body {
  margin: 0;
  height: 100vh;
  background: #f0f0f0;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: Arial, Helvetica, sans-serif;
}

.clock {
  background: #ddd;
  padding: 20px 40px;
  font-size: 4em;
  color: #222;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0,0,0,0.2);
  text-align: center;
  font-family: 'Courier New', monospace;
}