Limit width and height of embedded gists.

limit-gist-box-size.css

/**
*   Limit embedded gist window size. Show scrollbars when necessary.
*   @link https://imelgrat.me/
*/

/* Limit width. Show scrollbars when exceeding width */
.gist {
   max-width:350px;
   overflow:auto;
}

/* Limit height. Show scrollbars when exceeding height */
.gist .blob-wrapper.data {
   max-height:300px;
   overflow:auto;
}