diff --git a/vpsdk/vpui.vp b/vpsdk/vpui.vp
index 3d077cb..7d2f605 100644
--- a/vpsdk/vpui.vp
+++ b/vpsdk/vpui.vp
@@ -596,8 +596,31 @@ virtual class Label(Widget):
             self.text[i] = ch
             i += 1
         self.text[i] = 0
+        # Label 没有显式 w/h 参数：自然尺寸必须由文本推出。否则 pack 拿到的请求尺寸是
+        # 0×0 ⇒ 不占布局空间，且 PACK_BOTTOM/非 fill 时会被贴到可视区域之外（文字被裁掉）。
+        self._fit_natural()
         _register_widget(master, Widget*(self))
 
+    # 按当前 text 计算自然尺寸：宽取最长行，高取行数（多行 Label 也成立）。
+    def _fit_natural(self):
+        line_chars: int = 0
+        max_chars: int = 0
+        lines: int = 1
+        i: int = 0
+        while i < 64:
+            ch: char = self.text[i]
+            if ch == 0: break
+            if ch == 10:
+                if line_chars > max_chars: max_chars = line_chars
+                line_chars = 0
+                lines += 1
+            else:
+                line_chars += 1
+            i += 1
+        if line_chars > max_chars: max_chars = line_chars
+        self.w = max_chars * CHAR_W
+        self.h = lines * CHAR_H
+
     def draw(self, fb: uint32*, fw: int, fh: int):
         _draw_text(fb, fw, fh, self.x, self.y, &self.text[0], self.color)
 
@@ -613,6 +636,7 @@ virtual class Label(Widget):
                 if ch == 0: break
                 i += 1
             self.text[i] = 0
+            self._fit_natural()
         if color is not None:
             self.color = color
 
@@ -1649,7 +1673,6 @@ virtual class Tk(Wm, Misc):
         # 窗口槽已回收（用户点了关闭）：立即返回，不再触碰共享 arena / flush。
         if self.win_id < 0: return
         if window.is_active(self.win_id) == 0: return
-        self._do_layout()
         self.buf = window.get_winbuf(self.win_id)
         sz: int = window.get_win_size(self.win_id)
         if sz != 0:
@@ -1657,6 +1680,8 @@ virtual class Tk(Wm, Misc):
             self.bh = sz & 0xFFFF
         if not self.buf: return
         if self.bw <= 0 or self.bh <= 0: return
+        # 先刷新尺寸再布局：窗口 resize 后若沿用上一帧的 bw/bh，布局会滞后一帧。
+        self._do_layout()
         # 【诊断·临时】每个进程第一次真正走到 redraw 时打一行：证明"app 侧开始绘制了"，
         # 并给出它拿到的缓冲地址/尺寸（与 explorer 侧 shm0/flush 对照）。
         # `_first` 只在本帧为 1：下面的 st1..st4 分段打点也只打这一次，用于定位
@@ -1742,13 +1767,17 @@ virtual class Tk(Wm, Misc):
                 py: int = _g_wl_pady[i]
                 ww: int = w.w
                 wh: int = w.h
+                # 交叉轴上未 fill 时按 Tk 默认 anchor=center 居中；沿 pack 方向仍贴腔体边缘 +
+                # padding（与 tkinter 一致）。此前一律贴左上，导致不 fill 的控件全部挤在左边缘。
                 if side == PACK_TOP:
                     if fill == FILL_X or fill == FILL_BOTH:
                         ww = cav_w - 2 * px
+                        w.x = cav_x + px
+                    else:
+                        w.x = cav_x + px + (cav_w - 2 * px - ww) / 2
                     if expand:
                         if fill == FILL_Y or fill == FILL_BOTH:
                             wh = cav_h - 2 * py
-                    w.x = cav_x + px
                     w.y = cav_y + py
                     w.w = ww
                     w.h = wh
@@ -1757,10 +1786,12 @@ virtual class Tk(Wm, Misc):
                 elif side == PACK_BOTTOM:
                     if fill == FILL_X or fill == FILL_BOTH:
                         ww = cav_w - 2 * px
+                        w.x = cav_x + px
+                    else:
+                        w.x = cav_x + px + (cav_w - 2 * px - ww) / 2
                     if expand:
                         if fill == FILL_Y or fill == FILL_BOTH:
                             wh = cav_h - 2 * py
-                    w.x = cav_x + px
                     w.y = cav_y + cav_h - wh - py
                     w.w = ww
                     w.h = wh
@@ -1768,11 +1799,13 @@ virtual class Tk(Wm, Misc):
                 elif side == PACK_LEFT:
                     if fill == FILL_Y or fill == FILL_BOTH:
                         wh = cav_h - 2 * py
+                        w.y = cav_y + py
+                    else:
+                        w.y = cav_y + py + (cav_h - 2 * py - wh) / 2
                     if expand:
                         if fill == FILL_X or fill == FILL_BOTH:
                             ww = cav_w - 2 * px
                     w.x = cav_x + px
-                    w.y = cav_y + py
                     w.w = ww
                     w.h = wh
                     cav_x += ww + 2 * px
@@ -1780,11 +1813,13 @@ virtual class Tk(Wm, Misc):
                 elif side == PACK_RIGHT:
                     if fill == FILL_Y or fill == FILL_BOTH:
                         wh = cav_h - 2 * py
+                        w.y = cav_y + py
+                    else:
+                        w.y = cav_y + py + (cav_h - 2 * py - wh) / 2
                     if expand:
                         if fill == FILL_X or fill == FILL_BOTH:
                             ww = cav_w - 2 * px
                     w.x = cav_x + cav_w - ww - px
-                    w.y = cav_y + py
                     w.w = ww
                     w.h = wh
                     cav_w -= ww + 2 * px