Update src/compiler/compile/css/Selector.ts

Co-authored-by: Yuichiro Yamashita <xydybaseball@gmail.com>

src/compiler/compile/css/Selector.ts

@@ -350,7 +350,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 	const attr = node.attributes.find((attr: CssNode) => attr.name === name);
 	if (!attr) return false;
 	if (attr.is_true) return operator === null;
-	if (expected_value === null) return true;
+	if (expected_value == null) return true;
 
 	if (attr.chunks.length === 1) {
 		const value = attr.chunks[0];