electron-demo.js/style.css

body > div {
  padding: 1em;
}
body > div > h3 {
  margin-top: 0em;
  text-align: center;
}

.drag-n-drop {
  background: rgb(200, 200, 255);
  border: 1px dotted black;
  min-height: 150px;
}

.notify button {
  width:40%;
}