:root {
  --shared-shell-min-height: 100vh;
}

@supports (height: 100dvh) {
  :root {
    --shared-shell-min-height: 100dvh;
  }
}

/*
  Sticky footer layout:
  - short pages: footer stays at viewport bottom
  - long pages: footer flows below content and appears after scrolling
*/
.site-shell {
  min-height: var(--shared-shell-min-height);
  display: flex;
  flex-direction: column;
}

.page-main {
  flex: 1 0 auto;
}

.site-footer {
  margin-top: auto;
}