bro, can u please help me to do my site faster then before? have so many css files in theme.. can u tell that in in which files we need to change?
example..
1. i copied all css files with the name of main.css
2. now how i want to gave direction to html to check css in main.css?
3.in which which files we need to change style.css, responcive.css etc... to main.css

i hope u understand what i am trying to discuss.. and this is also most imp for so many new entry website owners to decrease loading time and increse page speed and gd for seo..

thank u

@Ghany
All styles for theme are included in head.php, plugin may pull it's style via hook.

oh ok ok thank u bro... i will try if i face any issue can u help me in that? and also i am using child theme for this changes

@Ghany
There is not much I can help as everything is in head.php.