The website uses bootstrap 3.4.1 framework. Bootstrap 4.3.1 is available since quite a while. According to the migration docs:
Moving from Beta 3 to our stable v4.0 release, there are no breaking changes, but there are some notable changes.
which sounds like it's backward compatible. I did a quick test and it does indeed look like the JavaScript (bootstrap.min.js) framework is backward compatible, but dropping in the CSS file (bootstrap.min.css) breaks the layout, the navigation pane, icons, etc.
The website uses bootstrap 3.4.1 framework. Bootstrap 4.3.1 is available since quite a while. According to the migration docs:
which sounds like it's backward compatible. I did a quick test and it does indeed look like the JavaScript (
bootstrap.min.js) framework is backward compatible, but dropping in the CSS file (bootstrap.min.css) breaks the layout, the navigation pane, icons, etc.