body {
  background: #E7E9EB;
}

#ifDiv > iframe {
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  border: none;
  background: #fff;
}

#editorDiv {
  resize: horizontal;
}

#editorDiv, #ifDiv {
  background-color: #fff;
  position: relative;
  border: 2px solid lightgrey;
  overflow: hidden;
  padding: 6px;
}

#editorDiv textarea {
  padding: 0;
  border: none;
  box-shadow: none;
}

#editorDiv[min-width~="700px"]{
  background: red;
}