body {
  font-size: 30px;
  
  color: red
}

 
h1{
  color: red;
  background-color: blue
  
}


p {
  color: yellow;
        font-family: arial, helvetica, sans-serif;          
    font-size: 70px;
}

a {
    color: blue;
}



















px (such as font-size: 12px) is the unit for pixels.
em (such as font-size: 2em) is the unit for the calculated size of a font. So “2em”, for example, is two times the current font size.
pt (such as font-size: 12pt) is the unit for points, for measurements typically in printed media.
% (such as width: 80%) is the unit for… wait for it… percentages.
Other units include pc (picas), cm (centimeters), mm (millimeters) and in (inches).

When a value is zero, you do not need to state a unit. For example, if you wanted to specify no border, it would be border: 0.