body {
  font-family: sans-serif;
  background: #f0f4f8;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
}
.box {
  background: white;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 4px 12px #00000022;
  text-align: center;
}
h1 { color: #0057ff; }