feat(css): allow scss declarations in @page blocks

crates/biome_css_formatter/src/css/any/page_at_rule_item.rs

@@ -13,6 +13,8 @@ impl FormatRule<AnyCssPageAtRuleItem> for FormatAnyCssPageAtRuleItem {
             AnyCssPageAtRuleItem::CssDeclarationWithSemicolon(node) => node.format().fmt(f),
             AnyCssPageAtRuleItem::CssEmptyDeclaration(node) => node.format().fmt(f),
             AnyCssPageAtRuleItem::CssMarginAtRule(node) => node.format().fmt(f),
+            AnyCssPageAtRuleItem::ScssDeclaration(node) => node.format().fmt(f),
+            AnyCssPageAtRuleItem::ScssNestingDeclaration(node) => node.format().fmt(f),
         }
     }
 }

crates/biome_css_formatter/tests/specs/css/scss/declaration/page-at-rule.scss

@@ -0,0 +1,13 @@
+@page   :left{
+$padding:12px !default;
+padding:$padding;
+
+font:{
+size:12px;
+}
+
+@top-left{
+$margin:4px !global;
+margin:$margin;
+}
+}

crates/biome_css_formatter/tests/specs/css/scss/declaration/page-at-rule.scss.snap

@@ -0,0 +1,56 @@
+---
+source: crates/biome_formatter_test/src/snapshot_builder.rs
+info: css/scss/declaration/page-at-rule.scss
+---
+
+# Input
+
+```scss
+@page   :left{
+$padding:12px !default;
+padding:$padding;
+
+font:{
+size:12px;
+}
+
+@top-left{
+$margin:4px !global;
+margin:$margin;
+}
+}
+
+```
+
+
+=============================
+
+# Outputs
+
+## Output 1
+
+-----
+Indent style: Tab
+Indent width: 2
+Line ending: LF
+Line width: 80
+Quote style: Double Quotes
+Trailing newline: true
+-----
+
+```scss
+@page :left {
+	$padding: 12px !default;
+	padding: $padding;
+
+	font: {
+		size: 12px;
+	}
+
+	@top-left {
+		$margin: 4px !global;
+		margin: $margin;
+	}
+}
+
+```

crates/biome_css_parser/src/syntax/at_rule/page.rs

@@ -5,13 +5,16 @@ use crate::syntax::at_rule::parse_error::{
 };
 use crate::syntax::at_rule::{is_at_at_rule, parse_at_rule};
 use crate::syntax::block::{ParseBlockBody, parse_declaration_or_at_rule_list_block};
+use crate::syntax::parse_error::scss_only_syntax_error;
+use crate::syntax::scss::{is_at_scss_nesting_declaration, parse_scss_nesting_declaration};
 use crate::syntax::{
-    is_at_any_declaration_with_semicolon, is_at_identifier, is_at_qualified_rule,
-    parse_any_declaration_with_semicolon, parse_custom_identifier_with_keywords,
-    parse_qualified_rule, parse_regular_identifier,
+    CssSyntaxFeatures, is_at_any_declaration_with_semicolon, is_at_identifier,
+    is_at_qualified_rule, parse_any_declaration_with_semicolon,
+    parse_custom_identifier_with_keywords, parse_qualified_rule, parse_regular_identifier,
 };
 use biome_css_syntax::CssSyntaxKind::*;
 use biome_css_syntax::{CssSyntaxKind, T};
+use biome_parser::SyntaxFeature;
 use biome_parser::parse_lists::{ParseNodeList, ParseSeparatedList};
 use biome_parser::parse_recovery::{ParseRecoveryTokenSet, RecoveryResult};
 use biome_parser::parsed_syntax::ParsedSyntax::Present;
@@ -169,6 +172,7 @@ impl ParseBlockBody for PageBlock {
     fn is_at_element(&self, p: &mut CssParser) -> bool {
         at_margin_rule(p)
             || is_at_at_rule(p)
+            || is_at_scss_nesting_declaration(p)
             || is_at_any_declaration_with_semicolon(p)
             || is_at_qualified_rule(p)
     }
@@ -192,6 +196,12 @@ impl ParseNodeList for PageAtRuleItemList {
             parse_margin_at_rule(p)
         } else if is_at_at_rule(p) {
             parse_at_rule(p)
+        } else if is_at_scss_nesting_declaration(p) {
+            CssSyntaxFeatures::Scss.parse_exclusive_syntax(
+                p,
+                parse_scss_nesting_declaration,
+                |p, marker| scss_only_syntax_error(p, "SCSS nesting declarations", marker.range(p)),
+            )
         } else if is_at_any_declaration_with_semicolon(p) {
             parse_any_declaration_with_semicolon(p)
         } else if is_at_qualified_rule(p) {

crates/biome_css_parser/tests/css_test_suite/error/at_rule/at_rule_page_error.css.snap

@@ -1,5 +1,6 @@
 ---
 source: crates/biome_css_parser/tests/spec_test.rs
+assertion_line: 208
 expression: snapshot
 ---
 

crates/biome_css_parser/tests/css_test_suite/ok/scss/at-rule/page.scss

@@ -0,0 +1,13 @@
+@page :left {
+  $padding: 12px !default;
+  padding: $padding;
+
+  font: {
+    size: 12px;
+  }
+
+  @top-left {
+    $margin: 4px !global;
+    margin: $margin;
+  }
+}