.container { background-color: white; padding: 20px; ...
  .container { background-color: #fff; padding: 0px; ...
  .calculator { background-color: #ffffff; padding: 20px; ...
  .container { max-width: 1000px; margin: 0px auto; ...
  .container { width: 100%; margin: 0 auto; ...
  .container { width: 100%; max-width: 1000px; ...
  .calculator-container { background-color: #fff; padding: 30px; ...
  .container { background-color: #ffffff; padding: 20px; ...
  .container { width: 100%; margin: 0 auto; ...
  .container { max-width: 1000px; margin: auto; ...