how to add space between buttons

1<style>
2/* Added to highlight spacing */
3.is-grouped {   
4    display: inline-block;
5    background-color: yellow;
6}
7
8.is-grouped > .button:not(:last-child) {
9    margin-right: 10px;
10}
11</style>
12
13Spacing shown in yellow<br><br>
14
15<div class='is-grouped'>
16    <button class='button'>Save</button>
17    <button class='button'>Save As...</button>
18    <button class='button'>Delete</button>
19</div>

1<div class='myDiv'>
2    <button style='margin-right:16px'>Button 1</button>
3    <button style='margin-right:16px'>Button 2</button>
4    <button>Button 3</button>
5</div>
6

1.yourClass{margin-left:100px;}