fix(dev): rename .content to .sessions-content, fix :root accent override

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

posimai-dev/sessions.html

@@ -21,12 +21,12 @@
     <link rel="stylesheet" href="https://posimai-ui.vercel.app/v1/base.css">
     <script src="https://unpkg.com/lucide@0.344.0/dist/umd/lucide.min.js" integrity="sha384-tTkFttkBclaU1cloKwOi9xk3pbao3VZxTjLNBt8iFABWDBQibbAbWpVmO28zMuxq" crossorigin="anonymous"></script>
     <style>
-        :root {
+        [data-app-id="posimai-dev"] {
             --accent: #A78BFA;
             --accent-dim: rgba(167, 139, 250, 0.15);
             --dev-bg: #0C1221;
         }
-        [data-theme="light"] { --accent: #7C3AED; }
+        [data-app-id="posimai-dev"][data-theme="light"] { --accent: #7C3AED; }
 
         * { box-sizing: border-box; margin: 0; padding: 0; }
 
@@ -70,7 +70,7 @@
         }
         .back-btn:hover { background: rgba(167,139,250,0.25); }
 
-        .content {
+        .sessions-content {
             flex: 1;
             padding: 24px 16px;
             max-width: 800px;
@@ -198,7 +198,7 @@
     </a>
 </header>
 
-<div class="content">
+<div class="sessions-content">
     <div class="page-title">過去のセッション</div>
     <div class="page-subtitle" id="sessionCount">読み込み中...</div>