* {
  box-sizing: border-box;
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
}

.form-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: #f2f2f2;
  border-radius: 5px;
  padding: 1rem;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
  width: 100%;
  max-width: 600px;
}

form {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

label {
  font-size: 1.5rem;
  margin-right: 0.5rem;
}

input {
  font-size: 1.5rem;
  padding: 0.5rem;
  margin: 0 0.5rem 0.5rem 0.5rem;
  border-radius: 5px;
  border: none;
  text-align: center;
  background-color: #fff;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.2);
  flex: 1 1 200px;
}

button {
  font-size: 1.5rem;
  padding: 0.5rem 1rem;
  margin: 0 0.5rem;
  border-radius: 5px;
  border: none;
  background-color: #007bff;
  color: #fff;
  cursor: pointer;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.2);
  flex: 1 1 auto;
}

#answer-container {
  margin-top: 1rem;
}

#answer {
  font-size: 2rem;
  font-weight: bold;
}

@media only screen and (max-width: 600px) {
  h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
  }

  form {
    flex-direction: column;
    align-items: flex-start;
  }

  input {
    margin: 0.5rem 0 0.5rem 0;
    width: 100%;
  }

  button {
    margin-top: 0.5rem;
    width: 100%;
  }
}