fix(Welcome): 修改创建家庭描述并调整加入家庭按钮样式

将"获取专属口令"改为"设置专属口令"以更准确描述功能
为加入家庭按钮添加底部边距以改善页面布局

 <!--
  * @Date: 2025-08-27 17:43:45
  * @LastEditors: hookehuyr hookehuyr@gmail.com
- * @LastEditTime: 2025-08-27 19:58:08
+ * @LastEditTime: 2025-08-28 21:45:22
  * @FilePath: /lls_program/src/pages/Welcome/index.vue
  * @Description: 文件描述
 -->
@@ -31,7 +31,7 @@
             <view>
               <h3 class="font-bold">创建家庭</h3>
               <p class="text-gray-600 text-sm">
-                家长创建家庭，获取专属口令
+                家长创建家庭，设置专属口令
               </p>
             </view>
           </view>
@@ -64,7 +64,7 @@
         <view @click="navigateTo('/pages/CreateFamily/index')" class="w-full py-3.5 bg-blue-500 text-white text-lg font-medium rounded-full text-center">
           创建家庭
         </view>
-        <view @click="navigateTo('/pages/JoinFamily/index')" class="w-full py-3.5 bg-white text-gray-800 text-lg font-medium rounded-full border border-gray-300 text-center">
+        <view @click="navigateTo('/pages/JoinFamily/index')" class="w-full py-3.5 bg-white text-gray-800 text-lg font-medium rounded-full border border-gray-300 text-center" style="margin-bottom: 1rem;">
           加入家庭
         </view>
       </view>