react app, assets path change

Hello, Im helping a friend to solve an issue a previous developer left, but Im new on React, so I don't know how to solve this issue:

He was integrating a html template he bought with React for his store site (he sells courses). The problem is when we click and open a detail of tutor or a detail of a course, the inner Source structure change, making the app lost the path to the '/assets' folder, making that all the pages to lost the styling.

for most of the pages this is the structure, and works fine, for example the checkout page:

but when I enter on a detail, the structure changes:

As you can see, on the detail, a 'tutorDetail' folder is created and inside is the 'localhost:3000/tutorDetail/assets' folder with the css and js, while the original 'localhost:3000/asset' folder is now empty, after that when I go to any other page, all are a white mess of words and images.

The site was builded on a component called 'Home' and is build like this:

return (

        <Fragment>

            <Header />

                <div className="sg-page-content">

                    <div className="sg-section">

                        <div className="section-content sg-filter-content list-view-tab section-padding">

                            <div className="container">

                                <Content />

                            </div>

                        </div>

                    </div>

                </div>

            <Footer />

        </Fragment>

    )

and in the 'Content' component is where all the pages are render:

return (

        <Router>

            <Switch>

                <Route path="/courses" component={Courses}/>

                <Route path="/school" component={Schools}/>

                <Route path="/tutordetail/:tutor" component={TutorDetail}/>

                <Route path="/blog" component={Blog}/>

                <Route path="/coursedetails/:course" component={CourseDetail} />

                <Route path="/schooldetails/:school" component={SchoolDetail} />

                <Route path="/blogdetail/:idPost" component={BlogDetail}/>

                <Route path="/login" component={Login}/>

                <Route path="/register" component={Registro}/>

                <Route path="/cart" component={Cart}/>

                <Route path="/checkout" component={Checkout}/>

                <Route path="/" component={Index}/>

            </Switch>

        </Router>

    )