* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;  
  overflow: hidden;
}

body {
  background-color: black;
  font-family: Arial, sans-serif;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

footer {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 12px;
  color: #ccc;
}

footer span {
  color: #fff;
}

#popup {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 14px;
  color: #fff;
  font-family: 'Arial', sans-serif;
  padding: 15px;
  background-color: rgba(0, 0, 0, 0.7);
  border-radius: 8px;
  text-align: center;
  z-index: 10;
  display: block;
}