body { padding-bottom: 130px; }

.pre { background:rgba(228,228,228,0.5); }
.sel { background:rgba(0,255,0,0.5); }
.not { background:rgba(255,0,0,0.5); }
.nex { background:rgba(255,255,0,0.5); }

.hidden { visibility:hidden }

footer {
   position: fixed;
   height: 140px;
   bottom: 0;
   width: 100%;
}


.card:hover { background : beige; }

.float-right { float: right; }
.float-left { float: left; }

.yellow { color: #ffc107; }