html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.single-container {
  width: 100%;
  flex: 1;  /* 填充剩余空间，推底 footer */
  padding-top: 120px;
  padding-left: 20px;
  padding-right: 20px;
  max-width: 800px;
  margin: 0 auto; 
  font-family: 'Noto Serif SC', serif;
}

.footer-nav {
  padding: 20px;
  text-align: center;
  color: var(--text-color);
  font-size: 14px;
}

.footer-single {
  padding: 20px;
  text-align: center;
  margin-top: 60px;
  padding-bottom: 40px;
}

.footer-inner {
  max-width: 760px;
  margin: 0 auto;
}