.app{overflow:auto;border:none;-webkit-overflow-scrolling:touch}.scrollbar{margin:0 auto}::-webkit-scrollbar-track-piece{background-color:#f8f8f8}::-webkit-scrollbar{width:5px;height:9px}::-webkit-scrollbar-thumb{background-color:#ddd;background-clip:padding-box;min-height:28px}::-webkit-scrollbar-thumb:hover{background-color:#bbb}