fix: 调整用户体重卡片样式，优化动画容器高度和字体大小

app/(tabs)/statistics.tsx

@@ -573,7 +573,7 @@ export default function ExploreScreen() {
     <View style={styles.container}>
       {/* 背景渐变 */}
       <LinearGradient
-        colors={['#b9e4f5ff', '#b3f6f8ff', '#e6e5e8ff', '#F3F4F6']}
+        colors={['#f8f3faff', '#b3f6f8ff', '#bcf1f7ff', '#d3edf8ff']}
         style={styles.gradientBackground}
         start={{ x: 0, y: 0 }}
         end={{ x: 0, y: 1 }}

components/weight/WeightHistoryCard.tsx

@@ -52,7 +52,6 @@ export function WeightHistoryCard() {
   const themeColors = Colors[colorScheme ?? 'light'];
 
   const hasWeight = userProfile?.weight && parseFloat(userProfile.weight) > 0;
-  const hasHeight = userProfile?.height && parseFloat(userProfile.height) > 0;
 
   // BMI 计算
   const canCalculate = canCalculateBMI(
@@ -632,12 +631,12 @@ const styles = StyleSheet.create({
   animationContainer: {
     position: 'relative',
     overflow: 'hidden',
-    minHeight: 40,
+    minHeight: 50,
   },
   summaryInfo: {
     position: 'absolute',
     width: '100%',
-    marginTop: 10,
+    marginTop: 8,
   },
   chartContainer: {
     position: 'absolute',
@@ -682,13 +681,14 @@ const styles = StyleSheet.create({
     minWidth: 0,
   },
   summaryLabel: {
-    fontSize: 11,
+    fontSize: 12,
     color: '#687076',
     marginBottom: 3,
   },
   summaryValue: {
-    fontSize: 13,
-    fontWeight: '700',
+    fontSize: 14,
+    marginTop: 2,
+    fontWeight: '600',
     color: '#192126',
   },