html{
    scroll-padding-top: 100px;
    background: #171717;
}

.reality-book{
    display: flex;
    flex-direction: column;
    height: auto;
    color: white;
}

.reality-book-header {
    position: sticky;
    top: 0px;
    border-bottom: solid 1px #39c;
    background: rgb(23, 23, 23);
    z-index: 1;
    
}

.reality-book-header .title{
    display: table-cell;
    vertical-align: middle;
    padding: 15px;
    font-size: 1.3em;
    font-weight: bold;
    color: #39c;
}

.reality-book-header .search-area{
    width: 100%;
    max-width: 800px;
}

@media only screen and (max-width: 900px) {
    .reality-book-body-companion{
        display: none;
    }

    .external-links{
        display: none;
    }
}

.reality-book-body-companion{
    max-width: 240px;
}

.book-body-content{
    width: 100%;
    max-width: 800px;
    padding: 30px;
    padding-bottom: 150px;
}

.book-body-content img{
    max-width: 100%;
}


.book-body-content figure{
    text-align: center;
}

.book-body-content figure img{
    max-width: 70%;
}

.book-body-content figure figcaption{
    color: #39c;
    font-style: italic;
}
.book-body-content a{
    color: #39c;
    font-style: italic;
}
.book-body-content blockquote {
    border-left: 1px solid #39c;
    padding-left: 15px;
    font-style: italic;
    color: #a5a5a5;
}

.book-body-content table{
    margin: 0 auto;
}

.book-body-content td, .book-body-content th{
    border: 1px solid #39c;
    padding: 5px;
    text-align: center;
}

.reality-book-header a{
    color: #39c;
    padding: 15px;
}

.reality-content{
     display: flex;
     justify-content: center;
     padding: 0 15px;
     background: rgb(23, 23, 23);
}

.sticky{
    position: -webkit-sticky;
    position: sticky;
}
.top-50{
    top: 100px;
}


.companion-group{
    border-left: solid 2px #39c;
    padding-left: 24px;
}

.companion-group ~ .companion-group{
    margin-top: 20px;
}

.companion-group .btn{
    color: #a5a5a5;
    padding: 7px 0;
    cursor: pointer;
    display: block;
}

.companion-group .btn:hover {
    color: #39c;
}

.companion-group .btn.lv-H3 {
    padding-left: 15px;
}

.reality-book-summary ul.summary{
    margin: 0;
    padding: 0;
    list-style: none;
}

.reality-book-summary li.header {
    margin-top: 15px;
    padding: 10px 0;
    color: #39c;
}

.reality-book-summary a  {
    color: white;
    padding: 10px 15px;
    display: block;
}

.note {
    background-color: #39c;
    padding: 15px 30px;
    margin-right: 0;
    border-radius: 5px;
}

.note .title{
    padding-bottom: 15px;
    font-size: 1.3em;
}

.reality-book-summary a:hover {
    color: #39c;
}

.reality-book-summary li.active{
    background: rgba(51, 153, 204, 0.747);
}

.attribution{
    border-top: 1px solid #39c;
    padding: 15px;
}

.external-links a{
    color: #39c;
    padding: 15px;
    display: inline-block;
}

.flex{
    display:flex;
}
.flex.column{
    flex-direction: column;
}
.flex.row{
    flex-direction: row;
}
.noshrink{
    flex-shrink: 0;
}

.align-vertical {
    align-items: center;
}

.fill{
    height: 100%;
}

.center
{
    justify-content: center;
    text-align: center;
    align-items: center;
}

.youtube .caption{
    padding: 3px;
    color: #39c;
    font-style: italic;
}