Since you're using these arrows for a toggle switch you may want to consider creating these arrows with an html element using the following styles instead of unicode characters.
.upparrow {
height: 0;
width: 0;
border: 4px solid transparent;
border-bottom-color: #000;
}
.downarrow {
height: 0;
width: 0;
border: 4px solid transparent;
border-top-color: #000;
}