比较两个字符串，忽略空格，换行和换行符

我想比较两个字符串并突出显示匹配连续的4个或更多单词。

当字符串中有双倍空格或换行时，出现问题，字符串未突出显示。

Lorem ipsum, or lipsum as it is sometimes known, is dummy text used in laying out print, 
graphic or web designs.

laying out print, graphic

预期产量：

Lorem ipsum, or lipsum as it is sometimes known, is dummy text used in <span style="color:red">laying out print, 

graphic</span> or web designs.

PHP代码：

<?php
$str1 ="Lorem ipsum, or lipsum as it is sometimes known, is dummy text used in laying out print, 
graphic or web designs.";

$str2 = "/laying out print, graphic/iu";

echo preg_replace($str2, '<span style="color:red">$0</span>', $str1);
?>

注意：String1格式应相同。

$answer