You can limit specific code and css to a specific page or post using templates or with a plugin as already recommended above.
]]>I also agree with Codeforest, wp_enqueue_script and wp_enqueue_style are the way to go, especially if you are using a minify plugin, they usually only minify code and script loaded via the enqueue function
]]>With built in WordPress function you can easily control script dependencies and make sure that nothing is included twice …
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