.book {
    .book-summary {
        font-family: @font-family-sans;

        position: absolute;
        top: 0px;
        left: -@sidebar-width;
        bottom: 0px;
        z-index: 1;

        width: @sidebar-width;
        color: @sidebar-color;
        background: @sidebar-background;
        border-right: @sidebar-border-right;

        .transition(left @sidebar-transition-duration ease);

        ul.summary {
            position: absolute;
            top: 0px;
            left: 0px;
            right: 0px;
            bottom: 0px;

            overflow-y: auto;

            list-style: none;
            margin: 0px;
            padding: 0px;

            .transition(top 0.5s ease);

            li {
                list-style: none;

                &.divider {
                    height: 1px;
                    margin: 7px 0;
                    overflow: hidden;
                    background: @sidebar-divider-color;
                }

                i.fa-check {
                    display: none;
                    position: absolute;
                    right: 9px;
                    top: 16px;
                    font-size: 9px;
                    color: @sidebar-icon-color;
                }

                &.done {
                    > a {
                        color: @sidebar-link-completed;
                        font-weight: @sidebar-link-completed-weight;

                        i {
                            display: inline;
                        }
                    }
                }

                a, span {
                    display: block;
                    padding: 10px 15px;
                    border-bottom: none;
                    color: @sidebar-link-color;
                    background: @sidebar-link-background;
                    text-overflow: ellipsis;
                    overflow: hidden;
                    white-space: nowrap;
                    position: relative;
                }

                span {
                    cursor: not-allowed;
                    .opacity(0.3);
                }

                &.active > a, a:hover {
                    color: @sidebar-link-hover-color;
                    background: @sidebar-link-hover-background;
                    text-decoration: none;
                }

                ul {
                    padding-left: @sidebar-nested-padding;
                }
            }
        }

        @media (max-width: @sidebar-breakpoint) {
            width: calc(~"100% - 60px");
            bottom: 0px;
            left: -100%;
        }
    }

    &.with-summary {
        .book-summary {
            left: 0px;
        }
    }

    &.without-animation {
        .book-summary {
            .transition(none) !important;
        }
    }
}