"Menu" Button Disappearing When Child Theme Changed

I have been working on making the button, which appears to take the place of the top navbar menu, appear flatter. Therefore, I have worked to remove the text-shadow, linear gradient, etc. However, every time I make changes to what I believe to be the appropriate code, the button disappears.

Here is the original code that I found that I believe needs the necessary changes.

.navbar .btn-navbar {
    background-color: #006394;
    background-image: linear-gradient(to bottom, #0077B3, #004466);
    background-repeat: repeat-x;
    border-color: rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);
    box-shadow: 0 1px 0 rgba(255, 255, 255, 0.1) inset, 0 1px 0 rgba(255, 255, 255, 0.075);
    color: white;
    display: none;
    float: right;
    margin-left: 5px;
    margin-right: 5px;
    padding: 7px 10px;
    text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.25);
}

I am trying to change the above to

.navbar .btn-navbar {
    background-color: #0067C6;
    background-image: none;
    background-repeat: repeat-x;
    border-color: none;
    box-shadow: none;
    color: white;
    display: none;
    float: right;
    margin-left: 5px;
    margin-right: 5px;
    padding: 7px 10px;
    text-shadow: none;
}

Thanks for any help that the community could provide, y’all have been amazing thus far.