diff --git a/CHANGELOG.md b/CHANGELOG.md
index 837a3a0f1..dfb61cdf5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,15 @@
+## 1.52.0
+
+* Add support for arbitrary modifiers at the end of plain CSS imports, in
+  addition to the existing `supports()` and media queries. Sass now allows any
+  sequence of identifiers of functions after the URL of an import for forwards
+  compatibility with future additions to the CSS spec.
+
 ## 1.51.1
 
 * Fix an issue where source locations tracked through variable references could
   potentially become incorrect.
+
 * Fix a bug where a loud comment in the source can break the source map when
   embedding the sources, when using the command-line interface or the legacy JS
   API.
diff --git a/lib/src/ast/css/import.dart b/lib/src/ast/css/import.dart
index 33db7c9b9..b8ad9e9e0 100644
--- a/lib/src/ast/css/import.dart
+++ b/lib/src/ast/css/import.dart
@@ -3,7 +3,6 @@
 // https://opensource.org/licenses/MIT.
 
 import '../../visitor/interface/css.dart';
-import 'media_query.dart';
 import 'node.dart';
 import 'value.dart';
 
@@ -14,11 +13,8 @@ abstract class CssImport extends CssNode {
   /// This includes quotes.
   CssValue<String> get url;
 
-  /// The supports condition attached to this import.
-  CssValue<String>? get supports;
-
-  /// The media query attached to this import.
-  List<CssMediaQuery>? get media;
+  /// The modifiers (such as media or supports queries) attached to this import.
+  CssValue<String>? get modifiers;
 
   T accept<T>(CssVisitor<T> visitor) => visitor.visitCssImport(this);
 }
diff --git a/lib/src/ast/css/modifiable/import.dart b/lib/src/ast/css/modifiable/import.dart
index 9d705b72e..033424e78 100644
--- a/lib/src/ast/css/modifiable/import.dart
+++ b/lib/src/ast/css/modifiable/import.dart
@@ -6,7 +6,6 @@ import 'package:source_span/source_span.dart';
 
 import '../../../visitor/interface/modifiable_css.dart';
 import '../import.dart';
-import '../media_query.dart';
 import '../value.dart';
 import 'node.dart';
 
@@ -17,17 +16,11 @@ class ModifiableCssImport extends ModifiableCssNode implements CssImport {
   /// This includes quotes.
   final CssValue<String> url;
 
-  /// The supports condition attached to this import.
-  final CssValue<String>? supports;
-
-  /// The media query attached to this import.
-  final List<CssMediaQuery>? media;
+  final CssValue<String>? modifiers;
 
   final FileSpan span;
 
-  ModifiableCssImport(this.url, this.span,
-      {this.supports, Iterable<CssMediaQuery>? media})
-      : media = media == null ? null : List.unmodifiable(media);
+  ModifiableCssImport(this.url, this.span, {this.modifiers});
 
   T accept<T>(ModifiableCssVisitor<T> visitor) => visitor.visitCssImport(this);
 }
diff --git a/lib/src/ast/sass/import/static.dart b/lib/src/ast/sass/import/static.dart
index 6388a5cbd..69b1e3bb3 100644
--- a/lib/src/ast/sass/import/static.dart
+++ b/lib/src/ast/sass/import/static.dart
@@ -7,7 +7,6 @@ import 'package:source_span/source_span.dart';
 
 import '../import.dart';
 import '../interpolation.dart';
-import '../supports_condition.dart';
 
 /// An import that produces a plain CSS `@import` rule.
 ///
@@ -19,22 +18,13 @@ class StaticImport implements Import {
   /// This already contains quotes.
   final Interpolation url;
 
-  /// The supports condition attached to this import, or `null` if no condition
-  /// is attached.
-  final SupportsCondition? supports;
-
-  /// The media query attached to this import, or `null` if no condition is
-  /// attached.
-  final Interpolation? media;
+  /// The modifiers (such as media or supports queries) attached to this import,
+  /// or `null` if none are attached.
+  final Interpolation? modifiers;
 
   final FileSpan span;
 
