jq滚动条插件perfect-scrollbar悬浮时，背景颜色透明样式

.ps:hover>.ps__scrollbar-y-rail:hover {
    background: transparent
}

.ps.ps--in-scrolling.ps--y>.ps__scrollbar-y-rail,
.ps:hover.ps--in-scrolling.ps--y>.ps__scrollbar-y-rail {
    background: transparent
}

.ps:hover>.ps__scrollbar-x-rail:hover {
    background: transparent
}

.ps.ps--in-scrolling.ps--x>.ps__scrollbar-x-rail,
.ps:hover.ps--in-scrolling.ps--x>.ps__scrollbar-x-rail {
    background: transparent
}