/* D S1: one scroll owner on the measured home/menu document only.
 * Keep the current live safe-area values and responsive layout. In particular,
 * do not retain page geometry, move the footer, or correct scroll on resize.
 * The video shell and all independently authored lesson pages are excluded.
 */
html[data-d-single-scroll="s1"][data-d-video-only="true"]:not([data-d-viewport-shell="true"]) {
    height: 100%;
    overflow: hidden !important;
}

html[data-d-single-scroll="s1"][data-d-video-only="true"]:not([data-d-viewport-shell="true"]) body:not(.lesson-intro-body) {
    box-sizing: border-box;
    min-height: 0;
    height: 100%;
    overflow-x: hidden;
    /* No !important: existing modal inline overflow:hidden must still win. */
    overflow-y: auto;
}