MediaWiki:Vector.css

/* HIDE all sidebar blocks ONLY for anonymous users */
body:not(.mw-user-loggedin) #mw-panel .portal {
    display: none !important;
}

/* SHOW the logo for anonymous users */
body:not(.mw-user-loggedin) #p-logo {
    display: block !important;
}

/* Ensure logo image is visible */
body:not(.mw-user-loggedin) #p-logo a,
body:not(.mw-user-loggedin) #p-logo a img {
    display: block !important;
    visibility: visible !important;
}

/* SHOW personal tools (login link) */
body:not(.mw-user-loggedin) #p-personal {
    display: block !important;
}

/* PRESERVE EMPTY SIDEBAR SPACE BELOW LOGO for anonymous users */
body:not(.mw-user-loggedin) #mw-panel::after {
    content: '';
    display: block;
    height: 400px; /* Adjust as needed */
    background: transparent;
}

/* 🟢 ENSURE all sidebar blocks remain visible for logged-in users */
body.mw-user-loggedin #mw-panel .portal {
    display: block !important;
}