Reply To: How to remove thin grey row from below slyder

take a look around line 1168 in your css and remove the bottom margin –

.slider .wrap {
    margin: 0 auto 20px;
    padding: 0;
    width: 1140px;
}

Change the 20px to 0 like this –

.slider .wrap {
    margin: 0 auto 0;
    padding: 0;
    width: 1140px;
}