body {
  background: #121212;
  color: #fff;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 40px;
}
.container {
  width: 700px;
  padding: 20px;
  background: #1e1e1e;
  border-radius: 10px;
  box-shadow: 0 0 10px #333;
  animation: fadeIn 1s ease-in-out;
}
input, button {
  width: 90%;
  margin: 10px 0;
  padding: 10px;
  border: none;
  border-radius: 5px;
  font-size: 1rem;
}
input {
  background: #2e2e2e;
  color: #fff;
}
button {
  background: #00b894;
  color: #fff;
  cursor: pointer;
  transition: background 0.3s ease;
  margin-bottom: 40px;
}
button i {
  margin-right: 8px;
}
button:hover {
  background: #019270;
}
#result {
  margin-top: 20px;
  padding: 10px;
  background: #2e2e2e;
  border-radius: 5px;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}