ol {
    list-style-type: none;
}

li {
    position: relative;
    margin: 0;
    padding-bottom: 1em;
    padding-left: 20px;
}

li:before {
    content: "";
    background-color: blue;
    position: absolute;
    bottom: 0;
    top: 0;
    left: 6px;
    width: 3px;
}

li:after {
    content: "";
    border-radius: 50%;
    background-color: blue;
    position: absolute;
    left: 0;
    height: 15px;
    width: 15px;
}