いいねボタンのハートを絵文字からフラットなテキスト文字に変更

❤️（絵文字）→ ♥（U+2665）に変更し端末依存のレンダリングを排除。
♡/♥ ともに CSS カラー（#bf283a）で統一した見た目に。

https://claude.ai/code/session_018sq37X4VGvDxwtnyyvQmFv

templates/blog_detail.html

@@ -85,7 +85,7 @@
     <div class="flex justify-center mb-8">
       <button id="like-btn" onclick="likeArticle('{{ article_id }}')"
               class="w-20 h-20 rounded-full border-2 border-[#e09099] dark:border-[#c07080] flex flex-col items-center justify-center gap-0.5 hover:bg-[#fdf0f2] dark:hover:bg-[#3d1a20] transition group">
-        <span id="like-icon" class="text-2xl transition-transform group-hover:scale-110 leading-none">♡</span>
+        <span id="like-icon" class="text-2xl transition-transform group-hover:scale-110 leading-none text-[#bf283a] dark:text-[#f08090]">♡</span>
         <span id="like-count" class="text-xs font-bold text-[#bf283a] dark:text-[#f08090] leading-none">{{ article.get("likes", 0) or 0 }}</span>
       </button>
     </div>
@@ -181,7 +181,7 @@ async function likeArticle(articleId) {
       btn.classList.remove('bg-[#fdf0f2]', 'dark:bg-[#3d1a20]');
     } else {
       localStorage.setItem(key, '1');
-      document.getElementById('like-icon').textContent = '❤️';
+      document.getElementById('like-icon').textContent = '♥';
       btn.classList.add('bg-[#fdf0f2]', 'dark:bg-[#3d1a20]');
     }
     document.getElementById('like-count').textContent = data.likes;
@@ -197,7 +197,7 @@ function showMsg(el, text, cls) {
 (function() {
   const articleId = '{{ article.get("id","") if article else "" }}';
   if (articleId && localStorage.getItem(`liked_${articleId}`)) {
-    document.getElementById('like-icon').textContent = '❤️';
+    document.getElementById('like-icon').textContent = '♥';
     const btn = document.getElementById('like-btn');
     if (btn) btn.classList.add('bg-[#fdf0f2]', 'dark:bg-[#3d1a20]');
   }