.timeline {
    position: relative;
    list-style: none;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    width: 1px;
    background: #dedede ;
    left: 50%;
    margin-left: -10px;
}

.timeline li {
    position: relative;
    opacity: 0;
    transition: opacity .25s ease-in-out;
}

.timeline li .dot {
    width: 12px;
    height: 12px;
    margin: 0 0 0 -15px;
    text-align: center;
    left: 50%;
    top: 0; 
    position: absolute;
    border-radius: 10px;
    background: #999;
}

.timeline li:nth-child(odd) .content {
    margin: 0 0 0 53%;
}

.timeline li:nth-child(even) .content {
    position: relative;
    width: 44%;
    text-align: right;
}

@media screen and (max-width: 47.2em) {
	.timeline:before {
		left: 1px;
	}

    .timeline li .dot {
        left: 1px;
    }

    .timeline li:nth-child(odd) .content,
    .timeline li:nth-child(even) .content {
        width: 100%;
        position: relative;
        padding: 0px 10px;
        text-align: left;
        margin: 0px;
        right: 0px;
    }
}

.timeline li.discover-li {
    opacity: 1;

}