body {
    font-family: sans-serif;
    font-size: 15px;
}
.tree{
    margin-left: 30%;
    width: 70%;
}
.tree ul {
    position: relative;
    padding: 1em 0;
    white-space: nowrap;
    margin: 0 auto;
    text-align: center;
}
.tree ul::after {
    content: '';
    display: table;
    clear: both;
    }

.tree li {
    display:  block;
    vertical-align: top;
    text-align: center;
    list-style-type: none;
    position: relative;
    padding: 1em 0 0 0;
    }

.tree li::before,
.tree li::after {
    content: '';
    position: absolute;
    top: 0;
    right: 50%;
    height: 1em;
}

.tree li::after {
    right: auto;
    left: 50%;
    border-left: 1px solid #ccc;
}

.tree li:only-child::after,
.tree li:only-child::before {
    display: none;
}

.tree li:only-child {
    padding-top: 0;
}

.tree li:first-child::before,
.tree li:last-child::after {
    border: 0 none;
}

.tree li:last-child::before {
    border-right: 1px solid #ccc;
    border-radius: 0 5px 0 0;
}

.tree li:first-child::after {
    border-radius: 5px 0 0 0;
}

.tree ul ul::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    border-left: 1px solid #ccc;
    width: 0;
    height: 1em;
}

.tree li div.process-group {
    border: 1px solid #ccc;
    padding: .5em .75em;
    text-decoration: none;
    border-radius: 5px;
    color: #333;
    position: relative;
    top: 1px;
}

    .tree li div.process-group:hover,
    .tree li div.process-group:hover + ul li div.process-group {
        background: #2b6ccc;
        border: 1px solid #2b6ccc;
    }

    .tree li div:hover + ul li::after,
    .tree li div:hover + ul li::before,
    .tree li div:hover + ul::before,
    .tree li div:hover + ul ul::before {
        border-color: #2b6ccc;
    }