style: 优化回到顶部按钮毛玻璃样式

pages/index/index.wxss

@@ -1359,20 +1359,23 @@ wx-button:not([size=mini]) {
 /* 回到顶部按钮 */
 .back-to-top-btn {
   position: fixed;
-  right: 30rpx;
-  bottom: 200rpx;
-  width: 100rpx;
-  height: 100rpx;
-  background: linear-gradient(135deg, #1677ff 0%, #4096ff 100%);
+  right: 24rpx;
+  bottom: 180rpx;
+  width: 96rpx;
+  height: 96rpx;
+  background: rgba(255, 255, 255, 0.25);
+  backdrop-filter: blur(16rpx);
+  -webkit-backdrop-filter: blur(16rpx);
   border-radius: 50%;
   display: flex;
   flex-direction: column;
   justify-content: center;
   align-items: center;
-  box-shadow: 0 4rpx 16rpx rgba(22, 119, 255, 0.4);
+  box-shadow: 0 6rpx 20rpx rgba(0, 0, 0, 0.15);
+  border: 2rpx solid rgba(255, 255, 255, 0.4);
   opacity: 0;
   transform: translateY(20rpx);
-  transition: all 0.3s ease;
+  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
   z-index: 999;
   pointer-events: none;
 }
@@ -1384,13 +1387,17 @@ wx-button:not([size=mini]) {
 }
 
 .back-to-top-icon {
-  font-size: 36rpx;
-  color: white;
-  font-weight: bold;
+  font-size: 32rpx;
+  color: #1677ff;
+  font-weight: 600;
+  line-height: 1;
+  text-shadow: 0 1rpx 2rpx rgba(255, 255, 255, 0.8);
 }
 
 .back-to-top-text {
-  font-size: 18rpx;
-  color: white;
-  margin-top: 2rpx;
+  font-size: 16rpx;
+  color: #1677ff;
+  margin-top: 4rpx;
+  font-weight: 500;
+  text-shadow: 0 1rpx 2rpx rgba(255, 255, 255, 0.8);
 }