.dropdown-ajuda {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    width: 100%;
    display: block;
}
.dropdown-ajuda.show {
    max-height: 300px; 
}
.dropdown-conteudo {
    background: #fff;
    margin-top: -1px;
    padding: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    width: 100%;
    border-top: none;
}