.container { max-width: 1000px; ...

  .container { width: 100%; ...

  .container { margin-top: 100px; ...

  .calculator { background-color: #fff; ...

  .container { max-width: 1000px; margin: 0 auto; ...

  .calculator { background-color: white; ...

  section { margin: 20px; ...

  .container { background-color: white; ...

  .container { width: 100%; ...

  .calculator-container { background-color: white; padding: 30px; ...