首页宝宝来信卡改版：航空信封斜纹边、爱心邮戳、未读数气泡、手写标题、胶囊按钮

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

js/app.js

@@ -3,7 +3,7 @@
 (function () {
   'use strict';
   /* 页面版本号（YYMMDD+序号）：显示在「关于兜爸心选」页底部；bump 时同步 head 注释与 ?v= */
-  var VER = '26100150';
+  var VER = '26100151';
   const $ = (s, c) => (c || document).querySelector(s);
   const $$ = (s, c) => Array.from((c || document).querySelectorAll(s));
 
@@ -790,6 +790,7 @@
     $('#lcTitle').textContent = babyWord('来信');
     $('#lcDesc').textContent = desc;
     $('#lcLink').textContent = '读读' + babyWord('的话');
+    const num = $('#lcNum'); if (num) { const n = letters + replies; num.textContent = n > 99 ? '99+' : (n || ''); }
     card.classList.add('has-new');
     card.classList.remove('hide');
     if (body) body.classList.remove('no-letter');