set the size of a button code example

Example 1: button size html

<button style="height:40px; width:40px;">Press Me</button>

Example 2: how to set button width in javascript

var buttonShort = document.createElement("button");
buttonShort.innerHTML = "Generate Short Password";

var body = document.getElementsByTagName("body")[0];

buttonShort.style.width = '200px'; // setting the width to 200px
buttonShort.style.height = '200px'; // setting the height to 200px
buttonShort.style.background = 'teal'; // setting the background color to teal
buttonShort.style.color = 'white'; // setting the color to white
buttonShort.style.fontSize = '20px'; // setting the font size to 20px

body.appendChild(buttonShort);

buttonShort.addEventListener("click", function() {
  var newWindow = window.open();
  newWindow.document.write("The generated Password is: '" + short() + "'");
  newWindow.focus();
});