/* SETS Book Showcase — 3D Smart Series books and the page-turning reader (includes/book-showcase.php) */

/* ---------- 3D book ---------- */
.sb3d { --w: clamp(190px, 24vw, 290px); --h: calc(var(--w) * 1.25); --t: calc(var(--w) * .09);
  --pose: 26deg; --turn: 0deg; --tilt-x: 0deg; --tilt-y: 0deg;
  position: relative; width: var(--w); height: var(--h); margin-inline: auto; perspective: 1700px; }
.sb3d-sm { --w: 112px; --t: 11px; }
.sb3d-float { position: absolute; inset: 0; transform-style: preserve-3d; animation: sb-float 7s ease-in-out infinite; }
.sb3d-book { position: absolute; inset: 0; transform-style: preserve-3d;
  transform: rotateX(calc(5deg + var(--tilt-x))) rotateY(calc(var(--turn) + var(--pose) + var(--tilt-y)));
  transition: transform 1s cubic-bezier(.2, .8, .2, 1); }
.sb3d.is-tilting .sb3d-book { transition: transform .35s cubic-bezier(.2, .8, .2, 1); }
.sb-row:hover .sb3d, .sb-mini:hover .sb3d, .sb3d:focus-within { --pose: -20deg; }
.sb3d.is-turned { --turn: 180deg; }

.sb3d-face { position: absolute; inset: 0; overflow: hidden; backface-visibility: hidden; background: #fff; }
.sb3d-face img { display: block; width: 100%; height: 100%; object-fit: cover; }
.sb3d-front { transform: translateZ(calc(var(--t) / 2)); border-radius: 2px 7px 7px 2px;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .25); }
.sb3d-back { transform: rotateY(180deg) translateZ(calc(var(--t) / 2)); border-radius: 7px 2px 2px 7px; }
/* hinge crease and light falloff, like a printed paperback */
.sb3d-front::after, .sb3d-back::after { content: ""; position: absolute; inset: 0; pointer-events: none;
  background: linear-gradient(90deg, rgba(0, 0, 0, .32) 0, rgba(255, 255, 255, .22) 1.6%, rgba(0, 0, 0, .1) 3.4%, transparent 7%, transparent 80%, rgba(0, 0, 0, .08)); }
.sb3d-back::after { transform: scaleX(-1); }
.sb3d-gloss { position: absolute; inset: 0; z-index: 1; pointer-events: none; transform: translateX(-130%);
  background: linear-gradient(115deg, transparent 35%, rgba(255, 255, 255, .5) 50%, transparent 65%); }
.sb-row:hover .sb3d-gloss, .sb-mini:hover .sb3d-gloss { animation: sb-gloss 1.3s cubic-bezier(.3, .7, .3, 1) .15s; }

.sb3d-spine { position: absolute; top: 0; left: calc(50% - var(--t) / 2); width: var(--t); height: 100%;
  transform: rotateY(-90deg) translateZ(calc(var(--w) / 2)); display: grid; place-items: center; overflow: hidden;
  background: linear-gradient(90deg, rgba(0, 0, 0, .35), transparent 30%, rgba(255, 255, 255, .18) 55%, rgba(0, 0, 0, .3)), var(--spine); }
.sb3d-spine span { writing-mode: vertical-rl; color: #fff; font-weight: 800; letter-spacing: .14em; text-transform: uppercase;
  font-size: calc(var(--t) * .42); white-space: nowrap; text-shadow: 0 1px 2px rgba(0, 0, 0, .4); }
.sb3d-edge { position: absolute; background: #f3efe6; }
.sb3d-edge-fore { top: 3px; left: calc(50% - var(--t) / 2); width: var(--t); height: calc(100% - 6px);
  transform: rotateY(90deg) translateZ(calc(var(--w) / 2 - 3px));
  background: repeating-linear-gradient(90deg, #f7f4ee 0 1px, #ddd6c8 1px 2px), #f3efe6;
  box-shadow: inset 0 0 6px rgba(0, 0, 0, .2); }
.sb3d-edge-top, .sb3d-edge-bottom { left: 0; top: calc(50% - var(--t) / 2); width: calc(100% - 3px); height: var(--t);
  background: repeating-linear-gradient(0deg, #f7f4ee 0 1px, #ddd6c8 1px 2px); }
.sb3d-edge-top { transform: rotateX(90deg) translateZ(calc(var(--h) / 2 - 3px)); }
.sb3d-edge-bottom { transform: rotateX(-90deg) translateZ(calc(var(--h) / 2 - 3px)); }

