Hello,

Please remove all the custom CSS provided earlier and those you added by your own.

Please add this code to the Theme Settings > Custom CSS > Global:

body .widget_shopping_cart .buttons .btn-cart{
background-color:#444444!important;
color:#ffffff!important;
}
body .widget_shopping_cart .buttons .checkout{
color:#ffffff!important;
background-color:#444444!important;
}
body .widget_shopping_cart .buttons .btn-cart:hover{
background-color:rgba(201,201,201,0.35)!important;
color:#ffffff!important;
}
body .widget_shopping_cart .buttons .checkout:hover{
background-color:rgba(201,201,201,0.35)!important;
color:#ffffff!important;
} 
body .widget_shopping_cart .amount{
color:#ffffff;
}
body .widget_shopping_cart .woocommerce-mini-cart__total strong{
color:#ffffff;
}
body .dropdown-cart .widget_shopping_cart .empty {
    color: #ffffff!important;
}

Please provide your site admin access so that I could give you the code for My account drop-down.

Best Regards