[Screen orientation] #responsive

snippet.js

if (screen && screen.orientation !== null) {
  window.screen.orientation.onchange = () => { 
    switch (screen.orientation.type) {
  	  case "landscape-primary":
        console.log("That looks good.");
        break;
      case "landscape-secondary":
        console.log("Mmmh… the screen is upside down!");
        break;
      case "portrait-secondary":
      case "portrait-primary":
        console.log("Mmmh… you should rotate your device to landscape");
      break;
      default:
        console.log("The orientation API isn't supported in this browser :(");
    }
  };
}
  
if (window.matchMedia("(orientation: portrait)").matches) {
   // you're in PORTRAIT mode
}

if (window.matchMedia("(orientation: landscape)").matches) {
   // you're in LANDSCAPE mode
}