* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Tahoma, Arial, sans-serif;
  background: #f5f6f8;
  color: #1f2937;
}
.box {
  max-width: 380px;
  margin: 80px auto;
  padding: 28px;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}
.box h1 { margin-top: 0; font-size: 1.5rem; }
.box label { display: block; margin: 14px 0 6px; font-weight: bold; }
.box input {
  width: 100%;
  padding: 10px;
  font-size: 1rem;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
}
.box button {
  width: 100%;
  margin-top: 20px;
  padding: 12px;
  font-size: 1rem;
  color: #fff;
  background: #1d4ed8;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}
.box button:disabled { opacity: 0.6; cursor: wait; }
#message { color: #b91c1c; min-height: 1.4em; margin: 12px 0 0; }