Fix link to CSS declaration blocks (mdn#32924)

files/en-us/web/css/at-rule/index.md

@@ -9,7 +9,7 @@ spec-urls:
 
 {{CSSRef}}
 
-**At-rules** are [CSS statements](/en-US/docs/Web/CSS/Syntax#css_statements) that instruct CSS how to behave. They begin with an at sign, '`@`' (`U+0040 COMMERCIAL AT`), followed by an identifier and includes everything up to the next semicolon, '`;`' (`U+003B SEMICOLON`), or the next [CSS block](/en-US/docs/Web/CSS/Syntax#css_declarations_blocks), whichever comes first.
+**At-rules** are [CSS statements](/en-US/docs/Web/CSS/Syntax#css_statements) that instruct CSS how to behave. They begin with an at sign, '`@`' (`U+0040 COMMERCIAL AT`), followed by an identifier and includes everything up to the next semicolon, '`;`' (`U+003B SEMICOLON`), or the next [CSS block](/en-US/docs/Web/CSS/Syntax#css_declaration_blocks), whichever comes first.
 
 ## Syntax