLineNo);
+		$oResult->setSelector($this->consumeUntil('{', false, true, $aComments));
+		$oResult->setComments($aComments);
+		$this->parseRuleSet($oResult);
+		return $oResult;
+	}
+
+	private function parseRuleSet($oRuleSet) {
+		while ($this->comes(';')) {
+			$this->consume(';');
+		}
+		while (!$this->comes('}')) {
+			$oRule = null;
+			if($this->oParserSettings->bLenientParsing) {
+				try {
+					$oRule = $this->parseRule();
+				} catch (UnexpectedTokenException $e) {
+					try {
+						$sConsume = $this->consumeUntil(array("\n", ";", '}'), true);
+						// We need to “unfind” the matches to the end of the ruleSet as this will be matched later
+						if($this->streql(substr($sConsume, -1), '}')) {
+							--$this->iCurrentPosition;
+						} else {
+							while ($this->comes(';')) {
+								$this->consume(';');
+							}
+						}
+					} catch (UnexpectedTokenException $e) {
+						// We’ve reached the end of the document. Just close the RuleSet.
+						return;
+					}
+				}
+			} else {
+				$oRule = $this->parseRule();
+			}
+			if($oRule) {
+				$oRuleSet->addRule($oRule);
+			}
+		}
+		$this->consume('}');
+	}
+
+	private function parseRule() {
+		$aComments = $this->consumeWhiteSpace();
+		$oRule = new Rule($this->parseIdentifier(), $this->iLineNo);
+		$oRule->setComments($aComments);
+		$oRule->addComments($this->consumeWhiteSpace());
+		$this->consume(':');
+		$oValue = $this->parseValue(self::listDelimiterForRule($oRule->getRule()));
+		$oRule->setValue($oValue);
+		if ($this->oParserSettings->bLenientParsing) {
+			while ($this->comes('\\')) {
+				$this->consume('\\');
+				$oRule->addIeHack($this->consume());
+				$this->consumeWhiteSpace();
+			}
+		}
+		if ($this->comes('!')) {
+			$this->consume('!');
+			$this->consumeWhiteSpace();
+			$this->consume('important');
+			$oRule->setIsImportant(true);
+		}
+		while ($this->comes(';')) {
+			$this->consume(';');
+		}
+		return $oRule;
+	}
+
+	private function parseValue($aListDelimiters) {
+		$aStack = array();
+		$this->consumeWhiteSpace();
+		//Build a list of delimiters and parsed values
+		while (!($this->comes('}') || $this->comes(';') || $this->comes('!') || $this->comes(')') || $this->comes('\\'))) {
+			if (count($aStack) > 0) {
+				$bFoundDelimiter = false;
+				foreach ($aListDelimiters as $sDelimiter) {
+					if ($this->comes($sDelimiter)) {
+						array_push($aStack, $this->consume($sDelimiter));
+						$this->consumeWhiteSpace();
+						$bFoundDelimiter = true;
+						break;
+					}
+				}
+				if (!$bFoundDelimiter) {
+					//Whitespace was the list delimiter
+					array_push($aStack, ' ');
+				}
+			}
+			array_push($aStack, $this->parsePrimitiveValue());
+			$this->consumeWhiteSpace();
+		}
+		//Convert the list to list objects
+		foreach ($aListDelimiters as $sDelimiter) {
+			if (count($aStack) === 1) {
+				return $aStack[0];
+			}
+			$iStartPosition = null;
+			while (($iStartPosition = array_search($sDelimiter, $aStack, true)) !== false) {
+				$iLength = 2; //Number of elements to be joined
+				for ($i = $iStartPosition + 2; $i < count($aStack); $i+=2, ++$iLength) {
+					if ($sDelimiter !== $aStack[$i]) {
+						break;
+					}
+				}
+				$oList = new RuleValueList($sDelimiter, $this->iLineNo);
+				for ($i = $iStartPosition - 1; $i - $iStartPosition + 1 < $iLength * 2; $i+=2) {
+					$oList->addListComponent($aStack[$i]);
+				}
+				array_splice($aStack, $iStartPosition - 1, $iLength * 2 - 1, array($oList));
+			}
+		}
+		return $aStack[0];
+	}
+
+	private static function listDelimiterForRule($sRule) {
+		if (preg_match('/^font($|-)/', $sRule)) {
+			return array(',', '/', ' ');
+		}
+		return array(',', ' ', '/');
+	}
+
+	private function parsePrimitiveValue() {
+		$oValue = null;
+		$this->consumeWhiteSpace();
+		if (is_numeric($this->peek()) || ($this->comes('-.') && is_numeric($this->peek(1, 2))) || (($this->comes('-') || $this->comes('.')) && is_numeric($this->peek(1, 1)))) {
+			$oValue = $this->parseNumericValue();
+		} else if ($this->comes('#') || $this->comes('rgb', true) || $this->comes('hsl', true)) {
+			$oValue = $this->parseColorValue();
+		} else if ($this->comes('url', true)) {
+			$oValue = $this->parseURLValue();
+		} else if ($this->comes("'") || $this->comes('"')) {
+			$oValue = $this->parseStringValue();
+		} else if ($this->comes("progid:") && $this->oParserSettings->bLenientParsing) {
+			$oValue = $this->parseMicrosoftFilter();
+		} else {
+			$oValue = $this->parseIdentifier(true, false);
+		}
+		$this->consumeWhiteSpace();
+		return $oValue;
+	}
+
+	private function parseNumericValue($bForColor = false) {
+		$sSize = '';
+		if ($this->comes('-')) {
+			$sSize .= $this->consume('-');
+		}
+		while (is_numeric($this->peek()) || $this->comes('.')) {
+			if ($this->comes('.')) {
+				$sSize .= $this->consume('.');
+			} else {
+				$sSize .= $this->consume(1);
+			}
+		}
+
+		$sUnit = null;
+		foreach ($this->aSizeUnits as $iLength => &$aValues) {
+			$sKey = strtolower($this->peek($iLength));
+			if(array_key_exists($sKey, $aValues)) {
+				if (($sUnit = $aValues[$sKey]) !== null) {
+					$this->consume($iLength);
+					break;
+				}
+			}
+		}
+		return new Size(floatval($sSize), $sUnit, $bForColor, $this->iLineNo);
+	}
+
+	private function parseColorValue() {
+		$aColor = array();
+		if ($this->comes('#')) {
+			$this->consume('#');
+			$sValue = $this->parseIdentifier(false);
+			if ($this->strlen($sValue) === 3) {
+				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2];
+			}
+			$aColor = array('r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $this->iLineNo), 'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $this->iLineNo), 'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $this->iLineNo));
+		} else {
+			$sColorMode = $this->parseIdentifier(false);
+			$this->consumeWhiteSpace();
+			$this->consume('(');
+			$iLength = $this->strlen($sColorMode);
+			for ($i = 0; $i < $iLength; ++$i) {
+				$this->consumeWhiteSpace();
+				$aColor[$sColorMode[$i]] = $this->parseNumericValue(true);
+				$this->consumeWhiteSpace();
+				if ($i < ($iLength - 1)) {
+					$this->consume(',');
+				}
+			}
+			$this->consume(')');
+		}
+		return new Color($aColor, $this->iLineNo);
+	}
+
+	private function parseMicrosoftFilter() {
+		$sFunction = $this->consumeUntil('(', false, true);
+		$aArguments = $this->parseValue(array(',', '='));
+		return new CSSFunction($sFunction, $aArguments, ',', $this->iLineNo);
+	}
+
+	private function parseURLValue() {
+		$bUseUrl = $this->comes('url', true);
+		if ($bUseUrl) {
+			$this->consume('url');
+			$this->consumeWhiteSpace();
+			$this->consume('(');
+		}
+		$this->consumeWhiteSpace();
+		$oResult = new URL($this->parseStringValue(), $this->iLineNo);
+		if ($bUseUrl) {
+			$this->consumeWhiteSpace();
+			$this->consume(')');
+		}
+		return $oResult;
+	}
+
+	/**
+	 * Tests an identifier for a given value. Since identifiers are all keywords, they can be vendor-prefixed. We need to check for these versions too.
+	 */
+	private function identifierIs($sIdentifier, $sMatch) {
+		return (strcasecmp($sIdentifier, $sMatch) === 0)
+			?: preg_match("/^(-\\w+-)?$sMatch$/i", $sIdentifier) === 1;
+	}
+
+	private function comes($sString, $bCaseInsensitive = false) {
+		$sPeek = $this->peek(strlen($sString));
+		return ($sPeek == '')
+			? false
+			: $this->streql($sPeek, $sString, $bCaseInsensitive);
+	}
+
+	private function peek($iLength = 1, $iOffset = 0) {
+		$iOffset += $this->iCurrentPosition;
+		if ($iOffset >= $this->iLength) {
+			return '';
+		}
+		return $this->substr($iOffset, $iLength);
+	}
+
+	private function consume($mValue = 1) {
+		if (is_string($mValue)) {
+			$iLineCount = substr_count($mValue, "\n");
+			$iLength = $this->strlen($mValue);
+			if (!$this->streql($this->substr($this->iCurrentPosition, $iLength), $mValue)) {
+				throw new UnexpectedTokenException($mValue, $this->peek(max($iLength, 5)), $this->iLineNo);
+			}
+			$this->iLineNo += $iLineCount;
+			$this->iCurrentPosition += $this->strlen($mValue);
+			return $mValue;
+		} else {
+			if ($this->iCurrentPosition + $mValue > $this->iLength) {
+				throw new UnexpectedTokenException($mValue, $this->peek(5), 'count', $this->iLineNo);
+			}
+			$sResult = $this->substr($this->iCurrentPosition, $mValue);
+			$iLineCount = substr_count($sResult, "\n");
+			$this->iLineNo += $iLineCount;
+			$this->iCurrentPosition += $mValue;
+			return $sResult;
+		}
+	}
+
+	private function consumeExpression($mExpression) {
+		$aMatches = null;
+		if (preg_match($mExpression, $this->inputLeft(), $aMatches, PREG_OFFSET_CAPTURE) === 1) {
+			return $this->consume($aMatches[0][0]);
+		}
+		throw new UnexpectedTokenException($mExpression, $this->peek(5), 'expression', $this->iLineNo);
+	}
+
+	private function consumeWhiteSpace() {
+		$comments = array();
+		do {
+			while (preg_match('/\\s/isSu', $this->peek()) === 1) {
+				$this->consume(1);
+			}
+			if($this->oParserSettings->bLenientParsing) {
+				try {
+					$oComment = $this->consumeComment();
+				} catch(UnexpectedTokenException $e) {
+					// When we can’t find the end of a comment, we assume the document is finished.
