This part is inside a .container class.
The .container class provides a responsive fixed width container.
Resize the browser window to see that its width (max-width) will change at different breakpoints.
This part is inside a .container-fluid class.
The .container-fluid class provides a full width container, spanning the entire width of the viewport.
This container has a top padding of 16 pixels (.pt-3).
Try to remove the .pt-3 class to see the difference.
This container has a border and some extra padding and margins.
This container has a dark background color and a white text, and some extra padding and margins.
This container has a blue background color and a white text, and some extra padding and margins.
Resize the browser window to see the effect.