.timeline {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
}

.timeline::after {
    content: "";
    position: absolute;
    width: 6px;
    background-color: #353535;
    top: 0px;
    bottom: 0px;
    left: 50%;
    margin-left: -3px;
}

.tl-container {
    padding: 10px 40px;
    position: relative;
    background-color: inherit;
    width: 50%;
    box-sizing: border-box;
}

.tl-container::after {
    content: "";
    position: absolute;
    width: 25px;
    height: 25px;
    right: -17px;
    background-color: #4fa679;
    border: 4px solid #d0d0d0;
    top: 15px;
    border-radius: 50%;
    z-index: 1;
}

.tl-left {
    left: 0px;
}

.tl-right {
    left: 50%;
}

.tl-left::before {
    content: " ";
    height: 0px;
    position: absolute;
    top: 22px;
    width: 0;
    z-index: 1;
    right: 30px;
    border: medium solid #e4e4e4;
    border-width: 10px 0 10px 10px;
    border-color: transparent transparent transparent #e4e4e4;
}

.tl-right::before {
    content: " ";
    height: 0px;
    position: absolute;
    top: 22px;
    width: 0;
    z-index: 1;
    left: 30px;
    border: medium solid #e4e4e4;
    border-width: 10px 10px 10px 0;
    border-color: transparent #e4e4e4 transparent transparent;
}

.tl-right::after {
    left: -16px;
}

.tl-content {
    border: 1px solid #e4e4e4;    
    padding: 10px 20px;
    background-color: white;
    position: relative;
    border-radius: 6px;
    cursor: pointer;
}

.tl-content:hover {
    background-color: #e4f4f4;
    transition: 0.3s;
}

.tl-body, .tl-section {
    margin-top: 10px;
}

@media screen and (max-width: 600px) {

    .timeline::after {
        left: 31px;
    }

    .tl-container {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }

    .tl-container::before {
        left: 60px;
        border: medium solid white;
        border-width: 10px 10px 10px 0px;
        border-color: transparent white transparent transparent;
    }

    .tl-left::after, .tl-right::after {
        left: 15px;
    }

    .tl-right {
        left: 0%;
    }

}