p

@use postcss-media-minmax;

body {
    display: grid;
    place-items: center;
    min-height: 100vh;
    font-size: 30px;
    transition: font-size 0.3s;
}

@media (480px <= width <= 768px) {
    body {
        background-color: red;
        font-size: 80px;
        color: #fff;
    }
}

// Just display width of viewport for easy to understand this demo
function getWindowWidth() {
    return (document.querySelector("p").textContent = window.innerWidth);
}
getWindowWidth();
window.addEventListener("resize", getWindowWidth);