:root {
  --font-sans: 'PingFang SC', 'PingFang TC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Microsoft JhengHei', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', -apple-system, BlinkMacSystemFont, Roboto, Arial, sans-serif;
  --font-serif: 'Songti SC', 'Songti TC', 'STSong', 'PMingLiU', 'MingLiU', 'Hiragino Mincho ProN', 'Yu Mincho', Georgia, serif;
  --default-font-family: var(--font-sans);
}