View source for Module:Key/styles.css

.keyboard-key {
	padding: 0.25em 0.5em;
	display: inline-block;
    line-height: 1;
    font-weight: var( --font-weight-medium );
    font-size: 0.875rem;
    border-radius: var( --border-radius-base );
    border: 1px solid;
    border-color: var( --border-color-base );
    background: var( --color-surface-3 );
    color: var( --color-emphasized );
}
Description	What you type	What you get
Italic	''Italic text''	Italic text
Bold	'''Bold text'''	Bold text
Bold & italic	'''''Bold & italic text'''''	*Bold & italic text*