Hwo to align button in center of page in html css? 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 do you center buttons in css

<div style="text-align:center;">
    <button>button1</button>
    <button>button2</button>
</div>