body::before,
body::after {
  content: "MOCK WEBSITE – NOT THE REAL THING";
  position: sticky;
  left: 0;
  right: 0;
  z-index: 9999;
  display: block;
  padding: 10px 16px;
  font: bold 16px/1.3 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  background: #ffeb3b;
  color: #000;
  text-align: center;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
  pointer-events: none;
}

body::before {
  top: 0;
}

body::after {
  bottom: 0;
}