Template:Fmbox/styles.css

/* Cell sizes for ambox/tmbox/imbox/cmbox/ombox/fmbox/dmbox message boxes */
th.mbox-text, td.mbox-text {   /* The message body cell(s) */
	padding: 0.25em 0.9em;     /* 0.9em left/right */
}
td.mbox-image {                /* The left image cell */
	padding: 2px 0 2px 0.9em;  /* 0.9em left, 0px right */
}
td.mbox-imageright {           /* The right image cell */
	padding: 2px 0.9em 2px 0;  /* 0px left, 0.9em right */
}