body,
html {
  margin: 0;
  background-color: #eee;
}
body {
  text-align: center;
}

.canvasWrapper {
  width: 1440px;
  height: 900px;
}
.qrcodewrapper {
  padding: 30px;
  display: block;
}

.flex {
  display: flex;
  justify-content: center;
  align-items: center;
}