html {
  height: 100%;
}
body {
  height: 100%;
  background-color: rgb(224, 224, 224);
  display: flex;
  justify-content: center;
  align-items: center;
}
form {
  background-color: white;
  padding: 2rem;
  border-radius: 2rem;
  border: 1px solid black;
}

input:invalid {
  border: 2px dashed rgb(233, 138, 138);
}