fix: index page center-aligned layout for device card

miniprogram/pages/index/index.wxml

@@ -18,18 +18,14 @@
 
   <view class="page-content" wx:if="{{!loading && hasDevice}}">
     <view class="device-card">
-      <view class="device-card-top">
-        <view class="device-icon">💆</view>
-        <view class="device-info">
-          <view class="device-name">{{deviceName || '我的光面膜'}}</view>
-          <view class="device-meta">
+      <view class="device-card-icon">💆</view>
+      <view class="device-card-name">{{deviceName || '光子美容仪'}}</view>
+      <view class="device-card-status">
         <text class="status-badge status-badge-green" wx:if="{{connected}}">已连接</text>
         <text class="status-badge" style="background:#ccc;" wx:else>未连接</text>
-            <text class="device-battery-text" wx:if="{{connected}}">🔋 {{battery}}%</text>
+        <text class="device-card-battery" wx:if="{{connected}}">🔋 {{battery}}%</text>
       </view>
-        </view>
-      </view>
-      <button class="btn-reconnect" bindtap="onConnectBle" wx:if="{{hasDevice && !connected}}">重新连接</button>
+      <button class="btn-reconnect" bindtap="onConnectBle" wx:if="{{!connected}}">重新连接</button>
     </view>
 
     <view class="sub-info" bindtap="onViewSubscription">

miniprogram/pages/index/index.wxss

@@ -22,38 +22,31 @@
 .device-card {
   background: #fff;
   border-radius: 16rpx;
-  padding: 28rpx;
+  padding: 36rpx 28rpx;
+  text-align: center;
 }
 
-.device-card-top {
-  display: flex;
-  align-items: center;
-  gap: 20rpx;
+.device-card-icon {
+  font-size: 80rpx;
+  margin-bottom: 12rpx;
 }
 
-.device-icon {
-  font-size: 64rpx;
-  flex-shrink: 0;
-}
-
-.device-info {
-  flex: 1;
-}
-
-.device-name {
-  font-size: 32rpx;
+.device-card-name {
+  font-size: 34rpx;
   font-weight: 600;
   color: #333;
+  margin-bottom: 16rpx;
+}
+
+.device-card-status {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 16rpx;
   margin-bottom: 8rpx;
 }
 
-.device-meta {
-  display: flex;
-  align-items: center;
-  gap: 16rpx;
-}
-
-.device-battery-text {
+.device-card-battery {
   font-size: 24rpx;
   color: #666;
 }
@@ -61,7 +54,7 @@
 .btn-reconnect {
   display: block;
   width: 100%;
-  margin-top: 20rpx;
+  margin-top: 24rpx;
   padding: 20rpx;
   background: #f5f5f5;
   color: #E6508C;
@@ -91,6 +84,7 @@
   padding: 24rpx;
   margin-top: 20rpx;
 }
+
 .sub-info-left {
   display: flex;
   align-items: center;
@@ -98,9 +92,11 @@
   font-size: 28rpx;
   color: #333;
 }
+
 .sub-info-icon {
   font-size: 32rpx;
 }
+
 .sub-info-arrow {
   color: #999;
   font-size: 32rpx;