<!doctype html>
<meta charset="utf-8">
<title>06 click coordinates</title>
<link rel="stylesheet" href="../_style.css">
<script src="../_lib.js"></script>
<body>
<main>
  <p>Goal: click the green button 5 times. Page rejects when clicks always land on the exact element center.</p>
  <button id="go" style="padding:24px 40px;font-size:18px;background:#1f7a1f;color:#fff;border:0;border-radius:6px">Click me (0/5)</button>
</main>
<script>
Challenge.init({ id: "click-coordinates", instructions: "click button 5 times; coordinates must vary" });
const btn = document.getElementById("go");
const pts = [];
btn.addEventListener("click", (e) => {
  const r = btn.getBoundingClientRect();
  const cx = r.left + r.width/2, cy = r.top + r.height/2;
  pts.push({ x: e.clientX, y: e.clientY, dx: e.clientX-cx, dy: e.clientY-cy });
  btn.textContent = `Click me (${pts.length}/5)`;
  if (pts.length < 5) return;
  const onCenter = pts.filter(p => Math.abs(p.dx) < 0.51 && Math.abs(p.dy) < 0.51).length;
  const unique = new Set(pts.map(p => `${p.x},${p.y}`)).size;
  Challenge.log("coords", { pts });
  if (onCenter >= 4) return Challenge.fail(`${onCenter}/5 clicks on exact center`);
  if (unique <= 1) return Challenge.fail(`only ${unique} unique click coords`);
  Challenge.pass(`${unique} unique coords, ${onCenter} on center`);
});
</script>
</body>