如何观察普通JS ES6定制元素中计算出的css属性的变化

const observer = new MutationObserver(callback);

function callback(mutationsList, observer) {
  for (let mutation of mutationsList) {
    if (mutation.type === 'attributes') {
      console.log('属性变化:', mutation.attributeName);
      console.log('新值:', mutation.target.getAttribute(mutation.attributeName));
    }
  }
}

const targetElement = document.querySelector('#target');
observer.observe(targetElement, { attributes: true });

targetElement.style.color = 'red';

const observer = new MutationObserver(callback);

function callback(mutationsList, observer) {
  for (let mutation of mutationsList) {
    if (mutation.type === 'attributes') {
      console.log('属性变化:', mutation.attributeName);
      console.log('新值:', mutation.target.getAttribute(mutation.attributeName));
    }
  }
}

const targetElement = document.querySelector('#target');
observer.observe(targetElement, { attributes: true });

targetElement.style.color = 'red';