bfgeek/css-ui-nav.js

## css-ui-nav.js
window.addEventListener("keydown", (evt) => {
  let prop = '--nav-';
  switch (evt.key) {
    case "ArrowDown":
      prop += 'down';
      break;
    case "ArrowUp":
      prop += 'up';
      break;
    case "ArrowLeft":
      prop += 'left';
      break;
    case "ArrowRight":
      prop += 'right';
      break;
    default:
      return;
  }

  const id = getComputedStyleMap(evt.target).get(prop).cssText;

  const focusEl = document.getElementById(id);
  focusEl.focus();

  evt.preventDefault();
}, true);