body{ background-color: #F3F3F3;
  font-size:100%; 
} 
p { color: black; line-height: 1.5em; text-align:left; font-size:.60 em; font-family: Franklin Gothic Book, Book Antiqua, "Trebuchet MS", Garamond, Georgia, arial, sans-serif; margin-left:2cm} 
p1 { color: black; line-height: 1.5em; text-align:left; font-size:1.25 em; font-family: Franklin Gothic Book, Book Antiqua, "Trebuchet MS", Garamond, Georgia, arial, sans-serif; margin-left:2cm} 
p2 { color: black; line-height: 1.5em; text-align:left; font-size:.60 em; font-family: Franklin Gothic Book, Book Antiqua, "Trebuchet MS", Garamond, Georgia, arial, sans-serif; margin-left:2cm} 
p.ex1 {margin: 0 250px 0 93px}
p.ex2 {margin: 0 100px 0 93px}
p.ex3 {margin: 0 250px 0 93px}

<p class="ex1">
p.margin
{
margin-right:0px;
margin-left:95px;
}
p2.margin
{
margin-right:200px;
margin-left:10px;
}
h1{ color: #1d309e; font-weight: bold; margin-left:2cm; text-align:left; font-size:35px; font-family: Franklin Gothic Book, Book Antiqua, "Trebuchet MS", Garamond, Georgia, tahoma, verdana, helvetica, arial, sans-serif}
h2{ color: #1d309e; font-weight: bold; margin-left: 95px; text-align:left; font-size:25px; font-family: Franklin Gothic Book, Book Antiqua, "Trebuchet MS", Garamond, Georgia, tahoma, verdana, helvetica, arial, sans-serif}
<!--
.tab { margin-left: 120px; }
-->
p1.margin
{
margin-left:150px;
}
@media screen and (max-width: 40em) {
    body {
        font-size:90%;
    }
}
@media screen and (max-width: 30em) {
    body {
        font-size:80%;
    }
@media screen and (max-width: 20em) {
    body {
        font-size:70%;
    }
@media screen and (max-width: 10em) {
    body {
        font-size:60%;
    }
}