styles.css

.react-resizable {
  position: relative;
}
.react-resizable-handle.react-draggable {
  position: absolute;
  width: 20px;
  height: 20px;
  bottom: 0;
  right: 0;
  background: url('data:image/svg+xml;base64,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');
  background-position: bottom right;
  padding: 0 3px 3px 0;
  background-repeat: no-repeat;
  background-origin: content-box;
  box-sizing: border-box;
  cursor: se-resize;
  /* Since this handle is absolutely positioned, we don't want the
     draggable transforms to actually move it */
  transform: none !important;
  -webkit-transform: none !important;
  -ms-transform: none !important;
  -o-transform: none !important;
  -moz-transform: none !important;
}