Pode remover esses 2 estilos acima, adicione esses no lugar:
.menu-mobile__button {
top: 0 !important;
display: flex;
flex-direction: column-reverse;
height: 50px;
}
.menu-mobile__button:after {
content: 'MENU';
font-family: Verdana, Geneva, sans-serif;
font-size: 9px;
font-weight: 600;
}