True .alignfull

index.css

main .alignfull {
  margin: 2rem calc(50% - (50vw - var(--scrollbar-width) / 2)) !important;
  max-width: calc(100vw - var(--scrollbar-width)) !important;
  width: calc(100vw - var(--scrollbar-width));
}

index.js

function _calculateScrollbarWidth() {
    document.documentElement.style.setProperty('--scrollbar-width', (window.innerWidth - document.documentElement.clientWidth) + "px");
}
window.addEventListener('resize', _calculateScrollbarWidth, false);
document.addEventListener('DOMContentLoaded', _calculateScrollbarWidth, false);
window.addEventListener('load', _calculateScrollbarWidth);