#lista li {
    cursor: pointer;
    padding: 10px;
    margin-bottom: 10px;
    transition: background 0.3s;
}

#lista li:hover { background: #f5f5f5; }

#lista .arrow {
    width: 23px;
    height: 14px;
}

#lista .texto {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.5s ease, opacity 0.5s ease;
    margin-top: 10px;
    color: #333;
    font-size: 0.9em;
    line-height: 1.35em;
}

#lista li.activo .texto {
    max-height: 200px; /* ajusta según contenido */
    opacity: 1;
}