.sb3d-shadow { position: absolute; left: 6%; right: 6%; bottom: calc(var(--h) * -.13); height: calc(var(--h) * .1);
  background: radial-gradient(ellipse at center, rgba(15, 23, 42, .42), transparent 70%); filter: blur(5px);
  animation: sb-shadow 7s ease-in-out infinite; }
.sb3d-aura { position: absolute; inset: -22%; border-radius: 50%; opacity: .38; filter: blur(46px); pointer-events: none;
  background: conic-gradient(from 0deg, var(--glow), transparent 28%, var(--spine), transparent 68%, var(--glow));
  animation: sb-spin 20s linear infinite; }
.sb3d-sm .sb3d-aura { inset: -12%; filter: blur(26px); opacity: .3; }
[data-theme="dark"] .sb3d-aura { opacity: .5; }

/* preview pages that fan out from behind the book */
.sb3d-fan img { position: absolute; top: 5%; left: 8%; width: 84%; height: 90%; object-fit: cover; border-radius: 4px;
  box-shadow: 0 18px 40px rgba(15, 23, 42, .28); opacity: 0; transform: none;
  transition: transform .8s cubic-bezier(.2, .8, .2, 1), opacity .5s; }
.sb3d-sm .sb3d-fan { display: none; }
@media (hover: hover) {
  .sb-row:hover .sb3d-fan img { opacity: 1; }
  .sb-row:hover .sb3d-fan img:nth-child(1) { transform: translateX(46%) translateY(-3%) rotate(9deg); transition-delay: .05s; }
  .sb-row:hover .sb3d-fan img:nth-child(2) { transform: translateX(-44%) translateY(-1%) rotate(-8deg); transition-delay: .12s; }
  .sb-row:hover .sb3d-fan img:nth-child(3) { transform: translateX(70%) translateY(6%) rotate(16deg); transition-delay: .19s; }
}

/* ---------- Full showcase rows ---------- */
.sb-showcase { display: grid; gap: 2rem; }
.sb-row { position: relative; isolation: isolate; overflow: hidden; display: grid; align-items: center;
  grid-template-columns: minmax(300px, .92fr) minmax(0, 1.08fr); gap: clamp(2rem, 5vw, 4.5rem);
  padding: clamp(1.5rem, 4vw, 3.25rem); border-radius: 28px; border: 1px solid var(--border);
  background: radial-gradient(circle at 18% 30%, color-mix(in srgb, var(--glow) 14%, transparent), transparent 55%),
              linear-gradient(150deg, color-mix(in srgb, var(--spine) 7%, var(--card)), var(--card));
  box-shadow: 0 30px 70px -40px rgba(15, 23, 42, .45); }
.sb-row::before { content: ""; position: absolute; inset: 0; z-index: -1; opacity: .5; pointer-events: none;
  background-image: radial-gradient(color-mix(in srgb, var(--spine) 22%, transparent) 1px, transparent 1px);
  background-size: 22px 22px; mask-image: linear-gradient(90deg, #000, transparent 45%); }
.sb-row-flip .sb-stage { order: 2; }
.sb-row-flip::before { mask-image: linear-gradient(270deg, #000, transparent 45%); }

.sb-stage { display: flex; flex-direction: column; align-items: center; gap: 4rem; padding-top: 1.5rem; }
.sb-stage-controls { display: flex; flex-wrap: wrap; justify-content: center; gap: .6rem; position: relative; z-index: 2; }
.sb-chip { display: inline-flex; align-items: center; gap: .45rem; border: 1px solid var(--border); border-radius: 999px;
  padding: .5rem 1rem; font-size: .85rem; font-weight: 600; color: var(--text); background: var(--glass);
  backdrop-filter: blur(10px); transition: transform .25s, border-color .25s, box-shadow .25s; }
.sb-chip:hover { transform: translateY(-2px); border-color: var(--glow); box-shadow: 0 10px 24px -12px var(--glow); }
.sb-chip i { color: var(--glow); }

