* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
header {
  background-color: #f5f5f5;
  padding: 20px;
  text-align: center;
  font-weight: bold;
  color: #333;
  height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
