body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}
.card {
  background: rgba(0,0,0,0.4);
  padding: 30px;
  border-radius: 16px;
  width: 100%;
  max-width: 400px;
  text-align: center;
  box-shadow: 0 20px 40px rgba(0,0,0,.4);
}
h1,h2 { margin-bottom: 20px; }
input {
  width: 100%;
  padding: 12px;
  margin: 10px 0;
  border-radius: 8px;
  border: none;
}
button {
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: 10px;
  background: #00ffcc;
  color: #000;
  font-size: 16px;
  cursor: pointer;
}
button:hover { opacity: .85; }