/* Adapted for Bootstrap 4 from https://www.bootply.com/SzXin8KDZJ. */
.timeline {
    list-style: none;
    padding: 10px 0 10px;
    position: relative;

    &:before {
        top: 0;
        bottom: 0;
        position: absolute;
        content: " ";
        width: 3px;
        background-color: #eeeeee;
        left: 50%;
        margin-left: -1.5px;

    }

    li {
        margin-bottom: 10px;
        position: relative;

        &:before {
            content: " ";
            display: table;
        }

        &:after {
            content: " ";
            display: table;
            clear: both;
        }

        .card {
            width: 47%;
            float: left;
            border: 1px solid #d4d4d4;
            border-radius: 2px;
            padding: 10px;
            position: relative;
            -webkit-box-shadow: 0 1px 6px rgba(0, 0, 0, 0.175);
            box-shadow: 0 1px 6px rgba(0, 0, 0, 0.175);

            &:before {
                position: absolute;
                top: 26px;
                right: -15px;
                display: inline-block;
                border-top: 15px solid transparent;
                border-left: 15px solid #ccc;
                border-right: 0 solid #ccc;
                border-bottom: 15px solid transparent;
                content: " ";
            }

            &:after {
                position: absolute;
                top: 27px;
                right: -14px;
                display: inline-block;
                border-top: 14px solid transparent;
                border-left: 14px solid #fff;
                border-right: 0 solid #fff;
                border-bottom: 14px solid transparent;
                content: " ";
            }
        }

        &.timeline-inverted {
            .card {
                float: right;

                &:before {
                    border-left-width: 0;
                    border-right-width: 15px;
                    left: -15px;
                    right: auto;
                }

                &:after {
                    border-left-width: 0;
                    border-right-width: 14px;
                    left: -14px;
                    right: auto;
                }
            }
        }

        .timeline-badge {
            color: #fff;
            width: 50px;
            height: 50px;
            line-height: 50px;
            font-size: 1.4em;
            text-align: center;
            position: absolute;
            top: 16px;
            left: 50%;
            margin-left: -25px;
            background-color: #999999;
            z-index: 100;
            border-radius: 50%;
        }

        .timeline-badge.arrow {
            color: #fff;
            width: 50px;
            height: 50px;
            line-height: 50px;
            font-size: 1.4em;
            text-align: center;
            position: absolute;
            top: 26px;
            left: 50%;
            margin-left: -25px;
            background-color: #999999;
            z-index: 100;
            border-radius: 50%;
        }
    }
}

@media (max-width: 767px) {
    ul.timeline:before {
        left: 40px;
    }

    ul.timeline > li > .card {
        width: calc(100% - 90px);
        width: -moz-calc(100% - 90px);
        width: -webkit-calc(100% - 90px);
    }

    ul.timeline > li > .timeline-badge {
        left: 15px;
        margin-left: 0;
        top: 16px;
    }

    ul.timeline > li > .card {
        float: right;
    }

    ul.timeline > li > .card:before {
        border-left-width: 0;
        border-right-width: 15px;
        left: -15px;
        right: auto;
    }

    ul.timeline > li > .card:after {
        border-left-width: 0;
        border-right-width: 14px;
        left: -14px;
        right: auto;
    }
}