+					$this->iCurrentPosition = $this->iLength;
+					return;
+				}
+			} else {
+				$oComment = $this->consumeComment();
+			}
+			if ($oComment !== false) {
+				$comments[] = $oComment;
+			}
+		} while($oComment !== false);
+		return $comments;
+	}
+
+	/**
+	 * @return false|Comment
+	 */
+	private function consumeComment() {
+		$mComment = false;
+		if ($this->comes('/*')) {
+			$iLineNo = $this->iLineNo;
+			$this->consume(1);
+			$mComment = '';
+			while (($char = $this->consume(1)) !== '') {
+				$mComment .= $char;
+				if ($this->comes('*/')) {
+					$this->consume(2);
+					break;
+				}
+			}
+		}
+
+		if ($mComment !== false) {
+			// We skip the * which was included in the comment.
+			return new Comment(substr($mComment, 1), $iLineNo);
+		}
+
+		return $mComment;
+	}
+
+	private function isEnd() {
+		return $this->iCurrentPosition >= $this->iLength;
+	}
+
+	private function consumeUntil($aEnd, $bIncludeEnd = false, $consumeEnd = false, array &$comments = array()) {
+		$aEnd = is_array($aEnd) ? $aEnd : array($aEnd);
+		$out = '';
+		$start = $this->iCurrentPosition;
+
+		while (($char = $this->consume(1)) !== '') {
+			if (in_array($char, $aEnd)) {
+				if ($bIncludeEnd) {
+					$out .= $char;
+				} elseif (!$consumeEnd) {
+					$this->iCurrentPosition -= $this->strlen($char);
+				}
+				return $out;
+			}
+			$out .= $char;
+			if ($comment = $this->consumeComment()) {
+				$comments[] = $comment;
+			}
+		}
+
+		$this->iCurrentPosition = $start;
+		throw new UnexpectedTokenException('One of ("'.implode('","', $aEnd).'")', $this->peek(5), 'search', $this->iLineNo);
+	}
+
+	private function inputLeft() {
+		return $this->substr($this->iCurrentPosition, -1);
+	}
+
+	private function substr($iStart, $iLength) {
+		if ($iLength < 0) {
+			$iLength = $this->iLength - $iStart + $iLength;
+		}
+		if ($iStart + $iLength > $this->iLength) {
+			$iLength = $this->iLength - $iStart;
+		}
+		$sResult = '';
+		while ($iLength > 0) {
+			$sResult .= $this->aText[$iStart];
+			$iStart++;
+			$iLength--;
+		}
+		return $sResult;
+	}
+
+	private function strlen($sString) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			return mb_strlen($sString, $this->sCharset);
+		} else {
+			return strlen($sString);
+		}
+	}
+
+	private function streql($sString1, $sString2, $bCaseInsensitive = true) {
+		if($bCaseInsensitive) {
+			return $this->strtolower($sString1) === $this->strtolower($sString2);
+		} else {
+			return $sString1 === $sString2;
+		}
+	}
+
+	private function strtolower($sString) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			return mb_strtolower($sString, $this->sCharset);
+		} else {
+			return strtolower($sString);
+		}
+	}
+
+	private function strsplit($sString) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			if ($this->streql($this->sCharset, 'utf-8')) {
+				return preg_split('//u', $sString, null, PREG_SPLIT_NO_EMPTY);
+			} else {
+				$iLength = mb_strlen($sString, $this->sCharset);
+				$aResult = array();
+				for ($i = 0; $i < $iLength; ++$i) {
+					$aResult[] = mb_substr($sString, $i, 1, $this->sCharset);
+				}
+				return $aResult;
+			}
+		} else {
+			if($sString === '') {
+				return array();
+			} else {
+				return str_split($sString);
+			}
+		}
+	}
+
+	private function strpos($sString, $sNeedle, $iOffset) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			return mb_strpos($sString, $sNeedle, $iOffset, $this->sCharset);
+		} else {
+			return strpos($sString, $sNeedle, $iOffset);
+		}
+	}
+
+}
diff --git a/lib/php-css-parser/Parsing/OutputException.php b/lib/php-css-parser/Parsing/OutputException.php
new file mode 100644
index 00000000000..1c811770430
--- /dev/null
+++ b/lib/php-css-parser/Parsing/OutputException.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Sabberworm\CSS\Parsing;
+
+/**
+* Thrown if the CSS parsers attempts to print something invalid
+*/
+class OutputException extends SourceException {
+	public function __construct($sMessage, $iLineNo = 0) {
+		parent::__construct($sMessage, $iLineNo);
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Parsing/SourceException.php b/lib/php-css-parser/Parsing/SourceException.php
new file mode 100644
index 00000000000..9bb9913847f
--- /dev/null
+++ b/lib/php-css-parser/Parsing/SourceException.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Sabberworm\CSS\Parsing;
+
+class SourceException extends \Exception {
+	private $iLineNo;
+	public function __construct($sMessage, $iLineNo = 0) {
+		$this->iLineNo = $iLineNo;
+		if (!empty($iLineNo)) {
+			$sMessage .= " [line no: $iLineNo]";
+		}
+		parent::__construct($sMessage);
+	}
+
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Parsing/UnexpectedTokenException.php b/lib/php-css-parser/Parsing/UnexpectedTokenException.php
new file mode 100644
index 00000000000..0ef881846a4
--- /dev/null
+++ b/lib/php-css-parser/Parsing/UnexpectedTokenException.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Sabberworm\CSS\Parsing;
+
+/**
+* Thrown if the CSS parsers encounters a token it did not expect
+*/
+class UnexpectedTokenException extends SourceException {
+	private $sExpected;
+	private $sFound;
+	// Possible values: literal, identifier, count, expression, search
+	private $sMatchType;
+
+	public function __construct($sExpected, $sFound, $sMatchType = 'literal', $iLineNo = 0) {
+		$this->sExpected = $sExpected;
+		$this->sFound = $sFound;
+		$this->sMatchType = $sMatchType;
+		$sMessage = "Token “{$sExpected}” ({$sMatchType}) not found. Got “{$sFound}”.";
+		if($this->sMatchType === 'search') {
+			$sMessage = "Search for “{$sExpected}” returned no results. Context: “{$sFound}”.";
+		} else if($this->sMatchType === 'count') {
+			$sMessage = "Next token was expected to have {$sExpected} chars. Context: “{$sFound}”.";
+		} else if($this->sMatchType === 'identifier') {
+			$sMessage = "Identifier expected. Got “{$sFound}”";
+		} else if($this->sMatchType === 'custom') {
+			$sMessage = trim("$sExpected $sFound");
+		}
+
+		parent::__construct($sMessage, $iLineNo);
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Property/AtRule.php b/lib/php-css-parser/Property/AtRule.php
new file mode 100644
index 00000000000..de3eea19259
--- /dev/null
+++ b/lib/php-css-parser/Property/AtRule.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Sabberworm\CSS\Property;
+
+use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\Comment\Commentable;
+
+interface AtRule extends Renderable, Commentable {
+	const BLOCK_RULES = 'media/document/supports/region-style/font-feature-values';
+	// Since there are more set rules than block rules, we’re whitelisting the block rules and have anything else be treated as a set rule.
+	const SET_RULES = 'font-face/counter-style/page/swash/styleset/annotation'; //…and more font-specific ones (to be used inside font-feature-values)
+	
+	public function atRuleName();
+	public function atRuleArgs();
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Property/CSSNamespace.php b/lib/php-css-parser/Property/CSSNamespace.php
new file mode 100644
index 00000000000..7c0dee15981
--- /dev/null
+++ b/lib/php-css-parser/Property/CSSNamespace.php
@@ -0,0 +1,75 @@
+<?php
+
+namespace Sabberworm\CSS\Property;
+
+/**
+* CSSNamespace represents an @namespace rule.
