Как выровнять флажок рядом с текстом

.check {
  width: 30px;
  height: 30px;
  background-color: red;
  display: inline-block;
}
.text {
  display: inline-block;
  height: 30px;
  line-height: 30px;
  vertical-align: top;
  padding: 0 5px;
}
input[type = "checkbox"] {
  display: none;
}
input[type = "checkbox"]:checked + label {
  background-color: black;
}
input[type = "checkbox"]:checked ~ .text {
  background-color: #0f0;
  color: white;
  text-decoration: line-through;
}

<input type = "checkbox" id = "a" />
<label class = "check" for = "a"></label><div class = "text">Get shit done</div>

var toDoItems = [];
var i = 1;
var userInput;
var listElement;
var checkBox;

document.getElementById("addItem").onclick = function() {
  userInput = prompt("Enter your Todo: ")
  toDoItems.push(userInput);
  document.getElementById("item-list").insertAdjacentHTML('beforeend', stylePara());
}

function stylePara() {
  var html = '';
  
  html += '<label class = "container">';
  html +=   '<input type = "checkbox">';
  html +=   '<span class = "checkmark"></span>';
  html +=   '<span class = "checklabel">' + userInput + '</span>';
  html += '</label>';

  return html;
}

/* The container */

.container {
  width: 100%;
  margin-left: 40%;
  /*this is the general left margin*/
  display: block;
  position: relative;
  padding-left: 35px;
  margin-bottom: 12px;
  cursor: pointer;
  font-size: 22px;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}


/* Hide the browser's default checkbox */

.container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}


/* Create a custom checkbox */

.checkmark {
  position: absolute;
  top: -5px;
  left: 0;
  height: 35px;
  width: 35px;
  background-color: #eee;
}


/* On mouse-over, add a grey background color */

.container:hover input~.checkmark {
  background-color: #ccc;
}


/* When the checkbox is checked, add a green background */

.container input:checked~.checkmark {
  background-color: darkgreen;
}


/* label when unchecked */

.checklabel {
  background: red;
  color: white;
  padding: 5px 20px;
}


/* label when checked */

.container input:checked~.checklabel {
  text-decoration: line-through;
  background: green;
  color: white;
  padding: 5px 20px;
}


/* Create the checkmark/indicator (hidden when not checked) */

.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}


/* Show the checkmark when checked */

.container input:checked~.checkmark:after {
  display: block;
  top: 10px;
  left: 15px
}


/* Style the checkmark/indicator */

.container .checkmark:after {
  left: 9px;
  top: 5px;
  width: 5px;
  height: 10px;
  border: solid white;
  border-width: 0 3px 3px 0;
  -webkit-transform: rotate(45deg);
  -ms-transform: rotate(45deg);
  transform: rotate(45deg);
}

<h1>To do list</h1>
<button id = "addItem">Add item</button>
<div id = "item-list">
  <label class = "container">
    <input type = "checkbox" checked = "checked">
    <span class = "checkmark"></span>
    <span class = "checklabel">Example item</span>
  </label>
</div>

.item {
    align-items: center;
    display: flex;
}

/* Sample custom styles. */
.item p {
    background: red;
    color: white;
    font-size: 20px;
}

<div>
    <div class = "item">
        <input type = "checkbox">
        <p>Item 1</p>
    </div>
    <div class = "item">
        <input type = "checkbox">
        <p>Item 2</p>
    </div>
</div>