style(SharePoster): 修改底部提示文字并添加关闭按钮样式

@@ -43,10 +43,10 @@
             </div>
 
             <!-- 底部提示与关闭按钮 -->
-            <div class="mt-3 text-center text-gray-500 text-xs">长按图片保存至手机</div>
-            <!-- <div class="mt-4">
-                <button class="w-full bg-white border border-green-500 text-green-600 py-2 rounded-lg" @click="close">关闭</button>
-            </div> -->
+            <div class="mt-3 text-center text-gray-500 text-xs">长按图片保存</div>
+            <div class="mt-4">
+                <button class="w-full bg-green-500 text-white py-2 rounded-lg" @click="close">关闭</button>
+            </div>
         </div>
     </van-popup>
     <van-back-top right="5vw" bottom="25vh" offset="600" />