+*/
+class CSSNamespace implements AtRule {
+	private $mUrl;
+	private $sPrefix;
+	private $iLineNo;
+	protected $aComments;
+	
+	public function __construct($mUrl, $sPrefix = null, $iLineNo = 0) {
+		$this->mUrl = $mUrl;
+		$this->sPrefix = $sPrefix;
+		$this->iLineNo = $iLineNo;
+		$this->aComments = array();
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		return '@namespace '.($this->sPrefix === null ? '' : $this->sPrefix.' ').$this->mUrl->render($oOutputFormat).';';
+	}
+	
+	public function getUrl() {
+		return $this->mUrl;
+	}
+
+	public function getPrefix() {
+		return $this->sPrefix;
+	}
+
+	public function setUrl($mUrl) {
+		$this->mUrl = $mUrl;
+	}
+
+	public function setPrefix($sPrefix) {
+		$this->sPrefix = $sPrefix;
+	}
+
+	public function atRuleName() {
+		return 'namespace';
+	}
+
+	public function atRuleArgs() {
+		$aResult = array($this->mUrl);
+		if($this->sPrefix) {
+			array_unshift($aResult, $this->sPrefix);
+		}
+		return $aResult;
+	}
+
+	public function addComments(array $aComments) {
+		$this->aComments = array_merge($this->aComments, $aComments);
+	}
+
+	public function getComments() {
+		return $this->aComments;
+	}
+
+	public function setComments(array $aComments) {
+		$this->aComments = $aComments;
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Property/Charset.php b/lib/php-css-parser/Property/Charset.php
new file mode 100644
index 00000000000..61c6ebc5b63
--- /dev/null
+++ b/lib/php-css-parser/Property/Charset.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace Sabberworm\CSS\Property;
+
+/**
+ * Class representing an @charset rule.
+ * The following restrictions apply:
+ * • May not be found in any CSSList other than the Document.
+ * • May only appear at the very top of a Document’s contents.
+ * • Must not appear more than once.
+ */
+class Charset implements AtRule {
+
+	private $sCharset;
+	protected $iLineNo;
+	protected $aComment;
+
+	public function __construct($sCharset, $iLineNo = 0) {
+		$this->sCharset = $sCharset;
+		$this->iLineNo = $iLineNo;
+		$this->aComments = array();
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	public function setCharset($sCharset) {
+		$this->sCharset = $sCharset;
+	}
+
+	public function getCharset() {
+		return $this->sCharset;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		return "@charset {$this->sCharset->render($oOutputFormat)};";
+	}
+
+	public function atRuleName() {
+		return 'charset';
+	}
+
+	public function atRuleArgs() {
+		return $this->sCharset;
+	}
+
+	public function addComments(array $aComments) {
+		$this->aComments = array_merge($this->aComments, $aComments);
+	}
+
+	public function getComments() {
+		return $this->aComments;
+	}
+
+	public function setComments(array $aComments) {
+		$this->aComments = $aComments;
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Property/Import.php b/lib/php-css-parser/Property/Import.php
new file mode 100644
index 00000000000..4d40f5a04ca
--- /dev/null
+++ b/lib/php-css-parser/Property/Import.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Sabberworm\CSS\Property;
+
+use Sabberworm\CSS\Value\URL;
+
+/**
+* Class representing an @import rule.
+*/
+class Import implements AtRule {
+	private $oLocation;
+	private $sMediaQuery;
+	protected $iLineNo;
+	protected $aComments;
+	
+	public function __construct(URL $oLocation, $sMediaQuery, $iLineNo = 0) {
+		$this->oLocation = $oLocation;
+		$this->sMediaQuery = $sMediaQuery;
+		$this->iLineNo = $iLineNo;
+		$this->aComments = array();
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	public function setLocation($oLocation) {
+			$this->oLocation = $oLocation;
+	}
+
+	public function getLocation() {
+			return $this->oLocation;
+	}
+	
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		return "@import ".$this->oLocation->render($oOutputFormat).($this->sMediaQuery === null ? '' : ' '.$this->sMediaQuery).';';
+	}
+
+	public function atRuleName() {
+		return 'import';
+	}
+
+	public function atRuleArgs() {
+		$aResult = array($this->oLocation);
+		if($this->sMediaQuery) {
+			array_push($aResult, $this->sMediaQuery);
+		}
+		return $aResult;
+	}
+
+	public function addComments(array $aComments) {
+		$this->aComments = array_merge($this->aComments, $aComments);
+	}
+
+	public function getComments() {
+		return $this->aComments;
+	}
+
+	public function setComments(array $aComments) {
+		$this->aComments = $aComments;
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Property/Selector.php b/lib/php-css-parser/Property/Selector.php
new file mode 100644
index 00000000000..d84171f5ef1
--- /dev/null
+++ b/lib/php-css-parser/Property/Selector.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace Sabberworm\CSS\Property;
+
+/**
+ * Class representing a single CSS selector. Selectors have to be split by the comma prior to being passed into this class.
+ */
+class Selector {
+
+	//Regexes for specificity calculations
+	const NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX = '/
+	(\.[\w]+)                   # classes
+	|
+	\[(\w+)                     # attributes
+	|
+	(\:(                        # pseudo classes
+		link|visited|active
+		|hover|focus
+		|lang
+		|target
+		|enabled|disabled|checked|indeterminate
+		|root
+		|nth-child|nth-last-child|nth-of-type|nth-last-of-type
+		|first-child|last-child|first-of-type|last-of-type
+		|only-child|only-of-type
+		|empty|contains
+	))
+	/ix';
+
+	const ELEMENTS_AND_PSEUDO_ELEMENTS_RX = '/
+	((^|[\s\+\>\~]+)[\w]+   # elements
+	|
+	\:{1,2}(                # pseudo-elements
+		after|before|first-letter|first-line|selection
+	))
+	/ix';
+
+	private $sSelector;
+	private $iSpecificity;
+
+	public function __construct($sSelector, $bCalculateSpecificity = false) {
+		$this->setSelector($sSelector);
+		if ($bCalculateSpecificity) {
+			$this->getSpecificity();
+		}
+	}
+
+	public function getSelector() {
+		return $this->sSelector;
+	}
+
+	public function setSelector($sSelector) {
+		$this->sSelector = trim($sSelector);
+		$this->iSpecificity = null;
+	}
+
+	public function __toString() {
+		return $this->getSelector();
+	}
+
+	public function getSpecificity() {
+		if ($this->iSpecificity === null) {
+			$a = 0;
+			/// @todo should exclude \# as well as "#"
+			$aMatches = null;
+			$b = substr_count($this->sSelector, '#');
+			$c = preg_match_all(self::NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX, $this->sSelector, $aMatches);
+			$d = preg_match_all(self::ELEMENTS_AND_PSEUDO_ELEMENTS_RX, $this->sSelector, $aMatches);
+			$this->iSpecificity = ($a * 1000) + ($b * 100) + ($c * 10) + $d;
+		}
+		return $this->iSpecificity;
+	}
+
+}
diff --git a/lib/php-css-parser/Renderable.php b/lib/php-css-parser/Renderable.php
new file mode 100644
index 00000000000..3ac06652e51
--- /dev/null
+++ b/lib/php-css-parser/Renderable.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Sabberworm\CSS;
+
+interface Renderable {
+	public function __toString();
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat);
+	public function getLineNo();
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Rule/Rule.php b/lib/php-css-parser/Rule/Rule.php
new file mode 100644
index 00000000000..3e4853753b9
--- /dev/null
+++ b/lib/php-css-parser/Rule/Rule.php
@@ -0,0 +1,197 @@
+<?php
+
+namespace Sabberworm\CSS\Rule;
+
+use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\Value\RuleValueList;
+use Sabberworm\CSS\Value\Value;
+use Sabberworm\CSS\Comment\Commentable;
+
+/**
+ * RuleSets contains Rule objects which always have a key and a value.
+ * In CSS, Rules are expressed as follows: “key: value[0][0] value[0][1], value[1][0] value[1][1];”
+ */
+class Rule implements Renderable, Commentable {
+
+	private $sRule;
+	private $mValue;
+	private $bIsImportant;
+	private $aIeHack;
+	protected $iLineNo;
+	protected $aComments;
+
+	public function __construct($sRule, $iLineNo = 0) {
+		$this->sRule = $sRule;
+		$this->mValue = null;
+		$this->bIsImportant = false;
+		$this->aIeHack = array();
+		$this->iLineNo = $iLineNo;
+		$this->aComments = array();
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	public function setRule($sRule) {
+		$this->sRule = $sRule;
+	}
+
+	public function getRule() {
+		return $this->sRule;
+	}
+
+	public function getValue() {
+		return $this->mValue;
+	}
+
+	public function setValue($mValue) {
+		$this->mValue = $mValue;
+	}
+
+	/**
+	 *	@deprecated Old-Style 2-dimensional array given. Retained for (some) backwards-compatibility. Use setValue() instead and wrapp the value inside a RuleValueList if necessary.
+	 */
+	public function setValues($aSpaceSeparatedValues) {
+		$oSpaceSeparatedList = null;
+		if (count($aSpaceSeparatedValues) > 1) {
+			$oSpaceSeparatedList = new RuleValueList(' ', $this->iLineNo);
+		}
+		foreach ($aSpaceSeparatedValues as $aCommaSeparatedValues) {
+			$oCommaSeparatedList = null;
+			if (count($aCommaSeparatedValues) > 1) {
+				$oCommaSeparatedList = new RuleValueList(',', $this->iLineNo);
+			}
+			foreach ($aCommaSeparatedValues as $mValue) {
+				if (!$oSpaceSeparatedList && !$oCommaSeparatedList) {
+					$this->mValue = $mValue;
+					return $mValue;
+				}
+				if ($oCommaSeparatedList) {
+					$oCommaSeparatedList->addListComponent($mValue);
+				} else {
+					$oSpaceSeparatedList->addListComponent($mValue);
+				}
+			}
+			if (!$oSpaceSeparatedList) {
+				$this->mValue = $oCommaSeparatedList;
+				return $oCommaSeparatedList;
+			} else {
+				$oSpaceSeparatedList->addListComponent($oCommaSeparatedList);
+			}
+		}
+		$this->mValue = $oSpaceSeparatedList;
+		return $oSpaceSeparatedList;
+	}
+
+	/**
+	 *	@deprecated Old-Style 2-dimensional array returned. Retained for (some) backwards-compatibility. Use getValue() instead and check for the existance of a (nested set of) ValueList object(s).
