my browser doesnt scale my website even though the website works on tablet/phone

so basiclly im a uni student and i got marked dow because when the teacher rescaled the the browser, the website didnt rescale with it, even though the website recaled correctly on a tablet and phone. can any one tell why this could be? im using this in the html/php file

<meta name="viewport" content="width=device-width, initial-scale=1.0" />

and this in the css (different px for different screens)

@media only screen and (max-device-width: 1366px) and (min-device-width: 1025px) {