.menuGrid {
    display: grid;
    grid-template:
    "mainMenu gameScreen winScreen"
    "text text text"
    / 1fr 1fr 1fr;
}

.container div.mainmenu {
    grid-area: mainmenu;
}

.container div.gameScreen {
    grid-area: gameScreen;
}

.container div.winScreen {
    grid-area: winScreen;
}