<div class="container">
  <div class="todo_list">
    <ul>
      <li><!--TO DO ITEM START-->
        <label>
          <input type="checkbox" class="hidden_real_check"/>
          <div class="todo_element">
            
            <span class="customized_ckeck">
              <span class="checkbox">
                <span class='internal_one'></span>
                <span class='internal_two'></span>
              </span>
            </span>
            <span class="element_title">Something important to do</span>
          </div>
        </label>
      </li><!--TO DO ITEM END-->
      
      <li><!--TO DO ITEM START-->
        <label>
          <input type="checkbox" checked class="hidden_real_check"/>
          <div class="todo_element">
            
            <span class="customized_ckeck">
              <span class="checkbox">
                <span class='internal_one'></span>
                <span class='internal_two'></span>
              </span>
            </span>
            <span class="element_title">Another something</span>
          </div>
        </label>
      </li><!--TO DO ITEM END-->
      
      <li><!--TO DO ITEM START-->
        <label>
          <input type="checkbox" class="hidden_real_check"/>
          <div class="todo_element">
            
            <span class="customized_ckeck">
              <span class="checkbox">
                <span class='internal_one'></span>
                <span class='internal_two'></span>
              </span>
            </span>
            <span class="element_title">Get a new pencil</span>
          </div>
        </label>
      </li><!--TO DO ITEM END-->
      
      <li><!--TO DO ITEM START-->
        <label>
          <input type="checkbox" class="hidden_real_check"/>
          <div class="todo_element">
            
            <span class="customized_ckeck">
              <span class="checkbox">
                <span class='internal_one'></span>
                <span class='internal_two'></span>
              </span>
            </span>
            <span class="element_title">Finish some task today</span>
          </div>
        </label>
      </li><!--TO DO ITEM END-->
    </ul>
  </div>
</div>

body{
  background: #f5f5f5;
}

.container{
  width: 100%;
  max-width: 300px;
  margin: 50px auto;
}

.todo_list{
  background: #fff;
  box-shadow: 0 0 27px #ccc;
}

.todo_list ul {
  list-style: none;
  padding: 0;
}

.todo_list ul li label{
  display: block;
  position: relative;
  padding: 0 10px;
}

.hidden_real_check{
  width: 100%;
  height: 100%;
  opacity:0;
  position: absolute;
}

.todo_element{
  border-bottom: 1px solid #ddd;
  padding: 10px 0;
}
.todo_list ul li:last-child .todo_element{
  border-bottom: none;
}

.customized_ckeck{
  display: inline-flex;
  width: 15%;
  height: 2em;
  align-items: center;
  justify-content: flex-end;
}
.element_title{
  display: inline-block;
  width: 85%;
  height: 2em;
  float: right;
  font-family: 'Open Sans', sans-serif;
  line-height: 2em;
  position : relative;
  color:#333;
  letter-spacing:1px;
}

.element_title:after{
  content: '';
  position: absolute;
  top :50%;
  height: 2px;
  width: 0;
  background-image: linear-gradient(90deg, #4facfe, #00f2fe);
  left: -5px;
  z-index: 2;
  transition: 0.3s;
}

.element_title:before{
  content: '';
  position: absolute;
  top :0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255,255,255,0.7);
  z-index: 1;
  transition: 0.3s;
  opacity:0;
}

.todo_list ul li label .hidden_real_check:checked + .todo_element .element_title::after {width: 90%;}
.todo_list ul li label .hidden_real_check:checked + .todo_element .element_title::before {opacity: 1;}
.checkbox {
  width: 25px;
  height: 25px;
  margin-right:5px;
  position: relative;
  transition: 0.1s;
  transition-delay: 0.3s;
}
.checkbox span[class*='internal_'] {
  position: absolute;
  top: 0; right: 0; left: 0; bottom: 0;
}
.checkbox:after{
  content: '✔';
  position: absolute;
  top:0; left: 2px; right: -2px; bottom: 0;
  display: flex;
  align-items: center;
  justify-content:center;
  color: #4facfe;
  transform: scale(0);
  transition: 0.4s;
}
.checkbox:before{
  content: '';
  position: absolute;
  top:0; left: 2px; right: -2px; bottom: 0;
  border-radius:50%;
  border : 5px dotted #4facfe;
  transform: scale(0) rotate(0);
  transition: 0.5s;
  transition-delay: 0.3s;
}
.checkbox span[class*='internal_']::after, .checkbox span[class*='internal_']::before{
  content: '';
  position: absolute;
  top: 0px; left: 2px;
  height: 100%;
  width: 100%;
  border-radius:50%;
  border: 2px solid transparent;
  transform: rotate(45deg);
  box-sizing: border-box;
}
.checkbox span.internal_one::after{
  border-top-color:#4facfe !important;
  transition: 0.4s;
}
.checkbox span.internal_one::before{
  border-left-color:#4facfe !important;
  transition: 0.3s;
  transition-delay:0.1s;
}
.checkbox span.internal_two::after{
  border-bottom-color:#4facfe !important;
  transition: 0.2s;
  transition-delay:0.2s;
}
.checkbox span.internal_two::before{
  border-right-color:#4facfe !important;
  transition: 0.1s;
  transition-delay:0.3s;
}
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox .internal_one:after{
  transform: rotate(-225deg);
}
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox .internal_one:before{
  transform: rotate(-135deg);
}
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox .internal_two:after{
  transform: rotate(-45deg);
}
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox span[class*='internal_']:after,
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox span[class*='internal_']:before{
  border-color: transparent !important;
}
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox:after {
  transform : scale(1);
}
.todo_list ul li label .hidden_real_check:checked + .todo_element .checkbox:before {
  transform : scale(1.6) rotate(-90deg);
  opacity: 0;
}