diff --git a/main_app.py b/main_app.py
index 6512fd8..9809c3d 100644
--- a/main_app.py
+++ b/main_app.py
@@ -42,6 +42,7 @@ def main():
                 # Define preset video mapping (display name -> filename)
                 preset_videos = {
                     "六字诀": "liuzi.mp4",
+                    "六字诀精简": "liuzi-short.mp4",
                     # Add more preset videos here:
                     # "太极拳": "taiji.mp4",
                     # "八段锦": "baduanjin.mp4",
@@ -160,26 +161,36 @@ def main():
                         st.session_state.show_preview = False
                 
                 else:
-                    # 主控制按钮（大按钮）
-                    main_btn_col1, main_btn_col2, main_btn_col3 = st.columns(3)
-                    
-                    with main_btn_col1:
-                        if st.button("📷 预览摄像头", use_container_width=True, help="先预览摄像头调整位置"):
-                            if app.body_detector is None:
-                                st.error("⚠️ 请先在侧边栏初始化系统")
-                            else:
-                                st.session_state.show_preview = True
-                                st.rerun()
-                    
-                    with main_btn_col2:
-                        if st.button("🚀 直接开始比较", use_container_width=True, help="直接开始动作比较"):
-                            if app.body_detector is None:
-                                st.error("⚠️ 请先在侧边栏初始化系统")
-                            else:
-                                app.start_comparison(video_path)
-                    
-                    with main_btn_col3:
-                        st.markdown("")  # 占位
+                    if 'start_main_comparison' not in st.session_state:
+                        st.session_state.start_main_comparison = False
+                    # 如果不处于比较状态，则显示主控制按钮
+                    if not st.session_state.start_main_comparison:
+                        main_btn_col1, main_btn_col2, main_btn_col3 = st.columns(3)
+
+                        with main_btn_col1:
+                            if st.button("📷 预览摄像头", use_container_width=True, help="先预览摄像头调整位置"):
+                                if app.body_detector is None:
+                                    st.error("⚠️ 请先在侧边栏初始化系统")
+                                else:
+                                    st.session_state.show_preview = True
+                                    st.rerun()
+                        
+                        with main_btn_col2:
+                            if st.button("🚀 直接开始比较", use_container_width=True, help="直接开始动作比较"):
+                                if app.body_detector is None:
+                                    st.error("⚠️ 请先在侧边栏初始化系统")
+                                else:
+                                    st.session_state.start_main_comparison = True
+                                    st.rerun()
+                        
+                        with main_btn_col3:
+                            st.markdown("")  # 占位
+
+                    if st.session_state.start_main_comparison:
+                        app.start_comparison(video_path)
+                        # 比较结束后，重置状态，以便下次可以重新显示主按钮
+                        st.session_state.start_main_comparison = False
+                        st.rerun() # 强制重跑以显示主按钮界面
             
             except Exception as e:
                 st.error(f"❌ 处理视频时出现错误: {str(e)}")
diff --git a/motion_app.py b/motion_app.py
index d5ff693..981560f 100644
--- a/motion_app.py
+++ b/motion_app.py
@@ -36,7 +36,7 @@ class MotionComparisonApp:
             st.session_state.comparison_state = {'is_running': False, 'should_stop': False, 'should_restart': False}
 
     def get_display_resolution(self):
-        modes = {'high': (1280, 800), 'medium': (960, 720), 'low': (640, 480)}
+        modes = {'high': (1024, 576), 'medium': (960, 720), 'low': (640, 480)}
         mode = self.display_settings.get('resolution_mode', 'medium')
         return modes.get(mode, (960, 720))
 
@@ -74,6 +74,7 @@ class MotionComparisonApp:
         try:
             self.webcam_cap = cv2.VideoCapture(0)
             if self.webcam_cap.isOpened():
+                self.webcam_cap.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter_fourcc('M', 'J', 'P', 'G'))
                 width, height = self.get_display_resolution()
                 self.webcam_cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)
                 self.webcam_cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)