+	 */
+	public function getValues() {
+		if (!$this->mValue instanceof RuleValueList) {
+			return array(array($this->mValue));
+		}
+		if ($this->mValue->getListSeparator() === ',') {
+			return array($this->mValue->getListComponents());
+		}
+		$aResult = array();
+		foreach ($this->mValue->getListComponents() as $mValue) {
+			if (!$mValue instanceof RuleValueList || $mValue->getListSeparator() !== ',') {
+				$aResult[] = array($mValue);
+				continue;
+			}
+			if ($this->mValue->getListSeparator() === ' ' || count($aResult) === 0) {
+				$aResult[] = array();
+			}
+			foreach ($mValue->getListComponents() as $mValue) {
+				$aResult[count($aResult) - 1][] = $mValue;
+			}
+		}
+		return $aResult;
+	}
+
+	/**
+	 * Adds a value to the existing value. Value will be appended if a RuleValueList exists of the given type. Otherwise, the existing value will be wrapped by one.
+	 */
+	public function addValue($mValue, $sType = ' ') {
+		if (!is_array($mValue)) {
+			$mValue = array($mValue);
+		}
+		if (!$this->mValue instanceof RuleValueList || $this->mValue->getListSeparator() !== $sType) {
+			$mCurrentValue = $this->mValue;
+			$this->mValue = new RuleValueList($sType, $this->iLineNo);
+			if ($mCurrentValue) {
+				$this->mValue->addListComponent($mCurrentValue);
+			}
+		}
+		foreach ($mValue as $mValueItem) {
+			$this->mValue->addListComponent($mValueItem);
+		}
+	}
+
+	public function addIeHack($iModifier) {
+		$this->aIeHack[] = $iModifier;
+	}
+
+	public function setIeHack(array $aModifiers) {
+		$this->aIeHack = $aModifiers;
+	}
+
+	public function getIeHack() {
+		return $this->aIeHack;
+	}
+
+	public function setIsImportant($bIsImportant) {
+		$this->bIsImportant = $bIsImportant;
+	}
+
+	public function getIsImportant() {
+		return $this->bIsImportant;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sResult = "{$this->sRule}:{$oOutputFormat->spaceAfterRuleName()}";
+		if ($this->mValue instanceof Value) { //Can also be a ValueList
+			$sResult .= $this->mValue->render($oOutputFormat);
+		} else {
+			$sResult .= $this->mValue;
+		}
+		if (!empty($this->aIeHack)) {
+			$sResult .= ' \\' . implode('\\', $this->aIeHack);
+		}
+		if ($this->bIsImportant) {
+			$sResult .= ' !important';
+		}
+		$sResult .= ';';
+		return $sResult;
+	}
+
+	/**
+	 * @param array $aComments Array of comments.
+	 */
+	public function addComments(array $aComments) {
+		$this->aComments = array_merge($this->aComments, $aComments);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getComments() {
+		return $this->aComments;
+	}
+
+	/**
+	 * @param array $aComments Array containing Comment objects.
+	 */
+	public function setComments(array $aComments) {
+		$this->aComments = $aComments;
+	}
+
+}
diff --git a/lib/php-css-parser/RuleSet/AtRuleSet.php b/lib/php-css-parser/RuleSet/AtRuleSet.php
new file mode 100644
index 00000000000..a1042a95aec
--- /dev/null
+++ b/lib/php-css-parser/RuleSet/AtRuleSet.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Sabberworm\CSS\RuleSet;
+
+use Sabberworm\CSS\Property\AtRule;
+
+/**
+ * A RuleSet constructed by an unknown @-rule. @font-face rules are rendered into AtRuleSet objects.
+ */
+class AtRuleSet extends RuleSet implements AtRule {
+
+	private $sType;
+	private $sArgs;
+
+	public function __construct($sType, $sArgs = '', $iLineNo = 0) {
+		parent::__construct($iLineNo);
+		$this->sType = $sType;
+		$this->sArgs = $sArgs;
+	}
+
+	public function atRuleName() {
+		return $this->sType;
+	}
+
+	public function atRuleArgs() {
+		return $this->sArgs;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sArgs = $this->sArgs;
+		if($sArgs) {
+			$sArgs = ' ' . $sArgs;
+		}
+		$sResult = "@{$this->sType}$sArgs{$oOutputFormat->spaceBeforeOpeningBrace()}{";
+		$sResult .= parent::render($oOutputFormat);
+		$sResult .= '}';
+		return $sResult;
+	}
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/RuleSet/DeclarationBlock.php b/lib/php-css-parser/RuleSet/DeclarationBlock.php
new file mode 100644
index 00000000000..e18f5d82984
--- /dev/null
+++ b/lib/php-css-parser/RuleSet/DeclarationBlock.php
@@ -0,0 +1,608 @@
+<?php
+
+namespace Sabberworm\CSS\RuleSet;
+
+use Sabberworm\CSS\Property\Selector;
+use Sabberworm\CSS\Rule\Rule;
+use Sabberworm\CSS\Value\RuleValueList;
+use Sabberworm\CSS\Value\Value;
+use Sabberworm\CSS\Value\Size;
+use Sabberworm\CSS\Value\Color;
+use Sabberworm\CSS\Value\URL;
+use Sabberworm\CSS\Parsing\OutputException;
+
+/**
+ * Declaration blocks are the parts of a css file which denote the rules belonging to a selector.
+ * Declaration blocks usually appear directly inside a Document or another CSSList (mostly a MediaQuery).
+ */
+class DeclarationBlock extends RuleSet {
+
+	private $aSelectors;
+
+	public function __construct($iLineNo = 0) {
+		parent::__construct($iLineNo);
+		$this->aSelectors = array();
+	}
+
+	public function setSelectors($mSelector) {
+		if (is_array($mSelector)) {
+			$this->aSelectors = $mSelector;
+		} else {
+			$this->aSelectors = explode(',', $mSelector);
+		}
+		foreach ($this->aSelectors as $iKey => $mSelector) {
+			if (!($mSelector instanceof Selector)) {
+				$this->aSelectors[$iKey] = new Selector($mSelector);
+			}
+		}
+	}
+
+	// remove one of the selector of the block
+	public function removeSelector($mSelector) {
+		if($mSelector instanceof Selector) {
+			$mSelector = $mSelector->getSelector();
+		}
+		foreach($this->aSelectors as $iKey => $oSelector) {
+			if($oSelector->getSelector() === $mSelector) {
+				unset($this->aSelectors[$iKey]);
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * @deprecated use getSelectors()
+	 */
+	public function getSelector() {
+		return $this->getSelectors();
+	}
+
+	/**
+	 * @deprecated use setSelectors()
+	 */
+	public function setSelector($mSelector) {
+		$this->setSelectors($mSelector);
+	}
+
+	public function getSelectors() {
+		return $this->aSelectors;
+	}
+
+	/**
+	 * Split shorthand declarations (e.g. +margin+ or +font+) into their constituent parts.
+	 * */
+	public function expandShorthands() {
+		// border must be expanded before dimensions
+		$this->expandBorderShorthand();
+		$this->expandDimensionsShorthand();
+		$this->expandFontShorthand();
+		$this->expandBackgroundShorthand();
+		$this->expandListStyleShorthand();
+	}
+
+	/**
+	 * Create shorthand declarations (e.g. +margin+ or +font+) whenever possible.
+	 * */
+	public function createShorthands() {
+		$this->createBackgroundShorthand();
+		$this->createDimensionsShorthand();
+		// border must be shortened after dimensions 
+		$this->createBorderShorthand();
+		$this->createFontShorthand();
+		$this->createListStyleShorthand();
+	}
+
+	/**
+	 * Split shorthand border declarations (e.g. <tt>border: 1px red;</tt>)
+	 * Additional splitting happens in expandDimensionsShorthand
+	 * Multiple borders are not yet supported as of 3
+	 * */
+	public function expandBorderShorthand() {
+		$aBorderRules = array(
+			'border', 'border-left', 'border-right', 'border-top', 'border-bottom'
+		);
+		$aBorderSizes = array(
+			'thin', 'medium', 'thick'
+		);
+		$aRules = $this->getRulesAssoc();
+		foreach ($aBorderRules as $sBorderRule) {
+			if (!isset($aRules[$sBorderRule]))
+				continue;
+			$oRule = $aRules[$sBorderRule];
+			$mRuleValue = $oRule->getValue();
+			$aValues = array();
+			if (!$mRuleValue instanceof RuleValueList) {
+				$aValues[] = $mRuleValue;
+			} else {
+				$aValues = $mRuleValue->getListComponents();
+			}
+			foreach ($aValues as $mValue) {
+				if ($mValue instanceof Value) {
+					$mNewValue = clone $mValue;
+				} else {
+					$mNewValue = $mValue;
+				}
+				if ($mValue instanceof Size) {
+					$sNewRuleName = $sBorderRule . "-width";
+				} else if ($mValue instanceof Color) {
+					$sNewRuleName = $sBorderRule . "-color";
+				} else {
+					if (in_array($mValue, $aBorderSizes)) {
+						$sNewRuleName = $sBorderRule . "-width";
+					} else/* if(in_array($mValue, $aBorderStyles)) */ {
+						$sNewRuleName = $sBorderRule . "-style";
+					}
+				}
+				$oNewRule = new Rule($sNewRuleName, $this->iLineNo);
+				$oNewRule->setIsImportant($oRule->getIsImportant());
+				$oNewRule->addValue(array($mNewValue));
+				$this->addRule($oNewRule);
+			}
+			$this->removeRule($sBorderRule);
+		}
+	}
+
+	/**
+	 * Split shorthand dimensional declarations (e.g. <tt>margin: 0px auto;</tt>)
+	 * into their constituent parts.
