# Empty stylesheets

/* Just a comment */

==>

StyleSheet(Comment)

# Import statements

@import url("fineprint.css") print;
@import url("bluish.css") speech;
@import 'custom.css';
@import url("chrome://communicator/skin/");
@import "common.css" screen;

==>

StyleSheet(
  ImportStatement(import,CallLiteral(CallTag,StringLiteral),KeywordQuery),
  ImportStatement(import,CallLiteral(CallTag,StringLiteral),KeywordQuery),
  ImportStatement(import,StringLiteral),
  ImportStatement(import,CallLiteral(CallTag,StringLiteral)),
  ImportStatement(import,StringLiteral,KeywordQuery))

# Namespace statements

/* Default namespace */
@namespace url(XML-namespace-URL);
@namespace "XML-namespace-URL";
@namespace url(http://www.w3.org/1999/xhtml);
@namespace svg url(http://www.w3.org/2000/svg);

/* Prefixed namespace */
@namespace prefix url(XML-namespace-URL);
@namespace prefix "XML-namespace-URL";

==>

StyleSheet(
  Comment,
  NamespaceStatement(namespace,CallLiteral(CallTag,ParenthesizedContent)),
  NamespaceStatement(namespace,StringLiteral),
  NamespaceStatement(namespace,CallLiteral(CallTag,ParenthesizedContent)),
  NamespaceStatement(namespace,NamespaceName,CallLiteral(CallTag,ParenthesizedContent)),
  Comment,
  NamespaceStatement(namespace,NamespaceName,CallLiteral(CallTag,ParenthesizedContent)),
  NamespaceStatement(namespace,NamespaceName,StringLiteral))

# Keyframes statements

@keyframes important1 {
  from { margin-top: 50px; }
  50%  { margin-top: 150px !important; } /* ignored */
  to   { margin-top: 100px; }
}

==>

StyleSheet(KeyframesStatement(keyframes,KeyframeName,KeyframeList(
  Keyword,Block(Declaration(PropertyName,NumberLiteral(Unit))),
  NumberLiteral(Unit),Block(Declaration(PropertyName,NumberLiteral(Unit),Important)),
  Comment,
  Keyword,Block(Declaration(PropertyName,NumberLiteral(Unit))))))

# Media statements

@media screen and (min-width: 30em) and (orientation: landscape) {}
@media (min-height: 680px), screen and (orientation: portrait) {}
@media not all and (monochrome) {}
@media only screen {}

==>

StyleSheet(
  MediaStatement(media,BinaryQuery(BinaryQuery(KeywordQuery,LogicOp,FeatureQuery(FeatureName,NumberLiteral(Unit))),LogicOp,
    FeatureQuery(FeatureName,ValueName)),Block),
  MediaStatement(media,FeatureQuery(FeatureName,NumberLiteral(Unit)),BinaryQuery(KeywordQuery,LogicOp,FeatureQuery(FeatureName,ValueName)),Block),
  MediaStatement(media,UnaryQuery(LogicOp,BinaryQuery(KeywordQuery,LogicOp,ParenthesizedQuery(KeywordQuery))),Block),
  MediaStatement(media,UnaryQuery(LogicOp,KeywordQuery),Block))

# Supports statements

@supports (animation-name: test) {
  div { animation-name: test; }
}
@supports (transform-style: preserve) or (-moz-transform-style: preserve) {}
@supports not ((text-align-last: justify) or (-moz-text-align-last: justify)) {}
@supports not selector(:matches(a, b)) {}

==>

StyleSheet(
  SupportsStatement(supports,FeatureQuery(FeatureName,ValueName),Block(RuleSet(TagSelector(TagName),Block(Declaration(PropertyName,ValueName))))),
  SupportsStatement(supports,BinaryQuery(FeatureQuery(FeatureName,ValueName),LogicOp,FeatureQuery(FeatureName,ValueName)),Block),
  SupportsStatement(supports,UnaryQuery(LogicOp,ParenthesizedQuery(
    BinaryQuery(FeatureQuery(FeatureName,ValueName),LogicOp,FeatureQuery(FeatureName,ValueName)))),Block),
  SupportsStatement(supports,UnaryQuery(LogicOp,SelectorQuery(selector,PseudoClassSelector(":",PseudoClassName,ArgList(TagSelector(TagName),TagSelector(TagName))))),Block))

# Charset statements

@charset "utf-8";

==>

StyleSheet(CharsetStatement(charset,StringLiteral))

# Other at-statements

@font-face {
  font-family: "Open Sans";
  src: url("/a") format("woff2"), url("/b/c") format("woff");
}

==>

StyleSheet(AtRule(AtKeyword,Block(
  Declaration(PropertyName,StringLiteral),
  Declaration(PropertyName,CallLiteral(CallTag,StringLiteral),CallExpression(Callee,ArgList(StringLiteral)),
    CallLiteral(CallTag,StringLiteral),CallExpression(Callee,ArgList(StringLiteral))))))