.fa_hline_left {
    width: 50%;
  margin-left:0;margin-right:auto;
    height: 1px;
    background: #ddd;
    margin: 30px auto 15px 0;
    max-width: 450px;
    position: relative;
}
.fa_hline_left span {
    height: 3px;
    top: -1px;
    position: absolute;
  
    width: 50px;
    background: #086ab5;
    animation: fa_sumline_ani_left 5s linear infinite alternate;
}
@keyframes fa_sumline_ani_left{
0%{ width:20px;}
50%{ width:100px;}
100%{ width:20px;}
}

@-webkit-keyframes fa_sumline_ani_left /*Safari and Chrome*/
{
0%{ width:20px;}
50%{ width:100px;}
100%{ width:20px;}
}