/* Shared return controls: aligned with content, sized to their label. */
.cupec-rebuild main > [data-page] > .page-backbar {
  width: 100%;
  max-width: none;
  margin: 0;
  padding: 24px var(--rb-gutter);
}
.cupec-rebuild .page-return {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex: 0 0 auto;
  width: fit-content;
  max-width: 100%;
  min-height: 44px;
  margin: 0;
  padding: 9px 14px;
  border: 1px solid var(--rb-line);
  background: var(--rb-paper);
  color: var(--rb-ink);
  font: 400 12px/1.4 var(--rb-sans);
  letter-spacing: 0;
  text-decoration: none;
  text-align: left;
}
.cupec-rebuild .page-return:hover { background: var(--rb-soft); }
.cupec-rebuild .page-return > span { font-size: 19px; line-height: 1; flex-shrink: 0; }
.cupec-rebuild .event-header > .page-return:last-child { font-size: 12px; }
@media(max-width:767px) {
  .cupec-rebuild main > [data-page] > .page-backbar { padding-block: 18px; }
  .cupec-rebuild .page-return { min-height: 48px; }
  .cupec-rebuild .reader-bar { gap: 12px; align-items: center; }
  .cupec-rebuild .reader-bar #pdf-download { display: inline-flex; align-items: center; min-height: 48px; }
}
/* The editorial title band stays full-width at the mobile breakpoint. */
.cupec-rebuild main > [data-page].info-page > .info-heading {
  width: 100%;
  max-width: none;
  margin-inline: 0;
}
.cupec-rebuild .info-body > h2:first-child { margin-top: 0; }
@media(max-width:767px) {
  .cupec-rebuild main > [data-page].info-page > .info-heading { padding: 48px var(--rb-gutter); }
}
@media(max-width:767px) {
  .cupec-rebuild .reader-bar { display: grid; grid-template-columns: minmax(0, 1fr) auto; }
  .cupec-rebuild .reader-bar label { display: flex; align-items: center; gap: 8px; }
  .cupec-rebuild .reader-bar #pdf-download { grid-column: 1 / -1; justify-self: start; margin-left: 0; }
}

/* A compact header and a true overlay menu share one navigation layout. */
html.cupec-menu-open, html.cupec-menu-open body { overflow: hidden; overscroll-behavior: none; }
@media (min-width: 768px) {
  body.cupec-rebuild .rb-header.navigation-shell {
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: space-between;
    min-height: 88px;
    padding-block: 16px;
  }
  body.cupec-rebuild .navigation-shell .menu-toggle { display: none; }
  body.cupec-rebuild .rb-header.navigation-shell nav {
    position: static;
    display: flex;
    flex-direction: row;
    width: auto;
    height: auto;
    max-height: none;
    gap: 28px;
    padding: 0;
    border: 0;
    visibility: visible;
    opacity: 1;
    clip-path: none;
    transform: none;
    pointer-events: auto;
  }
  body.cupec-rebuild .rb-header.navigation-shell nav > a {
    font: 450 13px/1.4 var(--rb-sans);
    padding: 10px 0;
    color: var(--rb-ink);
  }
  body.cupec-rebuild .rb-header.navigation-shell nav > .join-link {
    min-height: 42px;
    padding: 11px 18px;
    border: 1px solid var(--rb-line);
  }
}
@media (max-width: 767px) {
  body.cupec-rebuild :is(.rb-header,.event-header,.challenge-sidebar).navigation-shell {
    position: sticky;
    top: 0;
    z-index: 80;
    height: calc(76px + env(safe-area-inset-top));
    min-height: calc(76px + env(safe-area-inset-top));
    padding: calc(10px + env(safe-area-inset-top)) 24px 10px;
    flex-wrap: nowrap;
    background: var(--rb-paper);
    border-bottom: 1px solid var(--rb-line);
  }
  body.cupec-rebuild .navigation-shell .rb-brand > img { width: 42px; height: 42px; }
  body.cupec-rebuild .navigation-shell .rb-brand > span { font-size: 25px; }
  body.cupec-rebuild :is(.rb-header,.event-header,.challenge-sidebar).navigation-shell nav {
    position: fixed;
    inset: calc(76px + env(safe-area-inset-top)) 0 0;
    height: calc(100dvh - 76px - env(safe-area-inset-top));
    max-height: none;
    width: 100%;
    padding: 28px 24px calc(32px + env(safe-area-inset-bottom));
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    gap: 0;
    overflow-y: auto;
    border: 0;
    background: var(--rb-paper);
    visibility: hidden;
    pointer-events: none;
    opacity: 0;
    clip-path: none;
    transform: translateY(-8px);
    transition: opacity .18s ease, transform .18s ease, visibility 0s .18s;
  }
  body.cupec-rebuild :is(.rb-header,.event-header,.challenge-sidebar).navigation-shell.menu-open nav {
    visibility: visible;
    pointer-events: auto;
    opacity: 1;
    transform: none;
    transition-delay: 0s;
  }
  body.cupec-rebuild :is(.rb-header,.event-header,.challenge-sidebar).navigation-shell nav > a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex: 0 0 auto;
    width: 100%;
    min-height: 76px;
    margin: 0;
    padding: 16px 0;
    border: 0;
    border-bottom: 1px solid var(--rb-line);
    background: transparent!important;
    font: 400 36px/1.2 var(--rb-serif);
    letter-spacing: -.02em;
    color: var(--rb-ink)!important;
    text-decoration: none;
  }
  body.cupec-rebuild .navigation-shell nav > a[aria-current=page] { font-weight: 400; color: #737d68!important; }
  body.cupec-rebuild .navigation-shell nav > a::before,
  body.cupec-rebuild .navigation-shell nav > a::after { display: none!important; }
}
@media (prefers-reduced-motion: reduce) {
  body.cupec-rebuild .navigation-shell nav { transition: none!important; }
}