body {
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(to right, #fdfbfb, #ebedee);
  margin: 0;
  padding: 2rem;
  color: #333;
  transition: background 0.5s ease;
}

.container {
  max-width: 700px;
  margin: auto;
  background: white;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 0 20px rgba(0,0,0,0.1);
  animation: fadeIn 0.8s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

textarea, input[type=text] {
  width: 100%;
  padding: 0.6rem;
  margin-top: 0.3rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

textarea:invalid, input:invalid {
  border-color: #b00020;
}

button {
  margin-top: 1.5rem;
  padding: 0.7rem 1.2rem;
  font-size: 1rem;
  background-color: #0078D7;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #005fa3;
}

.result {
  margin-top: 2rem;
  background: #f0f0f0;
  padding: 1rem;
  border-radius: 6px;
  white-space: pre-wrap;
}

.error {
  color: #b00020;
  margin-top: 1rem;
}
button[type="button"] {
  background-color: #e0e0e0;
  color: #333;
  margin-left: 0.5rem;
}

button[type="button"]:hover {
  background-color: #d0d0d0;
}