.panel-container,
.panel-container-vertical {
    position: relative;
}

.panel-container {
    display: flex;
    flex-direction: row;
    overflow: hidden;
    padding-right: 15px;
    /* avoid browser level touch actions */
    touch-action: none;
}

.panel-left {
    flex: 0 0 auto;
    /* only manually resize */
    width: 40%;
    white-space: nowrap;
}

.splitter {
    flex: 0 0 auto;
    width: 10px;
    background: url(../img/vsizegrip.png) center center no-repeat #ededed;
    min-height: 200px;
    cursor: col-resize;
}

.panel-right {
    flex: 1 1 auto;
    /* resizable */
    padding: 0 0 0 10px;
    width: 100%;
    min-height: 200px;
    min-width: 200px;
    background: #f8f8f8;
}

/* vertical panel */
.panel-container-vertical {
    display: flex;
    flex-direction: column;
    height: 500px;
    border: 1px solid silver;
    overflow: hidden;
}

.panel-top {
    flex: 0 0 auto;
    /* only manually resize */
    padding: 10px;
    height: 150px;
    width: 100%;
    white-space: nowrap;
    background: #838383;
    color: white;
}

.splitter-horizontal {
    flex: 0 0 auto;
    height: 10px;
    background: url(../img/hsizegrip.png) center center no-repeat #535353;
    cursor: row-resize;
}

.panel-bottom {
    flex: 1 1 auto;
    /* resizable */
    padding: 10px;
    min-height: 200px;
    background: #eee;
}

#resize-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0);
    /* Fully transparent */
    display: none;
    /* Hidden by default */
    z-index: 1000;
    /* Ensure it’s on top of the PDF */
}