html {
  background: lightgray;
}
#all{
  display: flex;
  justify-content: center;
  text-align: center;
  align-items: center;
  width: 100%;
  margin: 40px;
}
#block {
  width: 400px;
  padding: 20px;
  background: white;
  border: 2px solid black;
}