body {
  font-family: 'Poppins', sans-serif;
  background: linear-gradient(to right, #232526, #414345);
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 30px;
}

h1 {
  font-size: 3rem;
  margin-bottom: 20px;
}

.calculator {
  background: #2c3e50;
  padding: 30px;
  border-radius: 20px;
  max-width: 600px;
  width: 100%;
  box-shadow: 0 0 20px rgba(0,0,0,0.5);
}

label {
  display: block;
  margin: 15px 0 5px;
  font-size: 1.1rem;
}

input, select {
  width: 100%;
  padding: 12px;
  border-radius: 10px;
  border: none;
  font-size: 1rem;
}

button {
  margin-top: 20px;
  padding: 15px;
  background: #27ae60;
  border: none;
  border-radius: 10px;
  font-size: 1.2rem;
  color: #fff;
  cursor: pointer;
}

button:hover {
  background: #2ecc71;
}

.result {
  margin-top: 20px;
  font-size: 1.3rem;
  text-align: center;
}

canvas {
  margin-top: 30px;
}