.sb-kicker, .sb-eyebrow { display: inline-flex; align-items: center; gap: .4rem; font-size: .75rem; font-weight: 800;
  letter-spacing: .12em; text-transform: uppercase; color: var(--glow); }
.sb-title { margin: .5rem 0 .35rem; font-weight: 900; letter-spacing: -.02em; line-height: 1.05; font-size: clamp(2rem, 4vw, 3rem);
  background: linear-gradient(100deg, var(--text) 30%, var(--glow) 50%, var(--text) 70%); background-size: 250% 100%;
  -webkit-background-clip: text; background-clip: text; color: transparent; animation: sb-sheen 7s ease-in-out infinite; }
.sb-subtitle { font-size: 1.1rem; font-weight: 600; color: var(--text); opacity: .85; margin-bottom: .75rem; }
.sb-author { color: var(--muted); font-size: .92rem; margin-bottom: 1rem; }
.sb-author i { color: var(--glow); margin-right: .25rem; }
.sb-tagline { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1.1rem; }
.sb-tagline span { padding: .3rem .85rem; border-radius: 999px; font-size: .8rem; font-weight: 700; color: #fff;
  background: linear-gradient(135deg, var(--spine), color-mix(in srgb, var(--spine) 55%, var(--glow)));
  box-shadow: 0 8px 18px -10px var(--spine); animation: sb-pop .6s cubic-bezier(.3, 1.6, .5, 1) both;
  animation-delay: calc(var(--i) * .1s); }
.sb-desc { color: var(--muted); line-height: 1.7; margin-bottom: 1.1rem; }

.sb-contents { border: 1px solid var(--border); border-radius: 16px; background: var(--card); margin-bottom: 1.25rem; overflow: hidden; }
.sb-contents summary { list-style: none; cursor: pointer; display: flex; align-items: center; gap: .55rem; padding: .8rem 1rem; font-weight: 700; }
.sb-contents summary::-webkit-details-marker { display: none; }
.sb-contents summary > i:first-child { color: var(--glow); }
.sb-contents-caret { margin-left: auto; transition: transform .35s; font-size: .8rem; color: var(--muted); }
.sb-contents[open] .sb-contents-caret { transform: rotate(180deg); }
.sb-contents ol { margin: 0; padding: 0 1rem .9rem 2.4rem; columns: 2 220px; column-gap: 2rem; }
.sb-contents li { padding: .22rem 0; font-size: .9rem; break-inside: avoid; }
.sb-contents li::marker { color: var(--glow); font-weight: 800; }
.sb-contents[open] li { animation: sb-rise-in .45s both; animation-delay: calc(var(--i) * 35ms); }
.sb-contents-level { margin: .2rem 1rem .35rem; font-size: .75rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }

.sb-strip-label { font-size: .82rem; font-weight: 600; color: var(--muted); margin-bottom: .5rem; }
.sb-strip { display: flex; gap: .7rem; overflow-x: auto; padding: .4rem .2rem 1rem; margin-bottom: .5rem; scroll-snap-type: x proximity; scrollbar-width: thin; }
.sb-strip-page { position: relative; flex: 0 0 auto; width: 76px; aspect-ratio: .772; padding: 0; border: 0; border-radius: 6px;
  overflow: hidden; background: #fff; scroll-snap-align: start; box-shadow: 0 6px 16px -8px rgba(15, 23, 42, .45);
  transform-origin: bottom center; transition: transform .35s cubic-bezier(.2, .8, .2, 1), box-shadow .35s;
  animation: sb-rise-in .5s both; animation-delay: calc(var(--i) * 60ms); }
.sb-strip-page img { width: 100%; height: 100%; object-fit: cover; display: block; }
.sb-strip-page span { position: absolute; inset: auto 0 0; padding: .9rem .3rem .3rem; font-size: .58rem; font-weight: 700; line-height: 1.2;
  color: #fff; text-align: left; background: linear-gradient(transparent, rgba(10, 16, 36, .88)); opacity: 0; transform: translateY(6px); transition: .3s; }
.sb-strip-page:hover, .sb-strip-page:focus-visible { transform: translateY(-6px) rotate(-2deg) scale(1.06); box-shadow: 0 16px 28px -12px var(--glow); }
.sb-strip-page:hover span, .sb-strip-page:focus-visible span { opacity: 1; transform: none; }

.book-pages-showcase .sb-strip { flex-wrap: wrap; overflow: visible; gap: 1rem; }
.book-pages-showcase .sb-strip-page { width: calc(25% - .75rem); min-width: 110px; }
.book-pages-showcase .sb-strip-page span { font-size: .72rem; opacity: 1; transform: none; }

.sb-actions { display: flex; flex-wrap: wrap; align-items: center; gap: .65rem; }
.sb-badge { display: inline-flex; align-items: center; gap: .35rem; font-size: .8rem; font-weight: 700; color: #15803d;
  background: rgba(34, 197, 94, .12); padding: .4rem .8rem; border-radius: 999px; }
[data-theme="dark"] .sb-badge { color: #4ade80; }

@supports (animation-timeline: view()) {
  .sb-row { animation: sb-row-in linear both; animation-timeline: view(); animation-range: entry 0% cover 28%; }
}

