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

body {
  font-family: Arial, sans-serif;
  background: #222;
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px;
}

main {
  max-width: 100%;
  width: 370px;
}

.message {
  position: fixed;
  top: 20px;
  right: 20px;
  background: #333;
  color: #fff;
  padding: 10px 20px;
  border-radius: 5px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.message--visible {
  opacity: 1;
}