Bootstrap을 기반으로 한 수직 아코디언 애니메이션 효과

<div class="container">
      <div class="row">
          <div class="col-md-offset-3 col-md-6">
              <div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
                  <div class="panel panel-default">
                      <div class="panel-heading" role="tab" id="headingOne">
                          <h4 class="panel-title">
                              <a role="button" data-toggle="collapse" data-parent="#accordion"
                                href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
                                  SECTION 1
                              </a>
                          </h4>
                      </div>
                      <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel"
                            aria-labelledby="headingOne">
                          <div class="panel-body">
                              <p>......</p>
                          </div>
                      </div>
                  </div>
                  ......
              </div>
          </div>
      </div>
  </div>

a:hover,a:focus{
    text-decoration: none;
    outline: none;
}
#accordion .panel{
    border: none;
    box-shadow: none;
    border-radius: 0;
    margin-bottom: -5px;
}
#accordion .panel-heading{
    padding: 0;
    border-radius: 0;
    border: none;
    text-align: center;
}
#accordion .panel-title a{
    display: block;
    padding: 25px 30px;
    font-size: 16px;
    font-weight: bold;
    color: #fff;
    background: #333;
    border-bottom: 1px solid #4a4a4a;
    position: relative;
    transition: all 0.5s ease 0s;
}
#accordion .panel-title a:hover{
    background: #4a4a4a;
}
#accordion .panel-title a:after,
#accordion .panel-title a.collapsed:after{
    content: "\f067";
    font-family: FontAwesome;
    font-size: 15px;
    font-weight: 200;
    position: absolute;
    top: 25px;
    left: 15px;
    transform: rotate(135deg);
    transition: all 0.5s ease 0s;
}
#accordion .panel-title a.collapsed:after{
    transform: rotate(0deg);
}
#accordion .panel-body{
    background: #167ea0;
    padding: 0 0 0 40px;
    border: none;
    position: relative;
}
#accordion .panel-body p{
    font-size: 14px;
    color: #fff;
    line-height: 25px;
    background: #3296b7;
    padding: 30px;
    margin: 0;
}
#accordion .panel-collapse .panel-body p{
    opacity: 0;
    transform: scale(0.9);
    transition: all 0.5s ease-in-out 0s;
}
#accordion .panel-collapse.in .panel-body p{
    opacity: 1;
    transform: scale(1);
}