.iconfont.icon-luogu::before {
    content: '';
    display: inline-block;
    
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    width: 1.2em; 
    height: 1.2em;
    vertical-align: -0.15em; 
    
    background-image: url('/img/luogu.png'); 
  }
  
  html[data-user-color-scheme="light"] .iconfont.icon-luogu::before {
    background-image: url('/img/luogu-dark.png'); 
  }