Change folder hierarchy

_extensions/notes/exo.js

@@ -0,0 +1,33 @@
+// exo — hints unlock one by one; everything unfolds for printing
+(function () {
+  // block opening a locked hint
+  document.addEventListener("click", function (e) {
+    var s = e.target.closest ? e.target.closest("details.exo-hint.exo-locked > summary") : null;
+    if (s) e.preventDefault();
+  });
+
+  // opening hint n unlocks hint n+1 (toggle doesn't bubble: use capture)
+  document.addEventListener("toggle", function (e) {
+    var d = e.target;
+    if (!d.classList || !d.classList.contains("exo-hint") || !d.open) return;
+    var next = d.nextElementSibling;
+    while (next && !(next.tagName === "DETAILS" && next.classList.contains("exo-hint"))) {
+      next = next.nextElementSibling;
+    }
+    if (next) next.classList.remove("exo-locked");
+  }, true);
+
+  // print: open all hints/solutions, restore afterwards
+  window.addEventListener("beforeprint", function () {
+    document.querySelectorAll(".exo details").forEach(function (d) {
+      d.dataset.exoWasOpen = d.open ? "1" : "0";
+      d.open = true;
+    });
+  });
+  window.addEventListener("afterprint", function () {
+    document.querySelectorAll(".exo details").forEach(function (d) {
+      d.open = d.dataset.exoWasOpen === "1";
+      delete d.dataset.exoWasOpen;
+    });
+  });
+})();