/* ---------- Compact band (course catalogue, student dashboard) ---------- */
.sb-band { position: relative; border-radius: 24px; padding: clamp(1.25rem, 3vw, 2rem); border: 1px solid var(--border); overflow: hidden; isolation: isolate;
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 9%, var(--card)), var(--card) 60%, color-mix(in srgb, var(--secondary) 9%, var(--card))); }
.sb-band-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 1rem; margin-bottom: 1.25rem; }
.sb-band-head h2 { font-size: clamp(1.25rem, 2.4vw, 1.6rem); font-weight: 800; margin: .3rem 0 0; }
.sb-band .sb-eyebrow { color: var(--secondary); }
.sb-link { font-weight: 700; font-size: .9rem; white-space: nowrap; text-decoration: none; }
.sb-link i { transition: transform .25s; }
.sb-link:hover i { transform: translateX(4px); }
.sb-band-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.sb-mini { display: grid; grid-template-columns: 150px minmax(0, 1fr); align-items: center; gap: 1.1rem; padding: 1.1rem 1.25rem 1.1rem .5rem;
  border-radius: 20px; background: var(--glass); border: 1px solid var(--border); backdrop-filter: blur(10px);
  transition: transform .4s cubic-bezier(.2, .8, .2, 1), box-shadow .4s, border-color .4s;
  animation: sb-rise-in .7s cubic-bezier(.2, .8, .2, 1) both; animation-delay: var(--d); }
.sb-mini:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--glow) 45%, var(--border)); box-shadow: 0 24px 40px -26px var(--glow); }
.sb-mini-stage { display: grid; place-items: center; padding: .75rem 0 1.4rem; cursor: pointer; }
.sb-mini .sb-kicker { font-size: .66rem; }
.sb-mini h3 { font-size: 1.15rem; font-weight: 800; margin: .3rem 0 .25rem; }
.sb-mini p { font-size: .85rem; color: var(--muted); margin-bottom: .8rem; }
.sb-mini .sb-actions { gap: .45rem; }

@media (max-width: 991.98px) {
  .sb-row, .sb-row-flip { grid-template-columns: 1fr; text-align: left; }
  .sb-row-flip .sb-stage { order: 0; }
  .sb-row::before, .sb-row-flip::before { mask-image: linear-gradient(180deg, #000, transparent 45%); }
  .sb-band-grid { grid-template-columns: 1fr; }
}
@media (max-width: 575.98px) {
  .sb3d { --w: min(56vw, 230px); }
  .sb-mini { grid-template-columns: 112px minmax(0, 1fr); padding-left: .25rem; }
  .sb3d-sm { --w: 88px; --t: 9px; }
  .sb-band-head { align-items: flex-start; flex-direction: column; }
}

