p { margin: 0 ;}

.c1 { font-size: xx-small ;}
.c2 { font-size: x-small ;}
.c3 { font-size: small ;}
.c4 { font-size: medium ;}
.c5 { font-size: large ;}
.c6 { font-size: x-large ;}++++++++
.c7 { font-size: xx-large }