.tip {
position: fixed;
left: 50%;
bottom: 50%;
auto;
-webkit-transform: translateX(-50%);
-ms-transform: translateX(-50%);
transform: translateX(-50%);
background: rgba(0, 0, 0, 0.5);
z-index: 3000;
font-size: 0.8em;
color: #fff;
line-height: 1;
padding: 0.5em;
white-space: nowrap;
-webkit-border-radius: 0.25em;
-ms-border-radius: 0.25em;
border-radius: 0.25em
}