body {
    margin: 0;
    font-family: sans-serif;
}


#sidebar {
    position: fixed;
    left: 0;
    width: 60px;
    height: 100%; /* fill calc(100vh - 60px) remaining height */
    overflow-y: auto;
    background: transparent;
    border-right: 1px solid #ccc;
    padding: 10px 5px;
    box-sizing: border-box;
    z-index: 5;
}

#nav-left,
#nav-right {
    flex-shrink: 0;
}

#nav-center {
    flex: 1;
    overflow-x: auto; /* visible */
    overflow-y: visible; /* allow vertical overflow for tooltips */
    white-space: nowrap; /* scroll? do normal otherwise, then word-break: break-word; */
    text-align: center;
    position: relative;
    z-index: 5;
}
#pageInfo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: -100px; /* vertical spacing between page numbers */
    /*overflow: visible; /* important */
    padding: 0;
    margin: 0;
}

.page-link {
    display: inline-block;
    padding: 2px 4px;
    margin: 0;
    text-decoration: none;
    color: black;
    font-size: 20px;
}

iframe {
    position: absolute;
    top: 5px;
    left: 60px;
    width: calc(100vw - 60px);
    height: 100%; /* full viewport calc(100vh - 60px) minus height of nav */
    border: none;
}

.tooltip-wrapper {
    position: relative;
    /* display: inline-block; */
    display: inline-block; /* or try inline; */
    /* margin: 0 5px; */
}

.tooltip {
    visibility: hidden;
    background-color: #333;
    /* color: #fff; */
    text-align: center;
    border-radius: 4px;
    padding: 5px 8px;
    font-size: 12px;
    position: absolute;
    z-index: 9999; /* or try 1; ? */
    left: 120%; /* place above */
    /*top: 120%; /* show below instead of above */
    transform: translateY(-50%);
    opacity: 0;
    transition: opacity 0.2s;
    white-space: nowrap;
    pointer-events: none;
}

.tooltip::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    border-width: 5px;
    border-style: solid;
    /*border-color: #333 transparent transparent transparent; /* triangle pointing up */
    border-color: transparent transparent transparent #333; /* triangle pointing  */
}

.tooltip-wrapper:hover .tooltip {
    visibility: visible;
    opacity: 1;
}
#tooltip-layer {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 10000;
}

.global-tooltip {
    position: absolute;
    transform: translateY(-50%);
    background: #333;
    color: #fff;
    padding: 6px 10px;
    border-radius: 4px;
    font-size: 12px;
    white-space: nowrap;
    z-index: 10000;
}