MediaWiki:Common.css

/* CSS placed here will be applied to all skins */
#p-logo a {
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
}
#p-logo a img {
    width: 100%;
    height: auto;
    max-width: 135px; /* Set max width as per your layout */
    max-height: 135px; /* Set max height if needed */
    object-fit: contain; /* Scales the logo to fit the space */
}
body.special-page #p-logo a img,
body.login-page #p-logo a img {
    width: 100%;
    max-width: 135px;
    max-height: 135px;
    object-fit: contain;
    object-position: center;
}