Check out example codes for "placeholder css". It will help you in understanding the concepts better.

Code Example 1

input::-webkit-input-placeholder {/* Chrome/Opera/Safari/Edge */
	/*styles here*/
}

input::-ms-input-placeholder { /* Microsoft Edge */
   /*styles here*/
}

input:-ms-input-placeholder {/* IE 10+ */
	/*styles here*/
}

input::-moz-placeholder {/* Firefox 19+ */
	opacity: 1; /*Firefox by default has an opacity object that usually is ideal to reset so it matches webkit*/
	/*styles here*/
}

input:-moz-placeholder {/* Firefox 18- */
	opacity: 1; /*Firefox by default has an opacity object that usually is ideal to reset so it matches webkit*/
	/*styles here*/
}

input::placeholder {
	/*styles here*/
}

Code Example 2

::-webkit-input-placeholder {color: pink;} /* Chrome/Opera/Safari */
::-moz-placeholder { color: pink;} /* Firefox 19+ */
:-ms-input-placeholder { color: pink;} /* IE 10+ */
:-moz-placeholder {color: pink;}  /* Firefox 18- */

Code Example 3

::placeholder { 
  /* Chrome, Firefox, Opera, Safari 10.1+ */
  color: red;
  opacity: 1; /* Firefox */
}

:-ms-input-placeholder { /* Internet 
  Explorer 10-11 */
  color: red;
}

::-ms-input-placeholder 
  { /* Microsoft Edge */
  color: red;
}

Code Example 4

input[type="text"]::placeholder {  
                  
                /* Firefox, Chrome, Opera */ 
                padding-left: 10px; 
            } 
/*Must include type="text" in HTML*/

Code Example 5

::placeholder

Code Example 6

-webkit-user-select: none; /* Safari */        
-moz-user-select: none; /* Firefox */
-ms-user-select: none; /* IE10+/Edge */
user-select: none; /* Standard */

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