.timeline {
    list-style: none;
    padding: 20px 0 20px;
    position: relative;
    margin-top: 70px;
}

ul.timeline:before {
    display: none;
}

ul .timeline {
    max-width: 100%;
}

.timeline:before {
    top: 0;
    bottom: 0;
    position: absolute;
    content: "";
    width: 3px;
    background-color: #d9d9d9;
    margin-left: -1.5px;
    left: 20px;
}

.timeline > li {
    position: relative;
    padding-left: 55px;
    margin-top: -30px;
}

.timeline > li:after, .timeline > li:after {
    content: "";
    display: table;
    clear: both;
}

.timeline > li .panel {
    float: left;
    border-radius: 10px;
    overflow: hidden;
    position: relative;
    text-align: left;
    top: -40px;
    background-color: var(--bg-primary);
    padding: 25px;
}

.timeline > li > .panel > p {
    padding: 0 20px 10px;
    color: var(--text-secondary);
}

.timeline > li .panel summary {
    display: block;
    outline: none;
    padding: 20px;
    margin-bottom: 0;
    transition: all 600ms cubic-bezier(0.23, 1, 0.32, 1);
    transition-property: margin;
    font-weight: 600;
    font-size: 28px;
}

.timeline > li > .icon {
    color: #d9d9d9;
    width: 20px;
    height: 20px;
    line-height: 50px;
    font-size: 2.5em;
    text-align: center;
    position: absolute;
    left: 20px;
    margin-left: -10px;
    z-index: 2;
    border-radius: 50%;
    background-color: var(--bg-primary);
    border: 4px solid var(--theme-color-highlight);
    margin-top: 20px;
}



.timeline > li > .icon:before {
    content: "";
}

@media (min-width: 800px) {
    .timeline:before {
        left: 50%;
    }

    .timeline > li {
        padding-left: 0;
    }

    .timeline > li .panel {
        width: 50%;
    }

    .timeline > li:not(:nth-child(even)) {
        padding-right: 90px;
    }

    .timeline > li:nth-child(even) {
        padding-left: 90px;
    }

    .timeline > li:nth-child(even) > :nth-child(even) {
        float: right;
    }

    .timeline > li > .icon {
        left: 50%;
    }
}