Reply To: Slider widget area on homepage: how to make responsive like Home Feature areas

It appears the problem is the width that was added in your custom css to the .slider .wrap –

.slider .wrap {
    margin: 0 auto;
    margin-bottom: -7px;
    padding: 0;
    width: 1140px;
    overflow: hidden;
}

If you remove that, then it should work