child css

  p:nth-child(2)
 	{     
 		background: red;
 	}/*Specify a background color for every <p> element that is the 
second child of its parent:*/
  
 p:nth-child(2)
 	{     
 		background: red;
 	}
  
 /* Selects the second <li> element in a list */
li:nth-child(2) { 
  color: lime;
}

/* Selects every fourth element
   among any group of siblings */
:nth-child(4n) {
  color: lime;
}
li:nth-child(even) { /* Selects only even elements */
    color: green;   
}:nth-child(3) { //the number is the child number you are targeting
	//styles here 
}tr:nth-child(even) {background: #CCC}
tr:nth-child(odd) {background: #FFF}