-  StaticImport(this.url, this.span, {this.supports, this.media});
+  StaticImport(this.url, this.span, {this.modifiers});
 
-  String toString() {
-    var buffer = StringBuffer(url);
-    if (supports != null) buffer.write(" supports($supports)");
-    if (media != null) buffer.write(" $media");
-    return buffer.toString();
-  }
+  String toString() => "$url${modifiers == null ? '' : ' $modifiers'}";
 }
diff --git a/lib/src/ast/sass/interpolation.dart b/lib/src/ast/sass/interpolation.dart
index dd3698348..17a440666 100644
--- a/lib/src/ast/sass/interpolation.dart
+++ b/lib/src/ast/sass/interpolation.dart
@@ -5,6 +5,7 @@
 import 'package:meta/meta.dart';
 import 'package:source_span/source_span.dart';
 
+import '../../interpolation_buffer.dart';
 import 'expression.dart';
 import 'node.dart';
 
@@ -40,6 +41,32 @@ class Interpolation implements SassNode {
     return first is String ? first : '';
   }
 
+  /// Creates a new [Interpolation] by concatenating a sequence of [String]s,
+  /// [Expression]s, or nested [Interpolation]s.
+  static Interpolation concat(
+      Iterable<Object /* String | Expression | Interpolation */ > contents,
+      FileSpan span) {
+    var buffer = InterpolationBuffer();
+    for (var element in contents) {
+      if (element is! String &&
+          element is! Expression &&
+          element is! Interpolation) {
+        throw ArgumentError.value(contents, "contents",
+            "May only contains Strings, Expressions, or Interpolations.");
+      }
+
+      if (element is String) {
+        buffer.write(element);
+      } else if (element is Expression) {
+        buffer.add(element);
+      } else if (element is Interpolation) {
+        buffer.addInterpolation(element);
+      }
+    }
+
+    return buffer.interpolation(span);
+  }
+
   Interpolation(Iterable<Object /* String | Expression */ > contents, this.span)
       : contents = List.unmodifiable(contents) {
     for (var i = 0; i < this.contents.length; i++) {
diff --git a/lib/src/ast/sass/supports_condition.dart b/lib/src/ast/sass/supports_condition.dart
index 53f96bb38..112ca9a30 100644
--- a/lib/src/ast/sass/supports_condition.dart
+++ b/lib/src/ast/sass/supports_condition.dart
@@ -4,10 +4,15 @@
 
 import 'package:meta/meta.dart';
 
+import 'interpolation.dart';
 import 'node.dart';
 
 /// An abstract class for defining the condition a `@supports` rule selects.
 ///
 /// {@category AST}
 @sealed
-abstract class SupportsCondition extends SassNode {}
+abstract class SupportsCondition extends SassNode {
+  /// Returns an [Interpolation] that evaluates to the same value as this
+  /// [SupportsCondition].
+  Interpolation toInterpolation();
+}
diff --git a/lib/src/ast/sass/supports_condition/anything.dart b/lib/src/ast/sass/supports_condition/anything.dart
index 4dbece4b2..48208619d 100644
--- a/lib/src/ast/sass/supports_condition/anything.dart
+++ b/lib/src/ast/sass/supports_condition/anything.dart
@@ -21,5 +21,8 @@ class SupportsAnything implements SupportsCondition {
 
   SupportsAnything(this.contents, this.span);
 
+  Interpolation toInterpolation() =>
+      Interpolation.concat(['(', contents, ')'], span);
+
   String toString() => "($contents)";
 }
diff --git a/lib/src/ast/sass/supports_condition/declaration.dart b/lib/src/ast/sass/supports_condition/declaration.dart
index d29d717c9..c60a28bad 100644
--- a/lib/src/ast/sass/supports_condition/declaration.dart
+++ b/lib/src/ast/sass/supports_condition/declaration.dart
@@ -7,6 +7,7 @@ import 'package:source_span/source_span.dart';
 
 import '../expression.dart';
 import '../expression/string.dart';
+import '../interpolation.dart';
 import '../supports_condition.dart';
 
