thinigyThingy.js

document.querySelectorAll('.sviHoverKurci').forEach((elem) => {
  const fn = (add) => () => {
    const thingy = document.querySelector('.thingy');
    if (add) {
      thingy.classList.add('.class');
    } else {
      thingy.classList.remove('.class');
    }
  };

  elem.addEventListener('mouseeneter', fn(true));
  elem.addEventListener('mouseexit', fn(false));
});