Framework7 572,986 arranges an app in four levels. The app root (<div id="app">) gains the framework7-root class at startup. Inside it sit views: a view (.view) is a separate navigation stack with its own router and history. Each view holds pages (.page), and a page holds its navbar, toolbar and one .page-content, the only element that scrolls, which is why the bars stay put without position: fixed.
The router moves pages through three classes: page-next while a page slides in, page-current on screen, and page-previous for the page behind it, kept in the DOM so swipe-back can reveal it instantly. Views can live in a panel, a popup or a tab; view-main marks the one that receives links clicked outside any view. Give each independent history its own view: three tabs mean three views, but a detail page is just another page.