#pdfShell {
    position: relative;
    height: 100%; 
}

#pdfToolbar {
    /*position: absolute;*/
    /*top: 0;*/
    /*left: 0;*/
    /*right: 0;*/ /* = width:100% relativ zu #pdfShell */
    /*z-index: 5;*/
    /*box-sizing: border-box;*/ /* bezieht Padding/Border in die Breite ein */
    border-bottom: 1px solid #ddd;
    padding-left: 10px;
    padding-right: 10px;
}

#pdfViewerContainer {
    position: absolute;
    left: 0;
    right: 0;
    top: 56px;
    bottom: 0;
    overflow: auto;
    background: #f2f3f5;
}

.pdf-highlight {
    position: absolute;
    background: rgba(255, 230, 0, .35);
    outline: 1px solid rgba(180, 150, 0, .6);
    border-radius: 2px;
    pointer-events: none; /* nicht anklickbar */
    mix-blend-mode: multiply; /* optional, wirkt schöner auf Text */
    z-index: 3;
}

.pdf-highlight--flash {
    animation: pdfHighlightFlash 350ms ease-out;
}

@keyframes pdfHighlightFlash {
    from {
        box-shadow: 0 0 0 3px rgba(255, 230, 0, .9);
    }

    to {
        box-shadow: 0 0 0 0 rgba(255, 230, 0, 0);
    }
}

.page .textLayer {
    z-index: 2;
}

.page .pdf-highlight {
    z-index: 3;
}