[name='open-children'] {
    position: absolute;
    visibility: hidden;
    width: 0;
    height: 0;
    margin: 0;
}

.acc_wrapper {
    overflow: hidden;
    max-height: 0;
    transition: all .15s 0s linear;
}

.acc_wrapper li {
    transition: all .25s .15s linear;
    transform: translateX(100%);
}

.example-list {
    margin-top: 40px;
}

.example-list li {
    position: relative;
    margin-bottom: 20px;
    padding: 0;
}

.example-list .acc_wrapper ul {
    position: relative;
}

.example-list .acc_wrapper ul::before {
    position: absolute;
    top: 0;
    display: inline-block;
    width: 1px;
    height: calc(100% - 60px);
    content: '';
    transition: transform .15s 0s linear;
    transform: scaleY(0);
    transform-origin: top center;
    background-color: #ccc;
}

.example-list .acc_wrapper li {
    margin-left: 30px;
}

.example-list .acc_wrapper li::before {
    position: absolute;
    top: 0;
    left: -30px;
    display: inline-block;
    width: 30px;
    height: 30px;
    content: '';
    border-bottom: solid 1px #ccc;
    border-left: solid 1px #ccc;
}

.example-list .link_pdf, .example-list label {
    display: block;
    padding: 1em;
    cursor: pointer;
    text-decoration: none;
    border: solid 1px #ccc;
    border-radius: 5px;
}

.example-list .link_pdf:hover, .example-list label:hover {
    color: inherit;
    background-color: #ffe0e0;
}

.example-list ul {
    margin-left: 30px;
    padding-top: 20px;
}

/*selected*/

[name='open-children']:checked+label+.acc_wrapper {
    max-height: 200vh;
}

[name='open-children']:checked+label+.acc_wrapper>ul::before {
    transform: scaleY(1.02);
}

[name='open-children']:checked+label+.acc_wrapper>ul>li {
    transform: translateX(0);
}