@media(-webkit-min-device-pixel-ratio:2),(min-resolution:192dpi){.timeslot .task .arrow{background:url(../img/timeline-left-arrow@2x.png) no-repeat;background-size:100%}.timeslot.alt .task .arrow{background:url(../img/timeline-right-arrow@2x.png) no-repeat;background-size:100%}ul.chat li.left .message .arrow{background:url(../img/chat-left@2x.png) no-repeat 0 0;background-size:100%}ul.chat li.right .message .arrow{background:url(../img/chat-right@2x.png) no-repeat 0 0;background-size:100%}}