+	 * Handles margin, padding, border-color, border-style and border-width.
+	 * */
+	public function expandDimensionsShorthand() {
+		$aExpansions = array(
+			'margin' => 'margin-%s',
+			'padding' => 'padding-%s',
+			'border-color' => 'border-%s-color',
+			'border-style' => 'border-%s-style',
+			'border-width' => 'border-%s-width'
+		);
+		$aRules = $this->getRulesAssoc();
+		foreach ($aExpansions as $sProperty => $sExpanded) {
+			if (!isset($aRules[$sProperty]))
+				continue;
+			$oRule = $aRules[$sProperty];
+			$mRuleValue = $oRule->getValue();
+			$aValues = array();
+			if (!$mRuleValue instanceof RuleValueList) {
+				$aValues[] = $mRuleValue;
+			} else {
+				$aValues = $mRuleValue->getListComponents();
+			}
+			$top = $right = $bottom = $left = null;
+			switch (count($aValues)) {
+				case 1:
+					$top = $right = $bottom = $left = $aValues[0];
+					break;
+				case 2:
+					$top = $bottom = $aValues[0];
+					$left = $right = $aValues[1];
+					break;
+				case 3:
+					$top = $aValues[0];
+					$left = $right = $aValues[1];
+					$bottom = $aValues[2];
+					break;
+				case 4:
+					$top = $aValues[0];
+					$right = $aValues[1];
+					$bottom = $aValues[2];
+					$left = $aValues[3];
+					break;
+			}
+			foreach (array('top', 'right', 'bottom', 'left') as $sPosition) {
+				$oNewRule = new Rule(sprintf($sExpanded, $sPosition), $this->iLineNo);
+				$oNewRule->setIsImportant($oRule->getIsImportant());
+				$oNewRule->addValue(${$sPosition});
+				$this->addRule($oNewRule);
+			}
+			$this->removeRule($sProperty);
+		}
+	}
+
+	/**
+	 * Convert shorthand font declarations
+	 * (e.g. <tt>font: 300 italic 11px/14px verdana, helvetica, sans-serif;</tt>)
+	 * into their constituent parts.
+	 * */
+	public function expandFontShorthand() {
+		$aRules = $this->getRulesAssoc();
+		if (!isset($aRules['font']))
+			return;
+		$oRule = $aRules['font'];
+		// reset properties to 'normal' per http://www.w3.org/TR/21/fonts.html#font-shorthand
+		$aFontProperties = array(
+			'font-style' => 'normal',
+			'font-variant' => 'normal',
+			'font-weight' => 'normal',
+			'font-size' => 'normal',
+			'line-height' => 'normal'
+		);
+		$mRuleValue = $oRule->getValue();
+		$aValues = array();
+		if (!$mRuleValue instanceof RuleValueList) {
+			$aValues[] = $mRuleValue;
+		} else {
+			$aValues = $mRuleValue->getListComponents();
+		}
+		foreach ($aValues as $mValue) {
+			if (!$mValue instanceof Value) {
+				$mValue = mb_strtolower($mValue);
+			}
+			if (in_array($mValue, array('normal', 'inherit'))) {
+				foreach (array('font-style', 'font-weight', 'font-variant') as $sProperty) {
+					if (!isset($aFontProperties[$sProperty])) {
+						$aFontProperties[$sProperty] = $mValue;
+					}
+				}
+			} else if (in_array($mValue, array('italic', 'oblique'))) {
+				$aFontProperties['font-style'] = $mValue;
+			} else if ($mValue == 'small-caps') {
+				$aFontProperties['font-variant'] = $mValue;
+			} else if (
+					in_array($mValue, array('bold', 'bolder', 'lighter'))
+					|| ($mValue instanceof Size
+					&& in_array($mValue->getSize(), range(100, 900, 100)))
+			) {
+				$aFontProperties['font-weight'] = $mValue;
+			} else if ($mValue instanceof RuleValueList && $mValue->getListSeparator() == '/') {
+				list($oSize, $oHeight) = $mValue->getListComponents();
+				$aFontProperties['font-size'] = $oSize;
+				$aFontProperties['line-height'] = $oHeight;
+			} else if ($mValue instanceof Size && $mValue->getUnit() !== null) {
+				$aFontProperties['font-size'] = $mValue;
+			} else {
+				$aFontProperties['font-family'] = $mValue;
+			}
+		}
+		foreach ($aFontProperties as $sProperty => $mValue) {
+			$oNewRule = new Rule($sProperty, $this->iLineNo);
+			$oNewRule->addValue($mValue);
+			$oNewRule->setIsImportant($oRule->getIsImportant());
+			$this->addRule($oNewRule);
+		}
+		$this->removeRule('font');
+	}
+
+	/*
+	 * Convert shorthand background declarations
+	 * (e.g. <tt>background: url("chess.png") gray 50% repeat fixed;</tt>)
+	 * into their constituent parts.
+	 * @see http://www.w3.org/TR/21/colors.html#propdef-background
+	 * */
+
+	public function expandBackgroundShorthand() {
+		$aRules = $this->getRulesAssoc();
+		if (!isset($aRules['background']))
+			return;
+		$oRule = $aRules['background'];
+		$aBgProperties = array(
+			'background-color' => array('transparent'), 'background-image' => array('none'),
+			'background-repeat' => array('repeat'), 'background-attachment' => array('scroll'),
+			'background-position' => array(new Size(0, '%', null, false, $this->iLineNo), new Size(0, '%', null, false, $this->iLineNo))
+		);
+		$mRuleValue = $oRule->getValue();
+		$aValues = array();
+		if (!$mRuleValue instanceof RuleValueList) {
+			$aValues[] = $mRuleValue;
+		} else {
+			$aValues = $mRuleValue->getListComponents();
+		}
+		if (count($aValues) == 1 && $aValues[0] == 'inherit') {
+			foreach ($aBgProperties as $sProperty => $mValue) {
+				$oNewRule = new Rule($sProperty, $this->iLineNo);
+				$oNewRule->addValue('inherit');
+				$oNewRule->setIsImportant($oRule->getIsImportant());
+				$this->addRule($oNewRule);
+			}
+			$this->removeRule('background');
+			return;
+		}
+		$iNumBgPos = 0;
+		foreach ($aValues as $mValue) {
+			if (!$mValue instanceof Value) {
+				$mValue = mb_strtolower($mValue);
+			}
+			if ($mValue instanceof URL) {
+				$aBgProperties['background-image'] = $mValue;
+			} else if ($mValue instanceof Color) {
+				$aBgProperties['background-color'] = $mValue;
+			} else if (in_array($mValue, array('scroll', 'fixed'))) {
+				$aBgProperties['background-attachment'] = $mValue;
+			} else if (in_array($mValue, array('repeat', 'no-repeat', 'repeat-x', 'repeat-y'))) {
+				$aBgProperties['background-repeat'] = $mValue;
+			} else if (in_array($mValue, array('left', 'center', 'right', 'top', 'bottom'))
+					|| $mValue instanceof Size
+			) {
+				if ($iNumBgPos == 0) {
+					$aBgProperties['background-position'][0] = $mValue;
+					$aBgProperties['background-position'][1] = 'center';
+				} else {
+					$aBgProperties['background-position'][$iNumBgPos] = $mValue;
+				}
+				$iNumBgPos++;
+			}
+		}
+		foreach ($aBgProperties as $sProperty => $mValue) {
+			$oNewRule = new Rule($sProperty, $this->iLineNo);
+			$oNewRule->setIsImportant($oRule->getIsImportant());
+			$oNewRule->addValue($mValue);
+			$this->addRule($oNewRule);
+		}
+		$this->removeRule('background');
+	}
+
+	public function expandListStyleShorthand() {
+		$aListProperties = array(
+			'list-style-type' => 'disc',
+			'list-style-position' => 'outside',
+			'list-style-image' => 'none'
+		);
+		$aListStyleTypes = array(
+			'none', 'disc', 'circle', 'square', 'decimal-leading-zero', 'decimal',
+			'lower-roman', 'upper-roman', 'lower-greek', 'lower-alpha', 'lower-latin',
+			'upper-alpha', 'upper-latin', 'hebrew', 'armenian', 'georgian', 'cjk-ideographic',
+			'hiragana', 'hira-gana-iroha', 'katakana-iroha', 'katakana'
+		);
+		$aListStylePositions = array(
+			'inside', 'outside'
+		);
+		$aRules = $this->getRulesAssoc();
+		if (!isset($aRules['list-style']))
+			return;
+		$oRule = $aRules['list-style'];
+		$mRuleValue = $oRule->getValue();
+		$aValues = array();
+		if (!$mRuleValue instanceof RuleValueList) {
+			$aValues[] = $mRuleValue;
+		} else {
+			$aValues = $mRuleValue->getListComponents();
+		}
+		if (count($aValues) == 1 && $aValues[0] == 'inherit') {
+			foreach ($aListProperties as $sProperty => $mValue) {
+				$oNewRule = new Rule($sProperty, $this->iLineNo);
+				$oNewRule->addValue('inherit');
+				$oNewRule->setIsImportant($oRule->getIsImportant());
+				$this->addRule($oNewRule);
+			}
+			$this->removeRule('list-style');
+			return;
+		}
+		foreach ($aValues as $mValue) {
+			if (!$mValue instanceof Value) {
+				$mValue = mb_strtolower($mValue);
+			}
+			if ($mValue instanceof Url) {
+				$aListProperties['list-style-image'] = $mValue;
+			} else if (in_array($mValue, $aListStyleTypes)) {
+				$aListProperties['list-style-types'] = $mValue;
+			} else if (in_array($mValue, $aListStylePositions)) {
+				$aListProperties['list-style-position'] = $mValue;
+			}
+		}
+		foreach ($aListProperties as $sProperty => $mValue) {
+			$oNewRule = new Rule($sProperty, $this->iLineNo);
+			$oNewRule->setIsImportant($oRule->getIsImportant());
+			$oNewRule->addValue($mValue);
+			$this->addRule($oNewRule);
+		}
+		$this->removeRule('list-style');
+	}
+
+	public function createShorthandProperties(array $aProperties, $sShorthand) {
+		$aRules = $this->getRulesAssoc();
+		$aNewValues = array();
+		foreach ($aProperties as $sProperty) {
+			if (!isset($aRules[$sProperty]))
+				continue;
+			$oRule = $aRules[$sProperty];
+			if (!$oRule->getIsImportant()) {
+				$mRuleValue = $oRule->getValue();
+				$aValues = array();
+				if (!$mRuleValue instanceof RuleValueList) {
+					$aValues[] = $mRuleValue;
+				} else {
+					$aValues = $mRuleValue->getListComponents();
+				}
+				foreach ($aValues as $mValue) {
+					$aNewValues[] = $mValue;
+				}
+				$this->removeRule($sProperty);
+			}
+		}
+		if (count($aNewValues)) {
+			$oNewRule = new Rule($sShorthand, $this->iLineNo);
+			foreach ($aNewValues as $mValue) {
+				$oNewRule->addValue($mValue);
+			}
+			$this->addRule($oNewRule);
+		}
+	}
+
+	public function createBackgroundShorthand() {
+		$aProperties = array(
+			'background-color', 'background-image', 'background-repeat',
+			'background-position', 'background-attachment'
+		);
+		$this->createShorthandProperties($aProperties, 'background');
+	}
+
+	public function createListStyleShorthand() {
+		$aProperties = array(
+			'list-style-type', 'list-style-position', 'list-style-image'
+		);
+		$this->createShorthandProperties($aProperties, 'list-style');
+	}
+
+	/**
+	 * Combine border-color, border-style and border-width into border
+	 * Should be run after create_dimensions_shorthand!
