static/gr_empty.html

<div style="
  width: 100%;
  height: 850px;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: #f0f8ff;
  font-family: Arial, sans-serif;
  font-size: 20px;
  color: #333;
">
  <b>Press the <span style='color:#007BFF;'>Run Query</span> button to start exploring!</b>
</div>