 /// A condition that selects for browsers where a given declaration is
@@ -42,5 +43,8 @@ class SupportsDeclaration implements SupportsCondition {
 
   SupportsDeclaration(this.name, this.value, this.span);
 
+  Interpolation toInterpolation() => Interpolation.concat(
+      ['(', name, isCustomProperty ? ':' : ': ', value, ')'], span);
+
   String toString() => "($name: $value)";
 }
diff --git a/lib/src/ast/sass/supports_condition/function.dart b/lib/src/ast/sass/supports_condition/function.dart
index 73bdb9bda..1c239c9dc 100644
--- a/lib/src/ast/sass/supports_condition/function.dart
+++ b/lib/src/ast/sass/supports_condition/function.dart
@@ -23,5 +23,8 @@ class SupportsFunction implements SupportsCondition {
 
   SupportsFunction(this.name, this.arguments, this.span);
 
+  Interpolation toInterpolation() =>
+      Interpolation.concat([name, '(', arguments, ')'], span);
+
   String toString() => "$name($arguments)";
 }
diff --git a/lib/src/ast/sass/supports_condition/interpolation.dart b/lib/src/ast/sass/supports_condition/interpolation.dart
index 9fbd85829..9f0e3a5aa 100644
--- a/lib/src/ast/sass/supports_condition/interpolation.dart
+++ b/lib/src/ast/sass/supports_condition/interpolation.dart
@@ -6,6 +6,7 @@ import 'package:meta/meta.dart';
 import 'package:source_span/source_span.dart';
 
 import '../expression.dart';
+import '../interpolation.dart';
 import '../supports_condition.dart';
 
 /// An interpolated condition.
@@ -20,5 +21,7 @@ class SupportsInterpolation implements SupportsCondition {
 
   SupportsInterpolation(this.expression, this.span);
 
+  Interpolation toInterpolation() => Interpolation([expression], span);
+
   String toString() => "#{$expression}";
 }
diff --git a/lib/src/ast/sass/supports_condition/negation.dart b/lib/src/ast/sass/supports_condition/negation.dart
index 4187f3793..5550a0446 100644
--- a/lib/src/ast/sass/supports_condition/negation.dart
+++ b/lib/src/ast/sass/supports_condition/negation.dart
@@ -5,6 +5,7 @@
 import 'package:meta/meta.dart';
 import 'package:source_span/source_span.dart';
 
+import '../interpolation.dart';
 import '../supports_condition.dart';
 import 'operation.dart';
 
@@ -20,6 +21,17 @@ class SupportsNegation implements SupportsCondition {
 
   SupportsNegation(this.condition, this.span);
 
+  Interpolation toInterpolation() {
+    var needsParens =
+        condition is SupportsNegation || condition is SupportsOperation;
+    return Interpolation.concat([
+      "not ",
+      if (needsParens) "(",
+      condition.toInterpolation(),
+      if (needsParens) ")"
+    ], span);
+  }
+
   String toString() {
     if (condition is SupportsNegation || condition is SupportsOperation) {
       return "not ($condition)";
diff --git a/lib/src/ast/sass/supports_condition/operation.dart b/lib/src/ast/sass/supports_condition/operation.dart
index 3e4fc5113..13249dbad 100644
--- a/lib/src/ast/sass/supports_condition/operation.dart
+++ b/lib/src/ast/sass/supports_condition/operation.dart
@@ -5,6 +5,7 @@
 import 'package:meta/meta.dart';
 import 'package:source_span/source_span.dart';
 
+import '../interpolation.dart';
 import '../supports_condition.dart';
 import 'negation.dart';
 
@@ -34,10 +35,25 @@ class SupportsOperation implements SupportsCondition {
     }
   }
 
+  Interpolation toInterpolation() => Interpolation.concat([
+        ..._parenthesizeInterpolation(left),
+        " $operator ",
+        ..._parenthesizeInterpolation(right)
+      ], span);
+
+  /// Returns a list that can be passed to [Interpolation.concat], with
+  /// parentheses around [condition] if necessary.
+  List<Object /* String | Expression | Interpolation */ >
+      _parenthesizeInterpolation(SupportsCondition condition) => condition
+                  is SupportsNegation ||
+              (condition is SupportsOperation && condition.operator == operator)
+          ? ["(", condition.toInterpolation(), ")"]
+          : [condition.toInterpolation()];
+
   String toString() =>
-      "${_parenthesize(left)} $operator ${_parenthesize(right)}";
+      "${_parenthesizeString(left)} $operator ${_parenthesizeString(right)}";
 
-  String _parenthesize(SupportsCondition condition) =>
+  String _parenthesizeString(SupportsCondition condition) =>
       condition is SupportsNegation ||
               (condition is SupportsOperation && condition.operator == operator)
           ? "($condition)"
diff --git a/lib/src/parse/css.dart b/lib/src/parse/css.dart
index ba09278e9..bffdaa7c9 100644
--- a/lib/src/parse/css.dart
+++ b/lib/src/parse/css.dart
@@ -94,11 +94,11 @@ class CssParser extends ScssParser {
     var urlSpan = scanner.spanFrom(urlStart);
 
     whitespace();
-    var queries = tryImportQueries();
+    var modifiers = tryImportModifiers();
     expectStatementSeparator("@import rule");
     return ImportRule([
       StaticImport(Interpolation([url], urlSpan), scanner.spanFrom(urlStart),
-          supports: queries?.item1, media: queries?.item2)
+          modifiers: modifiers)
     ], scanner.spanFrom(start));
   }
 
diff --git a/lib/src/parse/stylesheet.dart b/lib/src/parse/stylesheet.dart
index f106fc033..fd3a3095b 100644
--- a/lib/src/parse/stylesheet.dart
+++ b/lib/src/parse/stylesheet.dart
@@ -1086,20 +1086,20 @@ abstract class StylesheetParser extends Parser {
     if (next == $u || next == $U) {
       var url = dynamicUrl();
       whitespace();
-      var queries = tryImportQueries();
+      var modifiers = tryImportModifiers();
       return StaticImport(Interpolation([url], scanner.spanFrom(start)),
           scanner.spanFrom(start),
-          supports: queries?.item1, media: queries?.item2);
+          modifiers: modifiers);
     }
 
     var url = string();
     var urlSpan = scanner.spanFrom(start);
     whitespace();
-    var queries = tryImportQueries();
-    if (isPlainImportUrl(url) || queries != null) {
+    var modifiers = tryImportModifiers();
+    if (isPlainImportUrl(url) || modifiers != null) {
       return StaticImport(
           Interpolation([urlSpan.text], urlSpan), scanner.spanFrom(start),
-          supports: queries?.item1, media: queries?.item2);
+          modifiers: modifiers);
     } else {
       try {
         return DynamicImport(parseImportUrl(url), urlSpan);
@@ -1135,54 +1135,100 @@ abstract class StylesheetParser extends Parser {
     return url.startsWith("http://") || url.startsWith("https://");
   }
 
-  /// Consumes a supports condition and/or a media query after an `@import`.
+  /// Consumes a sequence of modifiers (such as media or supports queries)
+  /// after an import argument.
   ///
-  /// Returns `null` if neither type of query can be found.
-  Tuple2<SupportsCondition?, Interpolation?>? tryImportQueries() {
-    SupportsCondition? supports;
-    if (scanIdentifier("supports")) {
-      scanner.expectChar($lparen);
-      var start = scanner.state;
-      if (scanIdentifier("not")) {
-        whitespace();
-        supports = SupportsNegation(
-            _supportsConditionInParens(), scanner.spanFrom(start));
-      } else if (scanner.peekChar() == $lparen) {
-        supports = _supportsCondition();
-      } else {
-        if (_lookingAtInterpolatedIdentifier()) {
-          var identifier = interpolatedIdentifier();
-          if (identifier.asPlain?.toLowerCase() == "not") {
-            error('"not" is not a valid identifier here.', identifier.span);
-          }
+  /// Returns `null` if there are no modifiers.
+  Interpolation? tryImportModifiers() {
+    // Exit before allocating anything if we're not looking at any modifiers, as
+    // is the most common case.
+    if (!_lookingAtInterpolatedIdentifier() && scanner.peekChar() != $lparen) {
+      return null;
+    }
 
