$red: #ff0000; html, body { width: 100%; } .border-right { &::after { position: absolute; content: " "; height: 100%; width: 1px; background-color: #fff; top: 50%; transform: translateY(-50%); } } .mg-auto { margin: 0 auto; } .clearfix { &::after { content: ""; height: 0; display: block; clear: both; } } // 字体或者什么的用em,距离用% @function em($v, $f:16) { @return $v/$f+em; } $designWidth:1920px; @function per($v) { @return $v/$designWidth+'%'; }