body {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
  background-color: #1f313b;
}

.container {
  width: 70%;
  position: relative;
  height: 32em;
  margin: auto;
  margin-top: 5em;
  border-radius: 10px;
  box-shadow: 14px 14px 20px #141e27, -14px -14px 20px #121314;
}

.preface {
  float: left;
  width: 50%;
  height: 32em;
  background-color: #141e27;
  color: #fff;
  border-radius: 10px 0 0 10px;
  text-align: center;
}

.text {
  margin-top: 12em;
}

form {
  background-color: #eaedf2;
  float: right;
  width: 50%;
  height: 32em;
  border-radius: 0 10px 10px 0;
  text-align: center;
  margin: auto;
}

.weight,
.height,
.gender {
  margin-top: 1.5em;
}

button {
  margin-top: 4em;
}

label {
  font-size: 1.5em;
}

input,
select,
button {
  background-color: #141e27;
  border: none;
  border-radius: 3px;
  height: 3em;
  width: 60%;
  color: #fff;
  box-shadow: inset 6px 6px 6px #0c0f11, inset -6px -6px 6px #252f38;
}

button {
  background-color: #f54620;
  box-shadow: inset 6px 6px 6px #c7391a, inset -6px -6px 6px #ee6445;
  cursor: pointer;
}

.result {
  height: 2em;
  width: 70%;
  border-radius: 10px;
  background-color: #141e27;
  color: #ffff;
  font-size: 23px;
  text-align: center;
  margin: auto;
  margin-top: 1.5em;
  padding: 1em;
}

@media screen and (max-width: 768px) {
  body {
    box-sizing: border-box;
    padding: 0;
    margin: 0;
    background-color: #1f313b;
  }

  .container {
    width: 70%;
    position: relative;
    height: 55em;
    margin: auto;
    margin-top: 2em;
    border-radius: 10px;
    box-shadow: 14px 14px 20px #141e27, -14px -14px 20px #121314;
  }
  .preface {
    width: 100%;
    height: 20em;
    background-color: #141e27;
    color: #fff;
    border-radius: 10px 10px 0 0;
    text-align: center;
  }

  .text {
    margin-top: 6em;
  }

  form {
    background-color: #eaedf2;
    width: 100%;
    height: 35em;
    border-radius: 0 0 10px 10px;
    text-align: center;
    margin: auto;
  }

  .weight,
  .height,
  .gender {
    margin-top: 2em;
  }

  button {
    margin-top: 5em;
  }

  label {
    font-size: 1.5em;
  }

  .result {
    height: 1em;
    width: 70%;
    border-radius: 10px;
    background-color: #141e27;
    color: #ffff;
    font-size: 23px;
    text-align: center;
    margin: auto;
    margin-top: 1.5em;
    padding: 1em;
  }
}