伪选择器：使用js或jquery添加宽度之后

Question

.main-timeline10 .timeline:nth-child(1) .timeline-inner:after {
  background: #58b25e;
  width: 50px;
}

1. 我使用上面的样式为div添加宽度。
2. 我想使用js或jquery向这种特定样式添加宽度。
3. 由于它具有伪选择器:after，是否可以为此添加宽度？
4. 现在只需使用通用选择器就可以了
5. 如何使用js或jquery以编程方式更改此宽度
6. 使用公共选择器$(".main-timeline10.timeline:nth-child(1).timeline-inner:after").css("width","100%")，但没有用

Update

根据下面的建议，我检查了link是否为接受的答案。

1. 已添加课程
2. 已添加属性
3. 但是样式没有实现

遇到错误

//$('.main-timeline10.timeline:nth-child(1).timeline-inner').attr("style","width:100%");

$('.main-timeline10 .timeline-inner').addClass('changewidth').attr('data-width','100%');

.changewidth:after {
		width: attr(data-width);
	}

a {
  text-decoration: none
}

h4 {
  text-align: center;
  margin: 30px 0;
  color: #444
}

.main-timeline10:after,
.main-timeline10:before {
  content: "";
  display: block;
  width: 100%;
  clear: both
}

.main-timeline10 .timeline {
  padding: 0;
  display: -webkit-inline-box;
}

.main-timeline10 {
  display: flex;
  min-height: 750px;
}

.main-timeline10 .col-md-3 {
  -ms-flex: 0 0 20%;
  flex: 0 0 20%;
  max-width: 30%;
  /* max-width: 24%; */
  align-self: flex-end;
  display: flex;
}

.main-timeline10 .timeline-inner {
  text-align: center;
  margin: 0px 0px 17px 30px;
  /* margin: 20px 20px 35px 35px; */
  position: relative;
}

.main-timeline10 .timeline:nth-child(1) .timeline-inner:after {
  background: #58b25e;
  width: 50px;
}

.main-timeline10 .timeline:nth-child(2) .timeline-inner:after {
  background: #9f84c4;
  width: 0;
}

.main-timeline10 .timeline:nth-child(3) .timeline-inner:after {
  background: #f35958;
  width: 0;
}

.main-timeline10 .timeline:nth-child(4) .timeline-inner:after {
  background: #e67e49;
  width: 0;
}

.main-timeline10 .timeline .timeline-inner:after {
  content: "";
  background: #555;
}

.main-timeline10 .timeline-inner:after {
  /* .col-md-3.col-sm-6.timeline{	 */
  /* width: 120%; */
  width: 100%;
  height: 6px;
  /* background: #58b25e;#555; */
  position: absolute;
  bottom: 0;
  left: 10%
}

.main-timeline10 .timeline:last-child .timeline-inner:after {
  width: 0
}

.main-timeline10 .tier {
  background: #58b25e;
  padding: 5px 30px;
  border-radius: 30px 0;
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  z-index: 1;
  position: relative
}

.main-timeline10 .tier:after,
.main-timeline10 .tier:before {
  position: absolute;
  top: -19px;
  content: ""
}

.main-timeline10 .tier:before {
  right: 0;
  border: 10px solid transparent;
  border-bottom: 10px solid #58b25e;
  border-right: 10px solid #58b25e
}

.main-timeline10 .tier:after {
  width: 25px;
  height: 19px;
  border-radius: 0 0 20px;
  background: #fff;
  right: 1px
}

.main-timeline10 .timeline-content {
  padding: 10px 10px 30px;
  border-left: 3px solid #58b25e;
  position: relative
}

.main-timeline10 .timeline-content:before {
  content: "";
  position: absolute;
  top: 0;
  left: -1px;
  border: 10px solid transparent;
  border-top: 10px solid #58b25e;
  border-left: 10px solid #58b25e
}

.main-timeline10 .timeline-content:after {
  content: "";
  width: 25px;
  height: 19px;
  border-radius: 20px 0 0;
  background: #fff;
  position: absolute;
  top: 0;
  left: 0
}

.main-timeline10 .post {
  /* font-size: 26px; */
  font-size: 12px;
  color: #333
}

.main-timeline10 .description {
  font-size: 14px;
  color: #333
}

.main-timeline10 .timeline-icon {
  width: 70px;
  height: 70px;
  line-height: 65px;
  border-radius: 50%;
  border: 5px solid #58b25e;
  background: #fff;
  font-size: 30px;
  color: #555;
  z-index: 1;
  position: absolute;
  bottom: -35px;
  left: -35px
}

.main-timeline10 .col-md-3.timeline:nth-child(1n) .timeline-content {
  min-height: 20%;
}

.main-timeline10 .col-md-3.timeline:nth-child(2n) .timeline-content {
  min-height: 380px;
  max-height: 440px;
}

.main-timeline10 .col-md-3.timeline:nth-child(3n) .timeline-content {
  min-height: 460px;
  max-height: 520px;
}

.main-timeline10 .col-md-3.timeline:nth-child(4n) .timeline-content {
  min-height: 520px;
  max-height: 580px;
}