-          if (scanner.scanChar($lparen)) {
-            var arguments = _interpolatedDeclarationValue(
-                allowEmpty: true, allowSemicolon: true);
-            scanner.expectChar($rparen);
-            supports = SupportsFunction(
-                identifier, arguments, scanner.spanFrom(start));
+    var start = scanner.state;
+    var buffer = InterpolationBuffer();
+    while (true) {
+      if (_lookingAtInterpolatedIdentifier()) {
+        if (!buffer.isEmpty) buffer.writeCharCode($space);
+
+        var identifier = interpolatedIdentifier();
+        buffer.addInterpolation(identifier);
+
+        var name = identifier.asPlain?.toLowerCase();
+        if (name != "and" && scanner.scanChar($lparen)) {
+          if (name == "supports") {
+            var query = _importSupportsQuery();
+            if (query is! SupportsDeclaration) buffer.writeCharCode($lparen);
+            buffer.addInterpolation(query.toInterpolation());
+            if (query is! SupportsDeclaration) buffer.writeCharCode($rparen);
           } else {
-            // Backtrack to parse a variable declaration
-            scanner.state = start;
+            buffer.writeCharCode($lparen);
+            buffer.addInterpolation(_interpolatedDeclarationValue(
+                allowEmpty: true, allowSemicolon: true));
+            buffer.writeCharCode($rparen);
+          }
+
+          scanner.expectChar($rparen);
+          whitespace();
+        } else {
+          whitespace();
+          if (scanner.scanChar($comma)) {
+            buffer.write(", ");
+            buffer.addInterpolation(_mediaQueryList());
+            return buffer.interpolation(scanner.spanFrom(start));
           }
         }
-        if (supports == null) {
-          var name = expression();
-          scanner.expectChar($colon);
-          supports = _supportsDeclarationValue(name, start);
-        }
+      } else if (scanner.peekChar() == $lparen) {
+        if (!buffer.isEmpty) buffer.writeCharCode($space);
+        buffer.addInterpolation(_mediaQueryList());
+        return buffer.interpolation(scanner.spanFrom(start));
+      } else {
+        return buffer.interpolation(scanner.spanFrom(start));
       }
-      scanner.expectChar($rparen);
+    }
+  }
+
+  /// Consumes the contents of a `supports()` function after an `@import` rule
+  /// (but not the function name or parentheses).
+  SupportsCondition _importSupportsQuery() {
+    if (scanIdentifier("not")) {
       whitespace();
+      var start = scanner.state;
+      return SupportsNegation(
+          _supportsConditionInParens(), scanner.spanFrom(start));
+    } else if (scanner.peekChar() == $lparen) {
+      return _supportsCondition();
+    } else {
+      var function = _tryImportSupportsFunction();
+      if (function != null) return function;
+
+      var start = scanner.state;
+      var name = expression();
+      scanner.expectChar($colon);
+      return _supportsDeclarationValue(name, start);
+    }
+  }
+
+  /// Consumes a function call within a `supports()` function after an
+  /// `@import` if available.
+  SupportsFunction? _tryImportSupportsFunction() {
+    if (!_lookingAtInterpolatedIdentifier()) return null;
+
+    var start = scanner.state;
+    var name = interpolatedIdentifier();
+    assert(name.asPlain != "not");
+
+    if (!scanner.scanChar($lparen)) {
+      scanner.state = start;
+      return null;
     }
 
-    var media =
-        _lookingAtInterpolatedIdentifier() || scanner.peekChar() == $lparen
-            ? _mediaQueryList()
-            : null;
-    if (supports == null && media == null) return null;
-    return Tuple2(supports, media);
+    var value =
+        _interpolatedDeclarationValue(allowEmpty: true, allowSemicolon: true);
+    scanner.expectChar($rparen);
+
+    return SupportsFunction(name, value, scanner.spanFrom(start));
   }
 
   /// Consumes an `@include` rule.
diff --git a/lib/src/visitor/async_evaluate.dart b/lib/src/visitor/async_evaluate.dart
index df184909a..9c0e7aad0 100644
--- a/lib/src/visitor/async_evaluate.dart
+++ b/lib/src/visitor/async_evaluate.dart
@@ -1663,20 +1663,10 @@ class _EvaluateVisitor
     // NOTE: this logic is largely duplicated in [visitCssImport]. Most changes
     // here should be mirrored there.
 
