js 给body 加css

document.body.style.backgroundColor = 'lightblue';
document.body.style.fontFamily = 'Arial, sans-serif';

const style = document.createElement('style');
style.innerHTML = `
  body {
    background-color: lightblue;
    font-family: Arial, sans-serif;
  }
`;
document.head.appendChild(style);

const link = document.createElement('link');
link.rel = 'stylesheet';
link.href = 'path/to/your/stylesheet.css';
document.head.appendChild(link);

body {
  background-color: lightblue;
  font-family: Arial, sans-serif;
}

.custom-body-style {
  background-color: lightblue;
  font-family: Arial, sans-serif;
}

document.body.classList.add('custom-body-style');