Centaurette

I deleted all those too when I was attempting to troubleshoot- didn’t work. The code is displayed, but doesn’t work as intended.

I tried including the 'tab.html' and ‘content.html’ into my 'index.html' (using w3school code: how to include HTML, found at: https://www.w3schools.com/howto/howto_html_include.asp), but the javascript and css elements do not work. The buttons don't work as intended. Look at:
https://rads-198409.appspot.com

If you minimize the browser window, the tab is supposed to change to a drop-down menu, but the button does not work at all. I have checked the individual pages and they seem to work just fine, just not when they are combined. 

Am I doing something wrong? Could someone help? All the code I used is from w3school and I have only modified the file names (tab.html and content .html to point to the right files). Below are links to the code:

Code for ‘tab.html’ - https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_topnav

Code for ‘content.html’ - https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_collapsible_symbol

Code for ‘index.html’ - https://www.w3schools.com/howto/tryit.asp?filename=tryhow_html_include_2