*{box-sizing:border-box}
body{margin:0;background:#f5f7fa;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Hiragino Sans,sans-serif;font-size:15px;line-height:1.6;color:#374151}
.main{margin-left:17rem;flex:1;padding:3rem 3.5rem}
.content{max-width:52rem}