::-webkit-scrollbar {
    width: 0;
    height: 0;
}

.bar_wrapper {
    position: relative;
    z-index: 1;
    overflow: hidden;
    margin: 1px auto;
}
.bar_scroller {
    display: block;
    padding: 0;
    height: 100%;
}
.bar_scroller::-moz-focus-inner {
    padding: 10px; 
    border: 10px solid red;
}
.bar_scroller:focus {
    outline: none;
}
.scroller__bar {
    position: absolute;
    z-index: 1;
    display: none;
    width: 8px;
    border-radius: 4px;
    background: #987;
    opacity: .9;
    -webkit-transition: width .2s linear;
    transition: width .2s linear;
}
.scroller__bar:hover,
.scroller__bar._dragging {
    opacity: 1;
}
.scroller__bar {
    display: block;
}

.bar_container {
    overflow: hidden;
}