early version: modular block files, full template set, tab UI, OpenGL defaults

error.js

@@ -0,0 +1,31 @@
+// ── Error modal ───────────────────────────────────────────────────────────────
+//
+// A simple overlay modal that displays -ACK! with a custom message.
+// Depends on: dom.js ($)
+//
+
+/**
+ * Shows the error modal with the given message.
+ * The overlay is absolutely positioned and blocks all interaction until dismissed.
+ * @param {string} msg - message to display inside the error box
+ */
+function showError(msg) {
+  const el = $("#error-overlay");
+  el.querySelector(".error-msg").textContent = msg;
+  el.classList.add("active");
+}
+
+/**
+ * Hides the error modal. Triggered by clicking the × button,
+ * the overlay backdrop, or called programmatically.
+ * @param {MouseEvent} [ev] - event to check target matching
+ */
+function closeError(ev) {
+  if (
+    !ev ||
+    ev.target === ev.currentTarget ||
+    ev.target.classList.contains("error-close")
+  ) {
+    $("#error-overlay").classList.remove("active");
+  }
+}