align button inside button code example

Example 1: horizontaly center button css

button {
    margin:0 auto;
    display:block;
}

Example 2: 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%;
}