style.css

.btn, .f_btn
{
  font-family: helvetica;
  color: #FFFFFF;
  display: inline-block;
  margin:3px;
  border-radius: 2px;
  cursor: pointer;
  transition: all .2s;
}

.btn.shadow{box-shadow: 0px 1px 3px rgba(0,0,0,0.55);}
.btn.shadow:hover{box-shadow: 0px 2px 9px rgba(0,0,0,0.55);}

.btn.bevel{box-shadow: 0px 1px 3px rgba(0,0,0,0.55);}
.btn.bevel:hover{box-shadow: 0px 2px 9px rgba(0,0,0,0.55);}

.btn.r, .f_btn.r
{
  background-color: hsla(0, 100%, 46%, 1);
}
.btn.r:hover
{
  background-color: hsla(0, 100%, 66%, 1);
}
.btn.g, .f_btn.g
{
  background-color: hsla(152, 100%, 38%, 1);
}
.btn.g:hover
{
  background-color: hsla(152, 100%, 40%, 1);
}
.btn.b, .f_btn.b
{
  background-color: hsla(204, 100%, 38%, 1);
}
.btn.b:hover
{
  background-color: hsla(204, 100%, 44%, 1);
}

.btn.s,.f_btn.s
{
  padding: 8px 16px;
  font-size: 15px;
}
.btn.m,.f_btn.m
{
  padding: 12px 24px;
  font-size: 18px;
}
.btn.l,.f_btn.l
{
  padding: 20px 32px;
  font-size: 27px;
}
.f_btn
{
  transform: translateY(-3px);
}

.f_btn.r{
  box-shadow: 0px 3px 0px hsla(0, 100%, 38%, 1);
}
.f_btn.g{
  box-shadow: 0px 3px 0px hsla(152, 100%, 30%, 1);
}
.f_btn.b{
  box-shadow: 0px 3px 0px hsla(204, 100%, 30%, 1);
}

.f_btn.r:active{
  box-shadow: 0px 0px 0px hsla(0, 100%, 38%, 1);
}
.f_btn.g:active{
  box-shadow: 0px 0px 0px hsla(152, 100%, 30%, 1);
}
.f_btn.b:active{
  box-shadow: 0px 0px 0px hsla(204, 100%, 30%, 1);
}

.f_btn:active
{
  transform: translateY(0);
}