How to solve this z-index bug?

Question

How to get this issue solved, The tooltip i am integrating is getting its overlay over the next div. i have tried all the possible values of the z- index but it doesn't resolve the issue. i am attaching my code with the respective screenshot

<span class="tooltip">?<span class="tooltiptext arrow_box">*Because we’ve got 50% money back guarantee for clients, we keep the remaining of the money as deposit, in case a client is not happy and wants to get a chargeback.</span></span>


.tooltip .tooltiptext {
    visibility: hidden;
    width: 380px;
    background-color: #4f577d;
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 15px 0;
    right: 50%;
    text-align: center;
    position: absolute;
    z-index: 1;
    top: -136px;
    margin: 0 auto;
    font-size: 15px;
    padding: 10px 20px;
    text-align: center;
}

/* Css for next div */

.custom-sec-4{
    z-index: 2;
}

.custom-sec-4 p{
    z-index: -1;
}