body {
  font-family: system-ui, sans-serif;
  background: #f7f7f7;
  margin: 0;
  padding: 20px;
}

.card {
  max-width: 420px;
  margin: auto;
  background: #fff;
  padding: 24px;
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

h1 {
  margin-top: 0;
  font-size: 22px;
}

.subtitle {
  color: #666;
  font-size: 14px;
}

button {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 10px;
  background: #2563eb;
  color: #fff;
  font-size: 16px;
  cursor: pointer;
}

#result p {
  margin: 8px 0;
  font-size: 14px;
}