#rescalc{font-weight:700; padding 10px 15px; font-size:100%;}
.first_calc{color:#1976d2; font-size:150%; font-weight:700; cursor:pointer; width:100%; margin:10px 15px;}
.second_calc{display:none;width:100%; margin:10px 15px; padding-top:25px;}
.second_calc.active{display:block;}