There is a mobile version of the site (fully tires). registered the definition of the width of the device.

<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />

In iPhone 4s, the resolution is 640 × 960 pixels, and displays 320 × 480?

    1 answer 1

    browser to consider pixels based on the size of the device, rather than its real resolution. @media query rules should be written based on device pixels, not real resolution.