how to edit html paragraph size and boldness in css code example

Example 1: 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*/

Example 2: html make text bold

<b> Bold Text </b>