Not responsive anmore

Hi all,

As I was trying to optimize my website for SEO purposes, I was surprised that my website is no longer responsive. I added a snippet on the .htaccess codes and did something on the website like some other things like css minifier, HTML Compression/GZIP Test but I really think there’s something wrong with my .htaccess so I revert it back to the same old codes but it’s still the same. Can anyone please help me out? Would really appreciate it.