Использование нескольких значений для метода iQuery .css() выдает ошибку: «отсутствует)». Однако его не хватает

jQuery($ => {

  const createElement = () => {

    const tagName = $('#element').val();
    
    return $(`<${tagName}/>`, {
      appendTo: '#layout',
      text: `This is a ${tagName}`,
      css: {
        backgroundColor: "blue",
        height: "100px"
      },
    });

  }

  $('#create').on('click', createElement);

});

<section id = "form">
  <label>
    Please select type of container to add
    <select id = "element">
      <option value = "div">&ltdiv&gt</option>
      <option value = "p">&ltp&gt</option>
      <option value = "section">&ltsection&gt</option>
    </select>
  </label>
  <button id = "create">Create Container</button>
</section>
<div id = "layout"></div>

<script src = "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

$(document).ready(function() {

  // event-handler to create new element
  function createContainer() {

    // variables store values from <select> element
    var elementType = $('select').val();

    // string containing markup for use with .append()
    var elementTypeStr = $(` <${elementType}> This is a ${elementType} </${elementType}> `);
    // this throws error, while setting single style doesn't
    $('#layout_demo').append(elementTypeStr);
    elementTypeStr.css({
      "background-color": " blue",
      "height": "100px"
    });

  } // end createContainer()

  // ---------------------------- event handlers ---------------------

  $('#btn').click(createContainer);
  // button to delete latest element or selected element

}); // end ready

<script src = "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<section id = "form">
  <!-- select element --->
  <label for = "container"> Please select type of container to add</label>
  <select id = "container">
    <option value = "div"> &ltdiv&gt </option>
    <option value = "p"> &ltp&gt </option>
    <option value = "section"> &ltsection&gt </option>

  </select>
  <!-- Seperate container to hold now elements -->

  <button id = "btn"> Create Container </button>
</section>

<div id = "layout_demo">



</div>