+	 * */
+	public function createBorderShorthand() {
+		$aProperties = array(
+			'border-width', 'border-style', 'border-color'
+		);
+		$this->createShorthandProperties($aProperties, 'border');
+	}
+
+	/*
+	 * Looks for long format CSS dimensional properties
+	 * (margin, padding, border-color, border-style and border-width) 
+	 * and converts them into shorthand CSS properties.
+	 * */
+
+	public function createDimensionsShorthand() {
+		$aPositions = array('top', 'right', 'bottom', 'left');
+		$aExpansions = array(
+			'margin' => 'margin-%s',
+			'padding' => 'padding-%s',
+			'border-color' => 'border-%s-color',
+			'border-style' => 'border-%s-style',
+			'border-width' => 'border-%s-width'
+		);
+		$aRules = $this->getRulesAssoc();
+		foreach ($aExpansions as $sProperty => $sExpanded) {
+			$aFoldable = array();
+			foreach ($aRules as $sRuleName => $oRule) {
+				foreach ($aPositions as $sPosition) {
+					if ($sRuleName == sprintf($sExpanded, $sPosition)) {
+						$aFoldable[$sRuleName] = $oRule;
+					}
+				}
+			}
+			// All four dimensions must be present
+			if (count($aFoldable) == 4) {
+				$aValues = array();
+				foreach ($aPositions as $sPosition) {
+					$oRule = $aRules[sprintf($sExpanded, $sPosition)];
+					$mRuleValue = $oRule->getValue();
+					$aRuleValues = array();
+					if (!$mRuleValue instanceof RuleValueList) {
+						$aRuleValues[] = $mRuleValue;
+					} else {
+						$aRuleValues = $mRuleValue->getListComponents();
+					}
+					$aValues[$sPosition] = $aRuleValues;
+				}
+				$oNewRule = new Rule($sProperty, $this->iLineNo);
+				if ((string) $aValues['left'][0] == (string) $aValues['right'][0]) {
+					if ((string) $aValues['top'][0] == (string) $aValues['bottom'][0]) {
+						if ((string) $aValues['top'][0] == (string) $aValues['left'][0]) {
+							// All 4 sides are equal
+							$oNewRule->addValue($aValues['top']);
+						} else {
+							// Top and bottom are equal, left and right are equal
+							$oNewRule->addValue($aValues['top']);
+							$oNewRule->addValue($aValues['left']);
+						}
+					} else {
+						// Only left and right are equal
+						$oNewRule->addValue($aValues['top']);
+						$oNewRule->addValue($aValues['left']);
+						$oNewRule->addValue($aValues['bottom']);
+					}
+				} else {
+					// No sides are equal 
+					$oNewRule->addValue($aValues['top']);
+					$oNewRule->addValue($aValues['left']);
+					$oNewRule->addValue($aValues['bottom']);
+					$oNewRule->addValue($aValues['right']);
+				}
+				$this->addRule($oNewRule);
+				foreach ($aPositions as $sPosition) {
+					$this->removeRule(sprintf($sExpanded, $sPosition));
+				}
+			}
+		}
+	}
+
+	/**
+	 * Looks for long format CSS font properties (e.g. <tt>font-weight</tt>) and 
+	 * tries to convert them into a shorthand CSS <tt>font</tt> property. 
+	 * At least font-size AND font-family must be present in order to create a shorthand declaration.
+	 * */
+	public function createFontShorthand() {
+		$aFontProperties = array(
+			'font-style', 'font-variant', 'font-weight', 'font-size', 'line-height', 'font-family'
+		);
+		$aRules = $this->getRulesAssoc();
+		if (!isset($aRules['font-size']) || !isset($aRules['font-family'])) {
+			return;
+		}
+		$oNewRule = new Rule('font', $this->iLineNo);
+		foreach (array('font-style', 'font-variant', 'font-weight') as $sProperty) {
+			if (isset($aRules[$sProperty])) {
+				$oRule = $aRules[$sProperty];
+				$mRuleValue = $oRule->getValue();
+				$aValues = array();
+				if (!$mRuleValue instanceof RuleValueList) {
+					$aValues[] = $mRuleValue;
+				} else {
+					$aValues = $mRuleValue->getListComponents();
+				}
+				if ($aValues[0] !== 'normal') {
+					$oNewRule->addValue($aValues[0]);
+				}
+			}
+		}
+		// Get the font-size value
+		$oRule = $aRules['font-size'];
+		$mRuleValue = $oRule->getValue();
+		$aFSValues = array();
+		if (!$mRuleValue instanceof RuleValueList) {
+			$aFSValues[] = $mRuleValue;
+		} else {
+			$aFSValues = $mRuleValue->getListComponents();
+		}
+		// But wait to know if we have line-height to add it
+		if (isset($aRules['line-height'])) {
+			$oRule = $aRules['line-height'];
+			$mRuleValue = $oRule->getValue();
+			$aLHValues = array();
+			if (!$mRuleValue instanceof RuleValueList) {
+				$aLHValues[] = $mRuleValue;
+			} else {
+				$aLHValues = $mRuleValue->getListComponents();
+			}
+			if ($aLHValues[0] !== 'normal') {
+				$val = new RuleValueList('/', $this->iLineNo);
+				$val->addListComponent($aFSValues[0]);
+				$val->addListComponent($aLHValues[0]);
+				$oNewRule->addValue($val);
+			}
+		} else {
+			$oNewRule->addValue($aFSValues[0]);
+		}
+		$oRule = $aRules['font-family'];
+		$mRuleValue = $oRule->getValue();
+		$aFFValues = array();
+		if (!$mRuleValue instanceof RuleValueList) {
+			$aFFValues[] = $mRuleValue;
+		} else {
+			$aFFValues = $mRuleValue->getListComponents();
+		}
+		$oFFValue = new RuleValueList(',', $this->iLineNo);
+		$oFFValue->setListComponents($aFFValues);
+		$oNewRule->addValue($oFFValue);
+
+		$this->addRule($oNewRule);
+		foreach ($aFontProperties as $sProperty) {
+			$this->removeRule($sProperty);
+		}
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		if(count($this->aSelectors) === 0) {
+			// If all the selectors have been removed, this declaration block becomes invalid
+			throw new OutputException("Attempt to print declaration block with missing selector", $this->iLineNo);
+		}
+		$sResult = $oOutputFormat->implode($oOutputFormat->spaceBeforeSelectorSeparator() . ',' . $oOutputFormat->spaceAfterSelectorSeparator(), $this->aSelectors) . $oOutputFormat->spaceBeforeOpeningBrace() . '{';
+		$sResult .= parent::render($oOutputFormat);
+		$sResult .= '}';
+		return $sResult;
+	}
+
+}
diff --git a/lib/php-css-parser/RuleSet/RuleSet.php b/lib/php-css-parser/RuleSet/RuleSet.php
new file mode 100644
index 00000000000..124be88db4a
--- /dev/null
+++ b/lib/php-css-parser/RuleSet/RuleSet.php
@@ -0,0 +1,173 @@
+<?php
+
+namespace Sabberworm\CSS\RuleSet;
+
+use Sabberworm\CSS\Rule\Rule;
+use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\Comment\Commentable;
+
+/**
+ * RuleSet is a generic superclass denoting rules. The typical example for rule sets are declaration block.
