/* Required 22: perspective format carousel. Plain HTML remains a card grid. */
.format-carousel-controls { display: none; }
#format-carousel-help { display: none; }
.format-carousel-ready #format-carousel-help { display: block; }
.format-card-choice { background: linear-gradient(135deg, var(--surface-purple), var(--color-white) 70%); }
.format-card-choice .format-top svg { transform: rotate(-3deg); }
.format-carousel { min-width: 0; }
.format-carousel-ready {
  overflow: hidden;
  overflow: clip;
  margin: -12px -16px 0;
  padding: 0 16px 12px;
}
.format-carousel-ready .format-grid {
  position: relative;
  display: block;
  perspective: 1400px;
  min-height: 440px;
  touch-action: pan-y pinch-zoom;
  outline: none;
  --carousel-shift: clamp(165px, 31vw, 365px);
}
.format-carousel-ready .format-grid:focus-visible {
  outline: 2px solid var(--color-purple);
  outline-offset: -4px;
  border-radius: var(--radius-card);
}
.format-carousel-ready .format-grid > .format-card {
  position: absolute;
  left: 50%;
  top: 34px;
  width: min(52%, 570px);
  min-width: 0;
  margin: 0;
  transform-origin: center center;
  transform: translateX(-50%);
  opacity: 1;
  z-index: 2;
  transition: transform .65s cubic-bezier(.22,.7,.25,1), opacity .65s ease, box-shadow .35s;
  backface-visibility: hidden;
}
.format-carousel-ready .format-grid > .format-card[data-carousel-position='previous'] {
  transform: translateX(calc(-50% - var(--carousel-shift))) rotateY(27deg) scale(.8);
  opacity: .82;
  z-index: 1;
}
.format-carousel-ready .format-grid > .format-card[data-carousel-position='next'] {
  transform: translateX(calc(-50% + var(--carousel-shift))) rotateY(-27deg) scale(.8);
  opacity: .82;
  z-index: 1;
}
.format-carousel-ready .format-grid > .format-card[data-carousel-position='active'] {
  transform: translateX(-50%) rotateY(0deg) scale(1);
  box-shadow: var(--shadow-lift);
}
.format-carousel-ready .format-card > p { min-height: 5.4em; }
.format-carousel-ready .format-carousel-controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 23px;
  margin-top: 5px;
}
.carousel-arrow {
  display: grid;
  place-items: center;
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  padding: 0;
  border: 1px solid var(--color-line);
  border-radius: 50%;
  background: var(--color-white);
  color: var(--color-purple);
  box-shadow: var(--shadow-card);
  font: 23px var(--font);
  cursor: pointer;
  transition: background .25s, transform .25s;
}
.carousel-arrow:hover { background: var(--surface-lilac); transform: translateY(-2px); }
.carousel-arrow:focus-visible { outline: 2px solid var(--color-purple); outline-offset: 4px; }
.carousel-position { min-width: 145px; text-align: center; }
.carousel-position > span { display: block; }
.carousel-index { color: var(--color-purple); font-size: 14px; font-weight: 600; letter-spacing: .14em; }
.carousel-name { margin-top: 5px; color: var(--color-muted); font-size: 12px; }

/* Required 23: native, keyboard-accessible theme selection in the header. */
.theme-control {
  position: relative;
  display: inline-flex;
  align-items: center;
  flex: 0 0 44px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-line);
  border-radius: 24px;
  color: var(--color-purple);
  background: var(--surface-lilac);
}
.theme-control svg {
  position: absolute;
  left: 11px;
  top: 11px;
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  pointer-events: none;
}
.theme-control select {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 0;
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: inherit;
  appearance: none;
  -webkit-appearance: none;
  background: transparent;
  color: var(--color-ink);
  font: 0 var(--font);
  cursor: pointer;
}
.theme-control select option { font: 14px var(--font); color: var(--color-ink); background: var(--color-white); }
.theme-control select:focus-visible { outline: 2px solid var(--color-purple); outline-offset: 4px; }
@media (min-width: 1280px) {
  .theme-control { width: 112px; flex-basis: 112px; }
  .theme-control select { padding: 0 10px 0 37px; font-size: 12px; }
  .header-inner { gap: 22px; }
  .desktop-nav { gap: 22px; }
}
@media (max-width: 1279px) and (min-width: 981px) {
  .header-inner { gap: 15px; }
  .desktop-nav { gap: 15px; }
  .header-book { padding-inline: 14px; gap: 10px; }
}
@media (max-width: 980px) {
  .format-carousel-ready .format-grid { --carousel-shift: 29vw; }
  .format-carousel-ready .format-grid > .format-card { width: 62%; padding: 28px; }
}
@media (max-width: 640px) {
  .header-inner { gap: 10px; }
  .theme-control { margin-left: auto; flex-basis: 40px; width: 40px; height: 40px; }
  .theme-control svg { left: 9px; top: 9px; }
  .menu-toggle { margin-left: 0; }
  .format-carousel-ready { margin-inline: -20px; padding-inline: 20px; }
  .format-carousel-ready .format-grid { --carousel-shift: 79%; min-height: 420px; }
  .format-carousel-ready .format-grid > .format-card { width: calc(100% - 22px); padding: 25px; top: 28px; }
  .format-carousel-ready .format-grid > .format-card[data-carousel-position='previous'] {
    transform: translateX(calc(-50% - var(--carousel-shift))) rotateY(22deg) scale(.86);
  }
  .format-carousel-ready .format-grid > .format-card[data-carousel-position='next'] {
    transform: translateX(calc(-50% + var(--carousel-shift))) rotateY(-22deg) scale(.86);
  }
  .format-carousel-ready .format-card h3 { font-size: 26px; }
  .format-carousel-ready .format-top { gap: 9px; }
  .format-carousel-ready .format-top svg { width: 59px; height: 59px; flex-shrink: 0; }
  .format-carousel-ready .format-top > span { max-width: 115px; }
  .format-carousel-ready .format-bottom { gap: 12px; }
  .format-carousel-controls { gap: 15px; }
}
@media (max-width: 360px) {
  .header-inner { gap: 7px; }
  .header-inner .brand { font-size: 19px; gap: 7px; }
  .header-inner .brand svg { width: 31px; height: 31px; }
  .header-inner .menu-toggle { flex-shrink: 0; }
  .format-carousel-ready { margin-inline: -16px; padding-inline: 16px; }
  .format-carousel-ready .format-grid > .format-card { padding: 24px 21px; }
  .format-carousel-ready .format-card h3 { font-size: 24px; }
  .format-carousel-ready .format-card > p { font-size: 13px; }
}
html.reduce-motion .format-carousel-ready .format-grid > .format-card,
html.reduce-motion .carousel-arrow { transition: none; }
html.reduce-motion .format-carousel-ready .format-grid > .format-card[data-carousel-position='previous'] {
  transform: translateX(calc(-50% - var(--carousel-shift))) scale(.82);
}
html.reduce-motion .format-carousel-ready .format-grid > .format-card[data-carousel-position='next'] {
  transform: translateX(calc(-50% + var(--carousel-shift))) scale(.82);
}
@media (prefers-reduced-motion: reduce) {
  .format-carousel-ready .format-grid > .format-card { transition: none; }
  .format-carousel-ready .format-grid > .format-card[data-carousel-position='previous'] { transform: translateX(calc(-50% - var(--carousel-shift))) scale(.82); }
  .format-carousel-ready .format-grid > .format-card[data-carousel-position='next'] { transform: translateX(calc(-50% + var(--carousel-shift))) scale(.82); }
}