.btn-app {
    background: #3b76a3;
    color: #fff;
}

    .btn-app:hover {
        border: 1px solid #3b76a3;
        background: #fff;
        color: #3b76a3;
        transition: background 0.5s;
    }

.selector {
    background: #3b76a3;
}

    .selector:hover {
        background: #2b5b80;
    }

    .selector:active {
        background: #1e405c !important;
    }