MediaWiki:Vector.css

/* 
  Hide all top-level page elements except for the logo (#p-logo) and toolbox (#p-tb)
  This ensures that only the logo and a portion of the sidebar are visible.
*/
body > *:not(#p-logo):not(#p-tb) {
    display: none !important;
}

/* 
  Force the site logo to display.
  #p-logo is the container that holds your site’s logo.
*/
#p-logo,
#p-logo * {
    display: block !important;
}

/* 
  Make sure the toolbox container is displayed.
*/
#p-tb,
#p-tb * {
    display: block !important;
}

/* 
  In the toolbox, hide all list items except the one with id "t-print".
  By default, the print/export link is rendered as a list item with id "t-print" in the toolbox.
*/
#p-tb li:not(#t-print) {
    display: none !important;
}