body {
  background-color: grey;
  padding: 30px;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.form-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 400px;
  padding: 20px;
  background-color: #fff;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

#height, #weight {
  width: 100%;
  height: 40px;
  margin-bottom: 15px;
}

#weight-guide {
  margin-top: 15px;
}

#results {
  font-size: 35px;
  margin-top: 20px;
  color: rgb(241, 241, 241);
}

button {
  width: 100%;
  height: 45px;
  margin-top: 25px;
  background-color: #212121;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 25px;
}

h1 {
  padding-top: 25px;
  text-align: center;
}