/* The export viewer builds its tool in the browser after the page loads (viewer.js un-hides #viewer-app). Keep the tool's place while it is hidden, so the text below it
   does not jump when it appears (layout shift): about the height of the first screen of the tool, 357 px on wide screens and 460 px on phones. */
#viewer-app[hidden]{display:block!important;visibility:hidden;min-height:357px}
@media (max-width:640px){#viewer-app[hidden]{min-height:460px}}