.dropzone{border:2px dashed #cccccc;border-radius:4px;padding:20px;text-align:center;cursor:pointer;transition:border-color .2s ease-in-out,background-color .2s ease-in-out}.dropzone:hover{border-color:#3f51b5}.dropzone.active{border-color:#3f51b5;background-color:#e3f2fd}