body {
  font-family: Arial, sans-serif;
  text-align: center;
}

h1 {
  color: #333;
}

.calculator {
  margin: 20px;
  padding: 20px;
  border: 2px solid #333;
  border-radius: 25px;
 
  margin: 0 auto;
  box-shadow: 0 0 70px rgba(0, 0, 0, 0.2);
}

label {
  display: block;
  margin-top: 10px;
}

input {
  width: 100%;
  padding: 5px;
  margin-top: 5px;
}

button {
  margin-top: 10px;
  background-color: blue;
  color: yellow;
  border: none;
  padding: 10px 20px;
  border-radius: 15px;
  cursor: pointer;
}

button:hover {
  background-color: #ffdb58;
}

#result {
  background-color: yellow;
  color: green;
  border-width: 1px;
  padding: 5px;
  border-radius: 15px;
  width: 60%;
}

#voltageTypeContainer {
  display: block;
}

#voltageTypeContainer.hidden {
  display: none;
}