HTML

input text size

<style> 
	#txtbox {
    font-size: 18pt;
    height: 42px;
    width : 300px;
}
</style>

<input type="text" id="txtbox">

change font size of input text html

<style>
#my_input{
	font-size:15px;  
}
</style>

<input id='my_input'>