gitlab-org--gitlab-foss/app/assets/stylesheets/sections/editor.scss

.file-editor {
  
  #editor{
    height: 500px;
    width: 90%;
    position: relative;
    margin-bottom: 20px;
  }
  textarea{
    display: block;
    width: 40%;
    margin: 10px 0 10px 0;
  }
}