CSS Dropdown menu toggle issue

Question

I've been trying to make a website about north korea for a computer science project following this tutorial https://www.youtube.com/watch?v=FazgJVnrVuI&t=1406s at 23:21 he is able to make the text disappear i for some reason can't please help. CSS:

here@media screen and (max-width:960px) {
.navbar__container {
    display: flex;
    justify-content: space-between;
    height: 80px;
    z-index: 1;
    width: 100%;
    max-width: 1300px;
    padding: 0;
}
.navbar__menu{
    display: grid;
    grid-template-columns: auto;
    margin: 0;
    width: 100%;
    position: absolute;
    top: -1000px;
    opacity: 0;
    transition: all 0.5s ease;
    height: 50vh;
    z-index: -1;
}

}