</span>
  <span class="nb">document</span><span class="p">.</span><span class="nx">addEventListener</span><span class="p">(</span><span class="s1">'mouseenter'</span><span class="p">,</span> <span class="nx">setPosition</span><span class="p">);</span>

  <span class="c1">// last known position</span>
  <span class="kd">var</span> <span class="nx">pos</span> <span class="o">=</span> <span class="p">{</span> <span class="na">x</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <s