html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;          /* smooth anchor scroll */
  overflow-y: scroll;               /* force body to be scrollable */
  scroll-snap-type: y mandatory;    /* enable vertical snap */
}

.stage {
  min-height: 100vh;                /* each fills screen */
  scroll-snap-align: start;         /* snap to top */
  scroll-snap-stop: always;         /* (optional) stricter snap */
}