Instructor: Let's start out by targeting the main element. We'll set its margin left property to five rem. This five rem equals the width of the nav element. For the width, let's take width and we'll set that to a calc function of 100 percent minus 25 rem. Here, the 25 rem comes from the 5 rem width of the nav element plus the 20 rem width of the aside element.
When I resize my window, the main element is still positioned in the correct location, and it grows and shrinks depending on the remaining available space. We can take this one step further by repeating this pattern inside of a MIDI query to ensure that the layout functions properly even when the elements change size.
If I resize my window, the nav and aside elements shrink, and the main element continues to take up the remaining space, thanks to the calc function.