.CodeMirror-dialog {
  position: relative;
}
 
.CodeMirror-dialog > div {
  position: absolute;
  top: 0; left: 0; right: 0;
  background: white;
  border-bottom: 1px solid #eee;
  z-index: 15;
  padding: .1em .8em;
  overflow: hidden;
  color: #333;
}
 
.CodeMirror-dialog input {
  border: none;
  outline: none;
  background: transparent;
  width: 20em;
  color: inherit;
  font-family: monospace;
}