For the output of post content, the main column is constrained to 700px. This allows for images etc. to be aligned left and right whilst remaining within the content column.

Adding a solution using a combination of left and translateX to “stretch” the width of elements marked with .alignwide or .alignfull outside the containing column works fine. However, when the element – e.g. a Cover Block – is marked with the class name has-parallax to allow a background image with background-attachment: fixed, the background image is also transformed relative to the browser window and hence cropped.

Does anyone understand why this is the case, or have a solution? A very simplified example of this occurrence is in this Pen: https://codepen.io/permanenttourist/pen/LYVZOpN?editors=1100