diff --git a/lib/vast/Parser.py b/lib/vast/Parser.py
index 507366a..e11f83c 100644
--- a/lib/vast/Parser.py
+++ b/lib/vast/Parser.py
@@ -883,8 +883,12 @@ class Parser(ExprParserMixin):
                     value={'True': True, 'False': False, 'None': None}[tok.Value])
                 self._FixLoc(node, tok)
                 return node
-            # 类模式：Name(...) 或 a.b(...)
-            if self._Peek(1).Type == OP and self._Peek(1).Value == '(':
+            # 类模式：Name(...) 或 a.b.c(...)——扫描属性链末尾判断 '('
+            peek_i: int = 1
+            while (self._Peek(peek_i).Type == OP and self._Peek(peek_i).Value == '.'
+                   and self._Peek(peek_i + 1).Type == NAME):
+                peek_i += 2
+            if self._Peek(peek_i).Type == OP and self._Peek(peek_i).Value == '(':
                 return self._ParseMatchClass()
             # 属性值模式 a.b（无括号）
             if self._Peek(1).Type == OP and self._Peek(1).Value == '.':
@@ -900,14 +904,10 @@ class Parser(ExprParserMixin):
         # 映射模式 {k: v, **rest}
         if tok.Type == OP and tok.Value == '{':
             return self._ParseMatchMapping()
-        # 字面量：数字/字符串/负号
-        if tok.Type == NUMBER or tok.Type == STRING or tok.Type == FSTRING:
-            value: N.expr = self.ParseExpr()
-            node = N.MatchValue(value=value)
-            self._FixLoc(node, start)
-            return node
-        if tok.Type == OP and tok.Value in ('-', '+'):
-            value = self.ParseExpr()
+        # 值模式：数字/字符串/f-string/带符号字面量（不消费顶层 '|'，留给 _ParsePattern 组 MatchOr）
+        if tok.Type == NUMBER or tok.Type == STRING or tok.Type == FSTRING or (
+                tok.Type == OP and tok.Value in ('-', '+')):
+            value: N.expr = self._ParsePatternValue()
             node = N.MatchValue(value=value)
             self._FixLoc(node, start)
             return node
@@ -921,6 +921,36 @@ class Parser(ExprParserMixin):
             return node
         raise SyntaxError(f"unexpected pattern token {tok.Type}({tok.Value!r})")
 
+    def _ParsePatternValue(self) -> N.expr:
+        """解析值模式表达式：带可选 +/- 前缀的字面量。
+
+        与 CPython 一致：'|' 是模式或分隔符，这里只解析单个字面量
+        （数字/字符串/f-string），不消费顶层 '|'。
+        """
+        start: Token = self._Peek()
+        tok: Token = self._Peek()
+        if tok.Type == OP and tok.Value in ('-', '+'):
+            op_tok: Token = self._Next()
+            inner: N.expr
+            if self._Peek().Type == NUMBER:
+                inner = self._ParseNumber()
+            elif self._Peek().Type in (STRING, FSTRING):
+                inner = self._ParseStringConcat()
+            else:
+                raise SyntaxError(
+                    f"expected literal after '{op_tok.Value}' in pattern at line {op_tok.Line}"
+                )
+            node: N.expr
+            if op_tok.Value == '-':
+                node = N.UnaryOp(op=N.USub(), operand=inner)
+            else:
+                node = N.UnaryOp(op=N.UAdd(), operand=inner)
+            self._FixLoc(node, start)
+            return node
+        if tok.Type == NUMBER:
+            return self._ParseNumber()
+        return self._ParseStringConcat()
+
     def _ParseMatchValueAttr(self) -> N.pattern:
         """解析值模式属性访问：a.b.c（无括号）。"""
         start: Token = self._Peek()