body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text",
               "Segoe UI", Roboto, sans-serif;
  background: #f2f2f7;
  color: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}
.container {
  width: 100%;
  max-width: 420px;
  padding: 1.5rem;
}
.card {
  margin: 2rem;
  background: rgba(255, 255, 255, 0.8);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 20px;
  padding: 2rem;
  box-shadow:
    0 10px 30px rgba(0,0,0,0.08),
    0 1px 2px rgba(0,0,0,0.05);
}

button {
  width: 100%;
  height: 3.2rem;
  margin-bottom: 0.5rem;
  border: none;
  border-radius: 12px;
  background: #007aff;
  color: white;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}
button:active {
  transform: scale(0.97);
  background: #0066d6;
}
/* darkmode */
@media (prefers-color-scheme: dark) {
  body {
    background: #000;
    color: #fff;
  }
  .card {
    background: rgba(28, 28, 30, 0.8);
  }
  button {
    background: #0a84ff;
  }
  button:active {
    background: #0060df;
  }
}