diff --git a/app/index.html b/app/index.html
index 9e00cb5..8d00029 100644
--- a/app/index.html
+++ b/app/index.html
@@ -935,7 +935,7 @@ function buildForm() {
   </div>
 
   <!-- Action row -->
-  <div style="display:flex;gap:10px;margin-top:8px">
+  <div id="action-row" style="display:flex;gap:10px;margin-top:8px">
     <button type="button" id="btn-save" class="kb-btn kb-btn--ghost kb-btn--lg" style="flex:2" onclick="saveInvoice()">${t("save")}</button>
     <button type="button" id="btn-validate" class="kb-btn kb-btn--ghost kb-btn--lg" style="flex:2" onclick="validateInvoice()">${t("validate")}</button>
     <button type="submit" id="btn-generate" class="kb-btn kb-btn--primary kb-btn--lg" style="flex:6">
@@ -1466,7 +1466,8 @@ function validateInvoice() {
     msg.style.color = "#e74c3c";
     msg.innerHTML = errors.map(e => `• ${e}`).join("<br>");
   }
-  btn.closest("div").after(msg);
+  const row = document.getElementById("action-row");
+  if (row) row.after(msg);
   setTimeout(() => msg.remove(), 5000);
 }