Bootstrap navbar dropdown list hides behind html select option

Question

The problem is that I have a select option list in my body just below the bootstrap navbar, and the problem occur when I open select list and the hover over navbar to open its dropdwon, I have tried this solution but it didn't work for me.

.select-style {
    width: 100%;
    height: 40px;
    padding-left: 10px;
    background-image: url(/getmedia/f5d6e976-be64-4f97-b0bf-b4bb2c9ddf15/Dropdown.aspx);
    background-repeat: no-repeat;
    background-size: 12px;
    background-position: 96% center;
}
.select-style {
    border: 1px solid #ececec;
    font-size: 15px;
    font-family: arialRegular;
}

Answer 1

 .select-style { z-index:initial; } 

Answer 2

您必须给navbar父类z-index多个选择，并尝试以减号givr z-index进行选择