-    var url = await _interpolationToValue(import.url);
-    var supports = await import.supports.andThen((supports) async {
-      var arg = supports is SupportsDeclaration
-          ? "${await _evaluateToCss(supports.name)}:"
-              "${supports.isCustomProperty ? '' : ' '}"
-              "${await _evaluateToCss(supports.value)}"
-          : await supports.andThen(_visitSupportsCondition);
-      return CssValue("supports($arg)", supports.span);
-    });
-    var rawMedia = import.media;
-    var mediaQuery = await rawMedia.andThen(_visitMediaQueries);
-
-    var node = ModifiableCssImport(url, import.span,
-        supports: supports, media: mediaQuery);
+    var node = ModifiableCssImport(
+        await _interpolationToValue(import.url), import.span,
+        modifiers: await import.modifiers
+            .andThen<Future<CssValue<String>>?>(_interpolationToValue));
 
     if (_parent != _root) {
       _parent.addChild(node);
@@ -2923,8 +2913,8 @@ class _EvaluateVisitor
     // NOTE: this logic is largely duplicated in [_visitStaticImport]. Most
     // changes here should be mirrored there.
 
-    var modifiableNode = ModifiableCssImport(node.url, node.span,
-        supports: node.supports, media: node.media);
+    var modifiableNode =
+        ModifiableCssImport(node.url, node.span, modifiers: node.modifiers);
     if (_parent != _root) {
       _parent.addChild(modifiableNode);
     } else if (_endOfImports == _root.children.length) {
diff --git a/lib/src/visitor/clone_css.dart b/lib/src/visitor/clone_css.dart
index ba4bf7333..73b0f8b76 100644
--- a/lib/src/visitor/clone_css.dart
+++ b/lib/src/visitor/clone_css.dart
@@ -48,8 +48,7 @@ class _CloneCssVisitor implements CssVisitor<ModifiableCssNode> {
           valueSpanForMap: node.valueSpanForMap);
 
   ModifiableCssImport visitCssImport(CssImport node) =>
-      ModifiableCssImport(node.url, node.span,
-          supports: node.supports, media: node.media);
+      ModifiableCssImport(node.url, node.span, modifiers: node.modifiers);
 
   ModifiableCssKeyframeBlock visitCssKeyframeBlock(CssKeyframeBlock node) =>
       _visitChildren(
diff --git a/lib/src/visitor/evaluate.dart b/lib/src/visitor/evaluate.dart
index 18663b7e4..a89b9a7f1 100644
--- a/lib/src/visitor/evaluate.dart
+++ b/lib/src/visitor/evaluate.dart
@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_evaluate.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: 45277707f5ab21408f3abb8f249ed7115e0a3c0f
+// Checksum: 68136a98fc33b94bd58d0658e325cf90bdfba006
 //
 // ignore_for_file: unused_import
 
@@ -1660,20 +1660,10 @@ class _EvaluateVisitor
     // NOTE: this logic is largely duplicated in [visitCssImport]. Most changes
     // here should be mirrored there.
 
-    var url = _interpolationToValue(import.url);
-    var supports = import.supports.andThen((supports) {
-      var arg = supports is SupportsDeclaration
-          ? "${_evaluateToCss(supports.name)}:"
-              "${supports.isCustomProperty ? '' : ' '}"
-              "${_evaluateToCss(supports.value)}"
-          : supports.andThen(_visitSupportsCondition);
-      return CssValue("supports($arg)", supports.span);
-    });
-    var rawMedia = import.media;
-    var mediaQuery = rawMedia.andThen(_visitMediaQueries);
-
-    var node = ModifiableCssImport(url, import.span,
-        supports: supports, media: mediaQuery);
+    var node = ModifiableCssImport(
+        _interpolationToValue(import.url), import.span,
+        modifiers:
+            import.modifiers.andThen<CssValue<String>?>(_interpolationToValue));
 
     if (_parent != _root) {
       _parent.addChild(node);
@@ -2903,8 +2893,8 @@ class _EvaluateVisitor
     // NOTE: this logic is largely duplicated in [_visitStaticImport]. Most
     // changes here should be mirrored there.
 
