How to change the " Main Menu" letter to be lowercase ?

Main menu letters defaut is uppercase, I want to change to be only the first letter is uppercase, I click and inspect the main menu style in the page, when I made some changes with text-transform to be : none or lowercase, I see some changes, but when I coppied the code and paste it in the theme setting/custom css, I made the change but it did’t work. below is the code I used:

.wd-nav-main>li>a, .wd-nav-secondary>li>a {
text-transform: none;