An alternative to normalize.css, but more handy and practical.
`font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, // 英文
"PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; // 中文`
div、ul、li、p、hn
h1……h6