uppy/examples/playground/static/css/style.css

.UppyDragDrop {
  width: 300px;
  /*height: 200px;*/
  text-align: center;
  /*background-color: #f6fbfb;*/
  padding: 100px 10px;
}

/* http://tympanus.net/codrops/2015/09/15/styling-customizing-file-inputs-smart-way/ */
.UppyDragDrop-input {
  width: 0.1px;
	height: 0.1px;
	opacity: 0;
	overflow: hidden;
	position: absolute;
	z-index: -1;
}

.UppyDragDrop.is-dragdrop-supported {
  border: 2px dashed;
  border-color: #ccc;
}

.UppyDragDrop-label {
  cursor: pointer;
}

.UppyDragDrop-dragText {
  display: none;
}

.is-dragdrop-supported .UppyDragDrop-dragText {
  display: inline;
}

.UppyDragDrop.is-dragover {
  border-color: #d2ecea;
  background-color: #dbf5f3;
}