#post-table-content li.toc-list-item a:before{ color: #686868; content: counter(item, disclosure-closed) ' '; } .vertical { aspect-ratio: 9/16; max-width: 400px; margin: auto; } .bounce-button { animation: bounce 2s infinite;  } @keyframes bounce { 0%, 20%, 50%, 80%, 100% { transform: translateY(0);  } 40% { transform: translateY(-20px);  } 60% { transform: translateY(-10px);  } }