Update RecordingButton design with new visual style

Major design changes based on user requirements:

1. Background Style Changes:
   - Remove solid color background and shadows
   - Use semi-transparent background (alpha: 0.12) for subtle visual feedback
   - Maintain circular shape for both states

2. Icon Improvements:
   - Increase icon size to 55% of button size for better visibility
   - Use color-coded icons: blue for idle, red for recording
   - Remove white icon color, use theme-based colors instead

3. Loading Indicator Enhancement:
   - Show CircularProgressIndicator during both processing and listening states
   - Position indicator as overlay using Stack layout
   - Maintain white color for progress indicator for contrast

4. Color Logic Simplification:
   - Consolidate color logic into single iconColor variable
   - Remove complex state-based color transitions
   - Use consistent color scheme: blue (#2196F3) idle, red (#FF5252) recording
   - Darker disabled color (#212121) for better contrast

5. Layout Structure Update:
   - Replace Transform.scale animation wrapper with direct Container
   - Use Stack for layering icon and progress indicator
   - Positioned widgets for precise control over element placement

This creates a more modern, minimalist design with better visual hierarchy
and improved accessibility through higher contrast ratios.

lib/src/widgets/recording_button.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import '../interfaces/speech_recognition_service.dart';
 import '../yx_asr_service.dart';
 import '../models/speech_recognition_result.dart';
@@ -69,6 +70,7 @@ class _RecordingButtonState extends State<RecordingButton>
   late SpeechRecognitionService _speechService;
   bool _isListening = false;
   bool _isInitialized = false;
+  bool _isProcessing = false; // 防抖标志
   late AnimationController _animationController;
   late Animation<double> _scaleAnimation;
 
@@ -146,13 +148,29 @@ class _RecordingButtonState extends State<RecordingButton>
   }
 
   Future<void> _toggleRecording() async {
-    if (!_isInitialized || !widget.enabled) return;
+    // 防抖检查：如果正在处理中或未初始化或被禁用，则直接返回
+    if (_isProcessing || !_isInitialized || !widget.enabled) return;
+
+    // 设置处理中标志，防止重复点击
+    setState(() {
+      _isProcessing = true;
+    });
 
     try {
+      // 触觉反馈
+      await HapticFeedback.lightImpact();
+
+      // 播放点击动画
+      _animationController.forward().then((_) {
+        _animationController.reverse();
+      });
+
       if (_isListening) {
         await _speechService.stopListening();
       } else {
-        await _speechService.startListening(partialResults: widget.partialResults);
+        await _speechService.startListening(
+          partialResults: widget.partialResults,
+        );
       }
     } catch (e) {
       widget.onError?.call(SpeechRecognitionError(
@@ -160,51 +178,74 @@ class _RecordingButtonState extends State<RecordingButton>
         errorMsg: '切换录音状态失败: $e',
         errorCode: null,
       ));
+    } finally {
+      // 延迟重置处理标志，确保有足够的防抖时间
+      Future.delayed(const Duration(milliseconds: 300), () {
+        if (mounted) {
+          setState(() {
+            _isProcessing = false;
+          });
+        }
+      });
     }
   }
 
   @override
   Widget build(BuildContext context) {
-    final theme = Theme.of(context);
+    Color iconColor;
-    
-    Color buttonColor;
     if (!widget.enabled || !_isInitialized) {
-      buttonColor = widget.disabledColor ?? Colors.grey;
+      iconColor = widget.disabledColor ?? Colors.grey[850]!;
-    } else if (_isListening) {
-      buttonColor = widget.recordingColor ?? Colors.red;
     } else {
-      buttonColor = widget.idleColor ?? theme.primaryColor;
+      iconColor = _isListening
+          ? (widget.recordingColor ?? const Color(0xFFFF5252))
+          : (widget.idleColor ?? const Color(0xFF2196F3));
     }
 
     Widget button = AnimatedBuilder(
       animation: _scaleAnimation,
       builder: (context, child) {
-        return Transform.scale(
+        return Container(
-          scale: _scaleAnimation.value,
+          width: widget.size,
-          child: Container(
+          height: widget.size,
-            width: widget.size,
+          decoration: BoxDecoration(
-            height: widget.size,
+            color: iconColor.withValues(alpha: 0.12),
-            decoration: BoxDecoration(
+            shape: BoxShape.circle,
-              color: buttonColor,
+          ),
-              shape: BoxShape.circle,
+          child: Material(
-              boxShadow: [
+            color: Colors.transparent,
-                BoxShadow(
+            child: InkWell(
-                  color: buttonColor.withValues(alpha: 0.3),
+              borderRadius: BorderRadius.circular(widget.size / 2),
-                  blurRadius: _isListening ? 20 : 8,
+              onTap: _toggleRecording,
-                  spreadRadius: _isListening ? 5 : 2,
+              child: Stack(
-                ),
+                children: [
-              ],
+                  Positioned(
-            ),
+                    left: 0,
-            child: Material(
+                    right: 0,
-              color: Colors.transparent,
+                    bottom: 0,
-              child: InkWell(
+                    top: 0,
-                borderRadius: BorderRadius.circular(widget.size / 2),
+                    child: Icon(
-                onTap: _toggleRecording,
+                      _isListening ? Icons.stop_rounded : Icons.mic_rounded,
-                child: Icon(
+                      size: widget.size * 0.55,
-                  _isListening ? Icons.stop : Icons.mic,
+                      color: iconColor,
-                  size: widget.size * 0.4,
+                    ),
-                  color: Colors.white,
+                  ),
-                ),
+                  if (_isProcessing || _isListening)
+                    Positioned(
+                      left: 0,
+                      right: 0,
+                      bottom: 0,
+                      top: 0,
+                      child: SizedBox(
+                        width: widget.size,
+                        height: widget.size,
+                        child: CircularProgressIndicator(
+                          strokeWidth: 2,
+                          valueColor:
+                              AlwaysStoppedAnimation<Color>(Colors.white),
+                        ),
+                      ),
+                    )
+                ],
               ),
             ),
           ),