/* ---------- Page-turning reader ---------- */
html.sbr-lock { overflow: hidden; }
dialog.sbr { width: 100vw; height: 100dvh; max-width: none; max-height: none; margin: 0; padding: 0; border: 0; color: #fff;
  background: radial-gradient(circle at 50% 45%, color-mix(in srgb, var(--glow) 22%, #101a3a), #050915 72%); }
dialog.sbr[open] { display: flex; flex-direction: column; animation: sbr-in .45s cubic-bezier(.2, .8, .2, 1); }
dialog.sbr::backdrop { background: rgba(3, 7, 18, .7); backdrop-filter: blur(6px); }
.sbr-top, .sbr-foot { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: .9rem clamp(1rem, 3vw, 2rem); }
.sbr-top strong { display: block; font-size: 1.15rem; }
.sbr-kicker { font-size: .72rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; color: var(--glow); }
.sbr-close, .sbr-nav { display: grid; place-items: center; width: 46px; height: 46px; border-radius: 50%; color: #fff; flex: 0 0 auto;
  background: rgba(255, 255, 255, .1); border: 1px solid rgba(255, 255, 255, .18); transition: background .25s, transform .25s, opacity .25s; }
.sbr-close:hover, .sbr-nav:hover:not(:disabled) { background: rgba(255, 255, 255, .22); transform: scale(1.08); }
.sbr-nav:disabled { opacity: .25; cursor: default; }
.sbr-stage { flex: 1; min-height: 0; display: flex; align-items: center; justify-content: center; gap: clamp(.5rem, 2vw, 2rem); padding: 0 1rem; }
.sbr-book { --pw: min(40vw, calc((100dvh - 190px) * .772)); position: relative; width: calc(var(--pw) * 2); height: calc(var(--pw) / .772);
  perspective: 2600px; transition: transform .9s cubic-bezier(.645, .045, .355, 1); }
.sbr-book.at-start { transform: translateX(-25%); }
.sbr-book.at-end { transform: translateX(25%); }
.sbr-book::after { content: ""; position: absolute; left: 4%; right: 4%; bottom: -26px; height: 30px; z-index: -1;
  background: radial-gradient(ellipse, rgba(0, 0, 0, .55), transparent 70%); filter: blur(6px); }
.sbr-book.no-anim, .sbr-book.no-anim .sbr-leaf { transition: none !important; }
.sbr-leaf { position: absolute; top: 0; left: 50%; width: 50%; height: 100%; transform-origin: left center; transform-style: preserve-3d;
  cursor: pointer; transition: transform 1.05s cubic-bezier(.645, .045, .355, 1); }
.sbr-leaf.is-flipped { transform: rotateY(-180deg); }
.sbr-face { position: absolute; inset: 0; margin: 0; overflow: hidden; background: #fff; backface-visibility: hidden; border-radius: 0 6px 6px 0; }
.sbr-face img { display: block; width: 100%; height: 100%; object-fit: cover; }
.sbr-face-back { transform: rotateY(180deg); border-radius: 6px 0 0 6px; }
.sbr-face::after { content: ""; position: absolute; inset: 0; pointer-events: none;
  background: linear-gradient(90deg, rgba(0, 0, 0, .25), rgba(0, 0, 0, .05) 6%, transparent 14%, transparent 92%, rgba(0, 0, 0, .06)); }
.sbr-face-back::after { transform: scaleX(-1); }
.sbr-leaf.is-turning .sbr-face::before { content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background: linear-gradient(90deg, rgba(0, 0, 0, .35), transparent 70%); animation: sbr-shade 1.05s ease-in-out both; }
.sbr-blank { background: linear-gradient(135deg, #f8f6f0, #ebe6da); }
.sbr-foot { font-size: .85rem; }
.sbr-status { font-weight: 700; min-width: 0; }
.sbr-hint { color: rgba(255, 255, 255, .6); }

@media (max-width: 720px) {
  .sbr-stage { position: relative; padding: 0; }
  .sbr-book { display: flex; gap: 14px; width: 100%; height: auto; padding: 0 8vw; overflow-x: auto; scroll-snap-type: x mandatory;
    perspective: none; transform: none !important; scrollbar-width: none; }
  .sbr-book::-webkit-scrollbar { display: none; }
  .sbr-book::after { display: none; }
  .sbr-leaf { display: contents; }
  .sbr-face, .sbr-face-back { position: relative; flex: 0 0 84vw; max-height: calc(100dvh - 190px); aspect-ratio: .772; transform: none;
    backface-visibility: visible; border-radius: 8px; scroll-snap-align: center; box-shadow: 0 20px 40px -20px #000; }
  .sbr-face::after { display: none; }
  .sbr-blank { display: none; }
  .sbr-nav { position: absolute; z-index: 2; top: 50%; translate: 0 -50%; width: 40px; height: 40px; background: rgba(5, 9, 21, .55); }
  .sbr-prev { left: .4rem; }
  .sbr-next { right: .4rem; }
  .sbr-hint { display: none; }
}

/* ---------- Motion ---------- */
@keyframes sb-float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-12px); } }
@keyframes sb-shadow { 0%, 100% { transform: scale(1); opacity: 1; } 50% { transform: scale(.86); opacity: .7; } }
@keyframes sb-spin { to { transform: rotate(360deg); } }
@keyframes sb-gloss { to { transform: translateX(130%); } }
@keyframes sb-sheen { 0%, 100% { background-position: 100% 0; } 50% { background-position: 0 0; } }
@keyframes sb-pop { from { opacity: 0; transform: scale(.6) translateY(6px); } }
@keyframes sb-rise-in { from { opacity: 0; transform: translateY(14px); } }
@keyframes sb-row-in { from { opacity: 0; transform: translateY(60px) scale(.97); } }
@keyframes sbr-in { from { opacity: 0; transform: scale(1.04); } }
@keyframes sbr-shade { 0%, 100% { opacity: 0; } 50% { opacity: 1; } }

@media (prefers-reduced-motion: reduce) {
  .sb3d-float, .sb3d-shadow, .sb3d-aura, .sb-title, .sb-tagline span, .sb-strip-page, .sb-mini, .sb-row, .sb-contents[open] li { animation: none !important; }
  .sb3d-book, .sbr-leaf, .sbr-book, .sb3d-fan img { transition-duration: .01s !important; }
  .sb-title { color: var(--text); background: none; }
}