我试图创建一个页脚停留在底部，但它不起作用

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.content {
  flex-grow: 1;
}

.footer {
  align-self: flex-end;
}

.footer {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
}

window.addEventListener('DOMContentLoaded', () => {
  const content = document.querySelector('.content');
  const footer = document.querySelector('.footer');

  function adjustFooterPosition() {
    const contentHeight = content.offsetHeight;
    const viewportHeight = window.innerHeight;

    if (contentHeight < viewportHeight) {
      footer.style.position = 'fixed';
      footer.style.bottom = 0;
    } else {
      footer.style.position = 'static';
    }
  }

  adjustFooterPosition();
  window.addEventListener('resize', adjustFooterPosition);
});