body {
  margin-left: 4%; margin-right: 4%;
  color: black; background: white;
  text-align: left;
}

.reference {
  color: #800000;
}

  H1 { 
 text-align: center;
 color: black;
 font:  200% sans-serif;
}

H2 { 
 text-align: center;
 color: black;
 font:  150% sans-serif;
}

H3 { 
 text-align: center;
 color: black;
 font:  125% sans-serif;
}

H4 { 
 text-align: center;
 color: black;
 font:  110% sans-serif;
}

P {
 text-align: left;
 color: black;

}