html code position button code example

Example 1: html center button

button{
    /*Change the width as much as you like, but make sure 
    margin-left and margin-right + width = 100%*/
    width:50%;
    margin-left:25%;
    margin-right:25%;
}

Example 2: how to change the position of a button in css

#mainbutton {
  position: relative;
  bottom: 30px;
}