Could I only add my css and jquery code to the entire site?

Hey I looked at the videos you made on Youtube, and tried lots of times, it seems that the HTML codes inside the “Page” section do not work, I must to create an HTML code section in the “CSS & Javascript Toolbox” dashboard which parallel to the CSS code and JS code I made, to make them work, is that true?

Currently I only put CSS and JS code inside the “CSS & Javascript Toolbox” dashboard, and assign the pages, but all these pages give me blank.

Could you please let me know if I made any mistakes? Because if I need to put every HTML code inside the “CSS & Javascript Toolbox” dashboard, it will waste too much time and very inconvenience.

Thank you

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