fsxxs - font-size: xx-small
fsxs - font-size: x-small
fss - font-size: small
fssr - font-size: smaller
fsm - font-size: medium
fslr - font-size: larger
fsl - font-size: large
fsxl - font-size: x-large
fsxxl - font-size: xx-large
<div class="fsxxs">fsxxs - font-size: xx-small</div>
<div class="fsxs">fsxs - font-size: x-small</div>
<div class="fss">fss - font-size: small</div>
<div class="fssr">fssr - font-size: smaller</div>
<div class="fsm">fsm - font-size: medium</div>
<div class="fslr">fslr - font-size: larger</div>
<div class="fsl">fsl - font-size: large</div>
<div class="fsxl">fsxl - font-size: x-large</div>
<div class="fsxxl">fsxxl - font-size: xx-large</div>