body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #f2f4f8;
  padding: 20px;
}

.calculator-container {
  background: white;
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  text-align: center;
  max-width: 500px;
  margin: auto;
  animation: fadeIn 1s ease-in-out;
}

h1 {
  font-size: 28px;
  margin-bottom: 10px;
  color: #333;
}

.description {
  font-size: 14px;
  color: #555;
  margin-bottom: 30px;
}

.calculator label {
  display: block;
  text-align: left;
  margin-bottom: 5px;
  color: #444;
}

.calculator input {
  width: 100%;
  padding: 10px;
  margin-bottom: 20px;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 16px;
}

button {
  width: 100%;
  padding: 12px;
  background-color: #66a6ff;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #558de8;
}

#result {
  margin-top: 20px;
  font-size: 18px;
  font-weight: bold;
  color: #333;
}

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