How to import css by screen size

screenSize.md

index.html

<link media="(max-width:600px)" href="../../assets/css/style-small.css" rel="stylesheet">
<link media="(min-width:601px)" href="../../assets/css/style-large.css" rel="stylesheet">

style-small.css

@media (max-width:600px) {
    .project-header {
        font-size: 1.2em;
    }
}

style-large.css

@media (min-width: 601px) {
    .project-header {
        font-size: 2em;
    }
}