I have several designs that need to use the same html.(I can change the CSS file though.)
How can I use the display utility classes for an element by id in the CSS file?

Here is a code pen example. <https://codepen.io/warrenkc/pen/QPVpVR>

```
#wide {
    /* twitter-bootstrap display utility class */ 
    .d-lg-none
}
#small{
    /* twitter-bootstrap display utility class */ 
    .d-none d-lg-block
}

```