Open the index to the examples.
This is a small collection of simple pages that can be tested on various devices. Each page has its own stand-alone CSS file for easy copying.
The idea is to provide files that can be easily copied and modified by beginners who are just learning how to use media queries.
Note that EVERY example has the viewport meta tag in the HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title> Responsive Web Design Examples </title>
<link rel="stylesheet" href="css/main.css">
</head>This meta tag is essential for responsive HTML pages.
Reference: Using media queries