style(miniprogram): 更新分享按钮样式

- 修改学校和船厂页面的分享按钮背景色为 #576b95
- 调整分享按钮的文本颜色为白色
- 移除分享按钮的内边距和边框样式
- 调整分享按钮的外边距

miniprogram/pages/school/school.wxss

@@ -125,13 +125,10 @@
 }
 
 .share-btn {
-  background-color: #07c160;
+  background-color: #576b95;
   color: #fff;
   font-size: 28rpx;
-  padding: 16rpx 32rpx;
-  border-radius: 8rpx;
-  border: none;
-  margin-top: 20rpx;
+  margin-bottom: 10px;
 }
 
 .share-btn::after {

miniprogram/pages/shipyard/shipyard.wxss

@@ -99,13 +99,10 @@
 }
 
 .share-btn {
-  width: 90%;
-  margin: 20rpx auto;
-  background-color: #f8f8f8;
-  color: #333;
-  border: 1rpx solid #ddd;
-  border-radius: 8rpx;
+  background-color: #576b95;
+  color: #fff;
   font-size: 28rpx;
+  margin-bottom: 20px;
 }
 
 .contact-text {