Using Ionic Framework Web Components

I’ve built a website using the classical way, and then when ionic v4 introduced I thought adding some material design components and as Ionic is now shipped as web components as well I said why not add their components instead, so I did add the ionic script and style tags as illustrated in the Ionic framework docs, but when I ran the page my page scrolling was disabled, and then I found that it’s done cause of the scroll overflow style, so I did add this to my HTML index page to solve it

        <ion-content overflow-scroll="true">
<Rest OF my HtML goes here>

but the issue is some of my page containers styles are ruined due to ionic CSS

<link href="" rel="stylesheet">

So is there a way to load ionic in a way that it won’t conflict with already used and loaded CSS styles, or Should I convert my page to my ionic PWA setup to fix it?

Any tips would be appreciated…