diff --git a/index.html b/index.html
index c9ef59c..3acc068 100644
--- a/index.html
+++ b/index.html
@@ -37,6 +37,9 @@
     <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>
+        /* base.css の main グローバルルールを打ち消す */
+        #main-content { padding: 0; max-width: none; width: 100%; margin: 0; }
+
         /* ── レイアウト ── */
         .wrap { max-width: 960px; margin: 0 auto; padding: 20px 16px calc(56px + env(safe-area-inset-bottom)); }
         .two-col { display: grid; gap: 12px; grid-template-columns: 1fr; }