html, body {
  height: 100%;
}
body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #f5f7fa 0%, #e9eef7 100%);
}
.container {
  width: 90%; max-width: 420px; margin: 8vh auto; padding: 20px; border-radius: 12px;
  background: #fff; box-shadow: 0 8px 24px rgba(0,0,0,.08);
}
h1 { font-size: 1.5rem; margin: 0 0 12px; }
.field { display: flex; flex-direction: column; margin-bottom: 12px; }
.field label { font-size: 0.9rem; color: #555; margin-bottom: 6px; }
.field input { padding: 8px 10px; border: 1px solid #ddd; border-radius: 6px; font-size: 1rem; }
button { padding: 10px 14px; border: none; border-radius: 6px; background: #4a90e2; color: white; font-size: 1rem; cursor: pointer; }
button:hover { background: #3b77c8; }
.status { margin-top: 8px; color: #555; }
.error { color: red; }
.result { font-size: 1.25rem; margin-top: 8px; }