Background color and left pane

The plugin is great! I use it on Elementor.

Please how to set container/page background color on desktop/mobile?

I tried custom CSS:

.pdfViewer div,
.viewerContainer div,
.mainContainer div {
background color: white !important;
body-bg-color: rgba(255, 255, 255, 1);
}

…without success.

Also, how to avoid that the left pane is initially open.

Thank you.