copy: execCommand fallback for embedded/iframe contexts

index.html

@@ -343,14 +343,23 @@ document.getElementById("closeall").onclick = () => {
 document.getElementById("anim").onclick = () => { animating = !animating; };
 document.getElementById("copy").onclick = async (e) => {
   const btn = e.currentTarget;
+  const text = document.getElementById("oneliner").textContent;
+  let ok = false;
   try {
-    await navigator.clipboard.writeText(
-      document.getElementById("oneliner").textContent);
-    btn.textContent = "Copied ✓";
-    btn.classList.add("ok");
+    await navigator.clipboard.writeText(text);
+    ok = true;
   } catch (err) {
-    btn.textContent = "Copy failed";
+    // clipboard API blocked (embedded iframe / permission): legacy fallback
+    const ta = document.createElement("textarea");
+    ta.value = text;
+    ta.style.position = "fixed"; ta.style.opacity = "0";
+    document.body.appendChild(ta);
+    ta.select();
+    try { ok = document.execCommand("copy"); } catch (e2) {}
+    ta.remove();
   }
+  btn.textContent = ok ? "Copied ✓" : "Copy failed";
+  btn.classList.toggle("ok", ok);
   clearTimeout(btn._t);
   btn._t = setTimeout(() => {
     btn.textContent = "Copy commands";