PHP conditions depending on window width (media queries?)

PHP conditions depending on window width (media queries?)

I have a responsive website and I need some PHP conditions depending on
the windows width (or media queries).
Example:
if ($window_width > 1400px) {
echo 'Your window is wider than 1400px';
}
elseif ($window_width > 1000px) AND ($window_width < 1399px) {
echo 'Your window is between 1000px and 1399px';
}
else {
echo 'Your window is narrower than 1000px.';
}
Thanks for your help! I think I need some JS to detect the window width
and combine it with PHP.