how to increase boldness in css code example

Example 1: change the weight of a bold font css

p {  
  font-weight: normal;
} 
a {  
  font-weight: bold;
}  
p.thick {  
  font-weight: 780;
}

Example 2: font. to be thinner css

font-weight: 200; /*100 200 300 400 500 600 700 800 900 
					Defines from thin to thick characters. 
					400 is the same as normal, 
					and 700 is the same as bold*/