-    var modifiableNode = ModifiableCssImport(node.url, node.span,
-        supports: node.supports, media: node.media);
+    var modifiableNode =
+        ModifiableCssImport(node.url, node.span, modifiers: node.modifiers);
     if (_parent != _root) {
       _parent.addChild(modifiableNode);
     } else if (_endOfImports == _root.children.length) {
diff --git a/lib/src/visitor/recursive_ast.dart b/lib/src/visitor/recursive_ast.dart
index 21e37ee61..fbc8589b5 100644
--- a/lib/src/visitor/recursive_ast.dart
+++ b/lib/src/visitor/recursive_ast.dart
@@ -93,8 +93,7 @@ abstract class RecursiveAstVisitor extends RecursiveStatementVisitor
     for (var import in node.imports) {
       if (import is StaticImport) {
         visitInterpolation(import.url);
-        import.supports.andThen(visitSupportsCondition);
-        import.media.andThen(visitInterpolation);
+        import.modifiers.andThen(visitInterpolation);
       }
     }
   }
diff --git a/lib/src/visitor/serialize.dart b/lib/src/visitor/serialize.dart
index 669c624b0..1f1c0c9ec 100644
--- a/lib/src/visitor/serialize.dart
+++ b/lib/src/visitor/serialize.dart
@@ -237,16 +237,10 @@ class _SerializeVisitor
       _writeOptionalSpace();
       _for(node.url, () => _writeImportUrl(node.url.value));
 
-      var supports = node.supports;
-      if (supports != null) {
+      var modifiers = node.modifiers;
+      if (modifiers != null) {
         _writeOptionalSpace();
-        _write(supports);
-      }
-
-      var media = node.media;
-      if (media != null) {
-        _writeOptionalSpace();
-        _writeBetween(media, _commaSeparator, _visitMediaQuery);
+        _buffer.write(modifiers);
       }
     });
   }
diff --git a/pkg/sass_api/CHANGELOG.md b/pkg/sass_api/CHANGELOG.md
index a602c9374..27195ac04 100644
--- a/pkg/sass_api/CHANGELOG.md
+++ b/pkg/sass_api/CHANGELOG.md
@@ -1,3 +1,10 @@
+## 1.0.0-beta.45
+
+* **Breaking change:** Replace `StaticImport.supports` and `StaticImport.media`
+  with a unified `StaticImport.modifiers` field. Same for `CssImport`.
+
+* Add `SupportsCondition.toInterpolation()`.
+
 ## 1.0.0-beta.44
 
 * No user-visible changes.
diff --git a/pkg/sass_api/pubspec.yaml b/pkg/sass_api/pubspec.yaml
index 697d971db..e7e03f8d8 100644
--- a/pkg/sass_api/pubspec.yaml
+++ b/pkg/sass_api/pubspec.yaml
@@ -2,7 +2,7 @@ name: sass_api
 # Note: Every time we add a new Sass AST node, we need to bump the *major*
 # version because it's a breaking change for anyone who's implementing the
 # visitor interface(s).
-version: 1.0.0-beta.44
+version: 1.0.0-beta.45
 description: Additional APIs for Dart Sass.
 homepage: https://github.com/sass/dart-sass
 
@@ -10,7 +10,7 @@ environment:
   sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
-  sass: 1.51.1
+  sass: 1.52.0
 
 dependency_overrides:
   sass: {path: ../..}
diff --git a/pubspec.yaml b/pubspec.yaml
index acd9134be..51c86bf5e 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: sass
-version: 1.51.1-dev
+version: 1.52.0
 description: A Sass implementation in Dart.
 homepage: https://github.com/sass/dart-sass