diff --git a/web/static/app.css b/web/static/app.css
index 2f0afb6..b5f2642 100644
--- a/web/static/app.css
+++ b/web/static/app.css
@@ -511,4 +511,12 @@ body.dark-mode .user-menu,
 body.dark-mode .mobile-menu-inner{
   background:#111827;
   border-color:#374151;
-}
\ No newline at end of file
+}
+/* --- Release Announcement Modal --- */
+.modal { display:none; position:fixed; inset:0; background:rgba(0,0,0,.45); z-index:1000; }
+.modal.is-open { display:block; }
+.modal-card { background:#fff; max-width:640px; margin:10vh auto; border-radius:12px; box-shadow:0 10px 30px rgba(0,0,0,.2); overflow:hidden; }
+.modal-header, .modal-footer { padding:12px 16px; border-bottom:1px solid var(--border); }
+.modal-footer { border-top:1px solid var(--border); border-bottom:none; text-align:right; }
+.modal-body { padding:16px; }
+.modal-close { background:transparent; border:none; font-size:20px; line-height:1; cursor:pointer; }
\ No newline at end of file