border hide when click on button css code example

Example 1: html button remove border on click

.x-btn:focus, .button:focus, [type="submit"]:focus {
   outline: none;
}

Example 2: button remove border if click

<style>
input[type="button"]
{
    width:120px;
    height:60px;
    margin-left:35px;
    display:block;
    background-color:gray;
    color:white;
    border: none;
    outline:none;
}
</style>