w3c viewport tutorial code example
Example 1: viewport meta tag
<meta name="viewport" content="width=device-width, initial-scale=1">
Example 2: viewport meta tags
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="viewport" content="width=device-width, initial-scale=1.0" />