Off-canvas sub-menu spacing on mobile

Hello,

I'm having trouble adjusting the spacing on the sub-menu items on the mobile off-canvas view. I have added the following CSS from another post but it doesn't seem to do anything:

/* off-canvas sub-menu spacing*/
@media(min-width: 769px) {
.main-navigation .main-nav ul li.menu-item-has-children:before {
content: '';
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 70px; /* height of nav plus space below */
}

.main-navigation .main-nav ul ul {
margin-top: 10px;
}
}

You can see a pic of the current spacing here: https://cloud.moonraker.ai/pHNrwbn

I am trying to expand the distance of the sub-menu items to match the main items. Your help is appreciated!