.js-warning {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 20px;
  background-color: #f44336;
  color: white;
  text-align: center;
  font-family: Arial, sans-serif;
  font-size: 16px;
  z-index: 9999;
}