+ * However, unknown At-Rules (like @font-face) are also rule sets.
+ */
+abstract class RuleSet implements Renderable, Commentable {
+
+	private $aRules;
+	protected $iLineNo;
+	protected $aComments;
+
+	public function __construct($iLineNo = 0) {
+		$this->aRules = array();
+		$this->iLineNo = $iLineNo;
+		$this->aComments = array();
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	public function addRule(Rule $oRule, Rule $oSibling = null) {
+		$sRule = $oRule->getRule();
+		if(!isset($this->aRules[$sRule])) {
+			$this->aRules[$sRule] = array();
+		}
+
+		$iPosition = count($this->aRules[$sRule]);
+
+		if ($oSibling !== null) {
+			$iSiblingPos = array_search($oSibling, $this->aRules[$sRule], true);
+			if ($iSiblingPos !== false) {
+				$iPosition = $iSiblingPos;
+			}
+		}
+
+		array_splice($this->aRules[$sRule], $iPosition, 0, array($oRule));
+	}
+
+	/**
+	 * Returns all rules matching the given rule name
+	 * @param (null|string|Rule) $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
+	 * @example $oRuleSet->getRules('font-') //returns an array of all rules either beginning with font- or matching font.
+	 * @example $oRuleSet->getRules('font') //returns array(0 => $oRule, …) or array().
+	 */
+	public function getRules($mRule = null) {
+		if ($mRule instanceof Rule) {
+			$mRule = $mRule->getRule();
+		}
+		$aResult = array();
+		foreach($this->aRules as $sName => $aRules) {
+			// Either no search rule is given or the search rule matches the found rule exactly or the search rule ends in “-” and the found rule starts with the search rule.
+			if(!$mRule || $sName === $mRule || (strrpos($mRule, '-') === strlen($mRule) - strlen('-') && (strpos($sName, $mRule) === 0 || $sName === substr($mRule, 0, -1)))) {
+				$aResult = array_merge($aResult, $aRules);
+			}
+		}
+		return $aResult;
+	}
+
+	/**
+	 * Override all the rules of this set.
+	 * @param array $aRules The rules to override with.
+	 */
+	public function setRules(array $aRules) {
+		$this->aRules = array();
+		foreach ($aRules as $rule) {
+			$this->addRule($rule);
+		}
+	}
+
+	/**
+	 * Returns all rules matching the given pattern and returns them in an associative array with the rule’s name as keys. This method exists mainly for backwards-compatibility and is really only partially useful.
+	 * @param (string) $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
+	 * Note: This method loses some information: Calling this (with an argument of 'background-') on a declaration block like { background-color: green; background-color; rgba(0, 127, 0, 0.7); } will only yield an associative array containing the rgba-valued rule while @link{getRules()} would yield an indexed array containing both.
+	 */
+	public function getRulesAssoc($mRule = null) {
+		$aResult = array();
+		foreach($this->getRules($mRule) as $oRule) {
+			$aResult[$oRule->getRule()] = $oRule;
+		}
+		return $aResult;
+	}
+
+	/**
+	* Remove a rule from this RuleSet. This accepts all the possible values that @link{getRules()} accepts. If given a Rule, it will only remove this particular rule (by identity). If given a name, it will remove all rules by that name. Note: this is different from pre-v.2.0 behaviour of PHP-CSS-Parser, where passing a Rule instance would remove all rules with the same name. To get the old behvaiour, use removeRule($oRule->getRule()).
+ * @param (null|string|Rule) $mRule pattern to remove. If $mRule is null, all rules are removed. If the pattern ends in a dash, all rules starting with the pattern are removed as well as one matching the pattern with the dash excluded. Passing a Rule behaves matches by identity.
+	*/
+	public function removeRule($mRule) {
+		if($mRule instanceof Rule) {
+			$sRule = $mRule->getRule();
+			if(!isset($this->aRules[$sRule])) {
+				return;
+			}
+			foreach($this->aRules[$sRule] as $iKey => $oRule) {
+				if($oRule === $mRule) {
+					unset($this->aRules[$sRule][$iKey]);
+				}
+			}
+		} else {
+			foreach($this->aRules as $sName => $aRules) {
+				// Either no search rule is given or the search rule matches the found rule exactly or the search rule ends in “-” and the found rule starts with the search rule or equals it (without the trailing dash).
+				if(!$mRule || $sName === $mRule || (strrpos($mRule, '-') === strlen($mRule) - strlen('-') && (strpos($sName, $mRule) === 0 || $sName === substr($mRule, 0, -1)))) {
+					unset($this->aRules[$sName]);
+				}
+			}
+		}
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sResult = '';
+		$bIsFirst = true;
+		foreach ($this->aRules as $aRules) {
+			foreach($aRules as $oRule) {
+				$sRendered = $oOutputFormat->safely(function() use ($oRule, $oOutputFormat) {
+					return $oRule->render($oOutputFormat->nextLevel());
+				});
+				if($sRendered === null) {
+					continue;
+				}
+				if($bIsFirst) {
+					$bIsFirst = false;
+					$sResult .= $oOutputFormat->nextLevel()->spaceBeforeRules();
+				} else {
+					$sResult .= $oOutputFormat->nextLevel()->spaceBetweenRules();
+				}
+				$sResult .= $sRendered;
+			}
+		}
+		
+		if(!$bIsFirst) {
+			// Had some output
+			$sResult .= $oOutputFormat->spaceAfterRules();
+		}
+
+		return $oOutputFormat->removeLastSemicolon($sResult);
+	}
+
+	/**
+	 * @param array $aComments Array of comments.
+	 */
+	public function addComments(array $aComments) {
+		$this->aComments = array_merge($this->aComments, $aComments);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getComments() {
+		return $this->aComments;
+	}
+
+	/**
+	 * @param array $aComments Array containing Comment objects.
+	 */
+	public function setComments(array $aComments) {
+		$this->aComments = $aComments;
+	}
+
+}
diff --git a/lib/php-css-parser/Settings.php b/lib/php-css-parser/Settings.php
new file mode 100644
index 00000000000..cb89a8636ba
--- /dev/null
+++ b/lib/php-css-parser/Settings.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace Sabberworm\CSS;
+
+use Sabberworm\CSS\Rule\Rule;
+
+/**
+ * Parser settings class.
+ *
+ * Configure parser behaviour here.
+ */
+class Settings {
+	/**
+	* Multi-byte string support. If true (mbstring extension must be enabled), will use (slower) mb_strlen, mb_convert_case, mb_substr and mb_strpos functions. Otherwise, the normal (ASCII-Only) functions will be used.
+	*/
+	public $bMultibyteSupport;
+
+	/**
+	* The default charset for the CSS if no `@charset` rule is found. Defaults to utf-8.
+	*/
+	public $sDefaultCharset = 'utf-8';
+
+	/**
+	* Lenient parsing. When used (which is true by default), the parser will not choke on unexpected tokens but simply ignore them.
+	*/
+	public $bLenientParsing = true;
+
+	private function __construct() {
+		$this->bMultibyteSupport = extension_loaded('mbstring');
+	}
+
+	public static function create() {
+		return new Settings();
+	}
+	
+	public function withMultibyteSupport($bMultibyteSupport = true) {
+		$this->bMultibyteSupport = $bMultibyteSupport;
+		return $this;
+	}
+	
+	public function withDefaultCharset($sDefaultCharset) {
+		$this->sDefaultCharset = $sDefaultCharset;
+		return $this;
+	}
+	
+	public function withLenientParsing($bLenientParsing = true) {
+		$this->bLenientParsing = $bLenientParsing;
+		return $this;
+	}
+	
+	public function beStrict() {
+		return $this->withLenientParsing(false);
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Value/CSSFunction.php b/lib/php-css-parser/Value/CSSFunction.php
new file mode 100644
index 00000000000..3633abc756c
--- /dev/null
+++ b/lib/php-css-parser/Value/CSSFunction.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+class CSSFunction extends ValueList {
+
+	private $sName;
+
+	public function __construct($sName, $aArguments, $sSeparator = ',', $iLineNo = 0) {
+		if($aArguments instanceof RuleValueList) {
+			$sSeparator = $aArguments->getListSeparator();
+			$aArguments = $aArguments->getListComponents();
+		}
+		$this->sName = $sName;
+		$this->iLineNo = $iLineNo;
+		parent::__construct($aArguments, $sSeparator, $iLineNo);
+	}
+
+	public function getName() {
+		return $this->sName;
+	}
+
+	public function setName($sName) {
+		$this->sName = $sName;
+	}
+
+	public function getArguments() {
+		return $this->aComponents;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$aArguments = parent::render($oOutputFormat);
+		return "{$this->sName}({$aArguments})";
+	}
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Value/CSSString.php b/lib/php-css-parser/Value/CSSString.php
new file mode 100644
index 00000000000..b07000818e2
--- /dev/null
+++ b/lib/php-css-parser/Value/CSSString.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+class CSSString extends PrimitiveValue {
+
+	private $sString;
+
+	public function __construct($sString, $iLineNo = 0) {
+		$this->sString = $sString;
+		parent::__construct($iLineNo);
+	}
+
+	public function setString($sString) {
+		$this->sString = $sString;
+	}
+
+	public function getString() {
+		return $this->sString;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$sString = addslashes($this->sString);
+		$sString = str_replace("\n", '\A', $sString);
+		return $oOutputFormat->getStringQuotingType() . $sString . $oOutputFormat->getStringQuotingType();
+	}
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Value/Color.php b/lib/php-css-parser/Value/Color.php
new file mode 100644
index 00000000000..e05b924a678
--- /dev/null
+++ b/lib/php-css-parser/Value/Color.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+class Color extends CSSFunction {
+
+	public function __construct($aColor, $iLineNo = 0) {
+		parent::__construct(implode('', array_keys($aColor)), $aColor, ',', $iLineNo);
+	}
+
+	public function getColor() {
+		return $this->aComponents;
+	}
+
+	public function setColor($aColor) {
+		$this->setName(implode('', array_keys($aColor)));
+		$this->aComponents = $aColor;
+	}
+
+	public function getColorDescription() {
+		return $this->getName();
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		// Shorthand RGB color values
+		if($oOutputFormat->getRGBHashNotation() && implode('', array_keys($this->aComponents)) === 'rgb') {
+			$sResult = sprintf(
+				'%02x%02x%02x',
+				$this->aComponents['r']->getSize(),
+				$this->aComponents['g']->getSize(),
+				$this->aComponents['b']->getSize()
+			);
+			return '#'.(($sResult[0] == $sResult[1]) && ($sResult[2] == $sResult[3]) && ($sResult[4] == $sResult[5]) ? "$sResult[0]$sResult[2]$sResult[4]" : $sResult);
+		}
+		return parent::render($oOutputFormat);
+	}
+}
diff --git a/lib/php-css-parser/Value/PrimitiveValue.php b/lib/php-css-parser/Value/PrimitiveValue.php
new file mode 100644
index 00000000000..187ce7e6a01
--- /dev/null
+++ b/lib/php-css-parser/Value/PrimitiveValue.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+abstract class PrimitiveValue extends Value {
+    public function __construct($iLineNo = 0) {
+        parent::__construct($iLineNo);
+    }
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Value/RuleValueList.php b/lib/php-css-parser/Value/RuleValueList.php
new file mode 100644
index 00000000000..d89c326caf3
--- /dev/null
+++ b/lib/php-css-parser/Value/RuleValueList.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+class RuleValueList extends ValueList {
+	public function __construct($sSeparator = ',', $iLineNo = 0) {
+		parent::__construct(array(), $sSeparator, $iLineNo);
+	}
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Value/Size.php b/lib/php-css-parser/Value/Size.php
new file mode 100644
index 00000000000..9ad5eb086ad
--- /dev/null
+++ b/lib/php-css-parser/Value/Size.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+class Size extends PrimitiveValue {
+
+	const ABSOLUTE_SIZE_UNITS = 'px/cm/mm/mozmm/in/pt/pc/vh/vw/vm/vmin/vmax/rem'; //vh/vw/vm(ax)/vmin/rem are absolute insofar as they don’t scale to the immediate parent (only the viewport)
+	const RELATIVE_SIZE_UNITS = '%/em/ex/ch/fr';
+	const NON_SIZE_UNITS = 'deg/grad/rad/s/ms/turns/Hz/kHz';
+
+	private $fSize;
+	private $sUnit;
+	private $bIsColorComponent;
+
+	public function __construct($fSize, $sUnit = null, $bIsColorComponent = false, $iLineNo = 0) {
+		parent::__construct($iLineNo);
+		$this->fSize = floatval($fSize);
+		$this->sUnit = $sUnit;
+		$this->bIsColorComponent = $bIsColorComponent;
+	}
+
+	public function setUnit($sUnit) {
+		$this->sUnit = $sUnit;
+	}
+
+	public function getUnit() {
+		return $this->sUnit;
+	}
+
+	public function setSize($fSize) {
+		$this->fSize = floatval($fSize);
+	}
+
+	public function getSize() {
+		return $this->fSize;
+	}
+
+	public function isColorComponent() {
+		return $this->bIsColorComponent;
+	}
+
+	/**
+	 * Returns whether the number stored in this Size really represents a size (as in a length of something on screen).
+	 * @return false if the unit an angle, a duration, a frequency or the number is a component in a Color object.
+	 */
+	public function isSize() {
+		if (in_array($this->sUnit, explode('/', self::NON_SIZE_UNITS))) {
+			return false;
+		}
+		return !$this->isColorComponent();
+	}
+
+	public function isRelative() {
+		if (in_array($this->sUnit, explode('/', self::RELATIVE_SIZE_UNITS))) {
+			return true;
+		}
+		if ($this->sUnit === null && $this->fSize != 0) {
+			return true;
+		}
+		return false;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		$l = localeconv();
+		$sPoint = preg_quote($l['decimal_point'], '/');
+		return preg_replace(array("/$sPoint/", "/^(-?)0\./"), array('.', '$1.'), $this->fSize) . ($this->sUnit === null ? '' : $this->sUnit);
+	}
+
+}
diff --git a/lib/php-css-parser/Value/URL.php b/lib/php-css-parser/Value/URL.php
new file mode 100644
index 00000000000..02cf5812db5
--- /dev/null
+++ b/lib/php-css-parser/Value/URL.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+
+class URL extends PrimitiveValue {
+
+	private $oURL;
+
+	public function __construct(CSSString $oURL, $iLineNo = 0) {
+		parent::__construct($iLineNo);
+		$this->oURL = $oURL;
+	}
+
+	public function setURL(CSSString $oURL) {
+		$this->oURL = $oURL;
+	}
+
+	public function getURL() {
+		return $this->oURL;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		return "url({$this->oURL->render($oOutputFormat)})";
+	}
+
+}
\ No newline at end of file
diff --git a/lib/php-css-parser/Value/Value.php b/lib/php-css-parser/Value/Value.php
new file mode 100644
index 00000000000..5d30bd97fb5
--- /dev/null
+++ b/lib/php-css-parser/Value/Value.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+use Sabberworm\CSS\Renderable;
+
+abstract class Value implements Renderable {
+    protected $iLineNo;
+
+    public function __construct($iLineNo = 0) {
+        $this->iLineNo = $iLineNo;
+    }
+    
+    /**
+     * @return int
+     */
+    public function getLineNo() {
+        return $this->iLineNo;
+    }
+
+    //Methods are commented out because re-declaring them here is a fatal error in PHP < 5.3.9
+	//public abstract function __toString();
+	//public abstract function render(\Sabberworm\CSS\OutputFormat $oOutputFormat);
+}
diff --git a/lib/php-css-parser/Value/ValueList.php b/lib/php-css-parser/Value/ValueList.php
new file mode 100644
index 00000000000..5c3d0e4fb0f
--- /dev/null
+++ b/lib/php-css-parser/Value/ValueList.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+abstract class ValueList extends Value {
+
+	protected $aComponents;
+	protected $sSeparator;
+
+	public function __construct($aComponents = array(), $sSeparator = ',', $iLineNo = 0) {
+		parent::__construct($iLineNo);
+		if (!is_array($aComponents)) {
+			$aComponents = array($aComponents);
+		}
+		$this->aComponents = $aComponents;
+		$this->sSeparator = $sSeparator;
+	}
+
+	public function addListComponent($mComponent) {
+		$this->aComponents[] = $mComponent;
+	}
+
+	public function getListComponents() {
+		return $this->aComponents;
+	}
+
+	public function setListComponents($aComponents) {
+		$this->aComponents = $aComponents;
+	}
+
+	public function getListSeparator() {
+		return $this->sSeparator;
+	}
+
+	public function setListSeparator($sSeparator) {
+		$this->sSeparator = $sSeparator;
+	}
+
+	public function __toString() {
+		return $this->render(new \Sabberworm\CSS\OutputFormat());
+	}
+
+	public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
+		return $oOutputFormat->implode($oOutputFormat->spaceBeforeListArgumentSeparator($this->sSeparator) . $this->sSeparator . $oOutputFormat->spaceAfterListArgumentSeparator($this->sSeparator), $this->aComponents);
+	}
+
+}
diff --git a/lib/php-css-parser/moodle_readme.txt b/lib/php-css-parser/moodle_readme.txt
new file mode 100644
index 00000000000..52e303ee5fb
--- /dev/null
+++ b/lib/php-css-parser/moodle_readme.txt
@@ -0,0 +1,11 @@
+PHP CSS Parser
+--------------
+
+Import git ref: 50a802f562e71236140e2a8903b097c28d6101de
+                (master)
+
+Downloaded from: https://github.com/sabberworm/PHP-CSS-Parser
+
+Import procedure:
+
+- Copy all the files from the folder 'lib/Sabberworm/CSS/' in this directory.
diff --git a/lib/thirdpartylibs.xml b/lib/thirdpartylibs.xml
index 25bccc5f42d..61321f68347 100644
--- a/lib/thirdpartylibs.xml
+++ b/lib/thirdpartylibs.xml
@@ -241,6 +241,12 @@
     <license>GPL</license>
     <version>1.6.3</version>
   </library>
+  <library>
+    <location>php-css-parser</location>
+    <name>PHP-CSS-Parser</name>
+    <license>MIT</license>
+    <version>8.1.0</version>
+  </library>
   <library>
     <location>rtlcss</location>
     <name>RTLCSS for PHP</name>