.main-timeline10 .col-md-3.timeline:nth-child(5n) .timeline-content {
  min-height: 600px;
}

.timeline-content {
  overflow: auto;
}

.main-timeline10 .timeline:nth-child(2n) .tier {
  background: #9f84c4
}

.main-timeline10 .timeline:nth-child(2n) .tier:before {
  border-bottom-color: #9f84c4;
  border-right-color: #9f84c4
}

.main-timeline10 .timeline:nth-child(2n) .timeline-content {
  border-left-color: #9f84c4
}

.main-timeline10 .timeline:nth-child(2n) .timeline-content:before {
  border-top-color: #9f84c4;
  border-left-color: #9f84c4
}

.main-timeline10 .timeline:nth-child(2n) .timeline-icon {
  border-color: #9f84c4
}

.main-timeline10 .timeline:nth-child(3n) .tier {
  background: #f35958
}

.main-timeline10 .timeline:nth-child(3n) .tier:before {
  border-bottom-color: #f35958;
  border-right-color: #f35958
}

.main-timeline10 .timeline:nth-child(3n) .timeline-content {
  border-left-color: #f35958
}

.main-timeline10 .timeline:nth-child(3n) .timeline-content:before {
  border-top-color: #f35958;
  border-left-color: #f35958
}

.main-timeline10 .timeline:nth-child(3n) .timeline-icon {
  border-color: #f35958
}

.main-timeline10 .timeline:nth-child(4n) .tier {
  background: #e67e49
}

.main-timeline10 .timeline:nth-child(4n) .tier:before {
  border-bottom-color: #e67e49;
  border-right-color: #e67e49
}

.main-timeline10 .timeline:nth-child(4n) .timeline-content {
  border-left-color: #e67e49
}

.main-timeline10 .timeline:nth-child(4n) .timeline-content:before {
  border-top-color: #e67e49;
  border-left-color: #e67e49
}

.main-timeline10 .timeline:nth-child(4n) .timeline-icon {
  border-color: #e67e49
}

.main-timeline10 .timeline:nth-child(5n) .tier {
  background: #275959
}

.main-timeline10 .timeline:nth-child(5n) .tier:before {
  border-bottom-color: #275959;
  border-right-color: #275959
}

.main-timeline10 .timeline:nth-child(5n) .timeline-content {
  border-left-color: #275959
}

.main-timeline10 .timeline:nth-child(5n) .timeline-content:before {
  border-top-color: #275959;
  border-left-color: #275959
}

.main-timeline10 .timeline:nth-child(5n) .timeline-icon {
  border-color: #275959
}

.timeline-inner {
  width: 100%
}

@media only screen and (max-width:990px) {
  .main-timeline10 .timeline-inner:after {
    width: 110%
  }
  .main-timeline10 .timeline .timeline-inner:after {
    width: 0
  }
}

@media only screen and (max-width:767px) {
  .main-timeline10 .timeline {
    margin-bottom: 50px
  }
  .main-timeline10 .timeline-inner:after,
  .main-timeline10 .timeline .timeline-inner:after {
    width: 100%;
    height: 3px;
    left: 0
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.2.0/css/all.css" integrity="sha384-hWVjflwFxL6sNzntih27bfxkr27PmbbK/iSvJ+a4+0owXq79v+lsFkW54bOGbiDQ" crossorigin="anonymous">
<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<div class="container">
  <h4>Timeline Style : Demo-10</h4>
  <div class="row">
    <div class="main-timeline10">
      <div class="col-md-3 col-sm-6 timeline">
        <div class="timeline-inner">
          <div class="tier">Rank 1</div>
          <div class="timeline-content">

          </div>
          <div class="timeline-icon">
            <i class="fas fa-project-diagram"></i>
          </div>



        </div>

      </div>
      <div class="col-md-3 col-sm-6 timeline">
        <div class="timeline-inner">
          <div class="tier">Rank 2</div>
          <div class="timeline-content">


          </div>
          <div class="timeline-icon">
            <i class="fas fa-microchip"></i>
          </div>
        </div>
      </div>
      <div class="col-md-3 col-sm-6 timeline">
        <div class="timeline-inner">
          <div class="tier">Rank 3</div>
          <div class="timeline-content">


          </div>
          <div class="timeline-icon">
            <i class="fas fa-sitemap"></i>
          </div>
        </div>
      </div>
      <div class="col-md-3 col-sm-6 timeline">
        <div class="timeline-inner">
          <div class="tier">Rank 4</div>
          <div class="timeline-content">


          </div>
          <div class="timeline-icon">
            <i class="fas fa-laptop-code"></i>
          </div>
        </div>
      </div>


      <div class="col-md-3 col-sm-6 timeline">
        <div class="timeline-inner">
          <img src="http://localhost/ilearn/assets/images/Star.gif" class="" alt="avatar" height="80" width="80">
          <div class="tier">Final</div>
          <div class="timeline-content">

          </div>
          <div class="timeline-icon">
            <i class="fas fa-trophy"></i>
          </div>
        </div>
      </div>
    </div>
  </div>
</div>
<hr>