/* /books/ — pure-CSS 3D books (page-books.php). Brand: navy + gold + cyan. No WebGL/libs. */
.bk-page{padding:110px 0 4rem;overflow-x:clip}
.bk-hero{text-align:center;max-width:760px;margin-bottom:clamp(1.5rem,4vw,2.5rem)}
.bk-hero h1{font-size:clamp(1.9rem,5vw,2.8rem);margin:.2rem 0 .6rem;background:linear-gradient(90deg,var(--gold2),var(--gold) 45%,var(--cyan));-webkit-background-clip:text;background-clip:text;color:transparent}
.bk-lead{color:var(--muted);font-size:clamp(.98rem,2.4vw,1.1rem);line-height:1.95;margin:0 auto}
.bk-list{display:grid;gap:clamp(1.2rem,3vw,2rem);grid-template-columns:repeat(auto-fill,minmax(min(100%,330px),1fr))}
.bk-empty{padding:2rem;text-align:center;color:var(--muted);border-radius:var(--r,20px)}
.bk-card{position:relative;display:grid;gap:1rem;border:1px solid var(--line);border-radius:var(--r,22px);padding:clamp(1rem,3vw,1.6rem);
  background:radial-gradient(90% 60% at 50% 0%,rgba(85,211,255,.10),transparent 60%),linear-gradient(180deg,rgba(255,255,255,.045),rgba(255,255,255,.015));overflow:hidden}
.bk-list[data-count="1"]{grid-template-columns:1fr}
@media (min-width:860px){.bk-list[data-count="1"] .bk-card{grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);align-items:center;gap:2.5rem;padding:2.2rem 2.4rem}}

/* ---- stage ---- */
.bk-stage{position:relative;display:grid;place-items:center;padding:1.4rem 0 2.2rem;isolation:isolate}
.bk-stage::before{content:"";position:absolute;inset:6% 8% 18%;z-index:-1;border-radius:50%;filter:blur(36px);opacity:.55;
  background:radial-gradient(closest-side,rgba(47,139,255,.55),transparent),radial-gradient(40% 40% at 70% 70%,rgba(242,196,109,.45),transparent)}
.bk-floor{position:absolute;bottom:.9rem;left:50%;width:min(86%,360px);height:46px;transform:translateX(-50%);z-index:-1;border-radius:50%;
  background:radial-gradient(closest-side,rgba(0,0,0,.75),rgba(0,0,0,0));}
.bk-floor::after{content:"";position:absolute;inset:auto 6% -6px;height:2px;border-radius:2px;background:linear-gradient(90deg,transparent,rgba(242,196,109,.75),rgba(85,211,255,.6),transparent);box-shadow:0 0 18px rgba(242,196,109,.45)}

/* ---- 3D book ---- */
.bk-scene{--w:clamp(176px,52vw,270px);--h:calc(var(--w) * 1.423);--t:34px;--ry:-34deg;--rx:6deg;
  perspective:900px;perspective-origin:50% 40%;width:calc(var(--w) + 90px);height:calc(var(--h) + 40px);display:grid;place-items:center;cursor:pointer;outline:none;
  -webkit-tap-highlight-color:transparent;animation:bk-float 6s ease-in-out infinite}
.bk-scene:focus-visible{outline:2px solid var(--gold);outline-offset:6px;border-radius:16px}
@keyframes bk-float{50%{translate:0 -9px}}
.bk{position:relative;width:var(--w);height:var(--h);transform-style:preserve-3d;
  transform:rotateX(calc(var(--rx) - var(--py,0) * 12deg)) rotateY(calc(var(--ry) + var(--px,0) * 24deg));transition:transform .9s var(--ease)}
.bk-scene.is-open{--ry:6deg;--rx:4deg}
.bk-face,.bk-cover,.bk-cover-front,.bk-cover-in{position:absolute;top:0;left:0}
.bk-back{width:var(--w);height:var(--h);transform:rotateY(180deg) translateZ(calc(var(--t) / 2));border-radius:4px 12px 12px 4px;display:grid;place-items:end center;padding-bottom:1.2rem;
  background:radial-gradient(90% 60% at 80% 10%,rgba(85,211,255,.25),transparent 60%),linear-gradient(160deg,#0f1d57,#060b26);border:1px solid rgba(242,196,109,.35);backface-visibility:hidden}
.bk-back span{font-size:.72rem;color:rgba(255,227,163,.75)}
/* spine on the right (Persian binding) */
.bk-spine{width:var(--t);height:var(--h);left:calc(var(--w) / 2 - var(--t) / 2);transform:rotateY(90deg) translateZ(calc(var(--w) / 2));
  display:flex;flex-direction:column;align-items:center;justify-content:space-between;padding:.9rem 0 .7rem;overflow:hidden;
  background:linear-gradient(90deg,#050a22,#13246a 45%,#0a1440);border-block:1px solid rgba(242,196,109,.5);
  box-shadow:inset 0 0 0 1px rgba(242,196,109,.18),inset 3px 0 6px rgba(0,0,0,.6),inset -3px 0 6px rgba(0,0,0,.6)}
.bk-spine b{writing-mode:vertical-rl;font-size:calc(var(--t) * .42);font-weight:800;color:var(--gold2);white-space:nowrap;letter-spacing:.02em;max-height:78%;overflow:hidden;text-overflow:ellipsis}
.bk-spine img{width:calc(var(--t) * .55);height:auto;opacity:.85}
/* page block: left edge, top, bottom */
.bk-edge{width:calc(var(--t) - 2px);height:calc(var(--h) - 8px);top:4px;left:calc(var(--w) / 2 - var(--t) / 2 + 1px);transform:rotateY(-90deg) translateZ(calc(var(--w) / 2 - 4px));
  background:repeating-linear-gradient(90deg,#f6f0e2 0 1px,#ddd2bb 1px 2px),#efe7d4;box-shadow:inset 0 0 8px rgba(120,95,50,.45)}
.bk-top,.bk-bottom{width:calc(var(--w) - 8px);height:calc(var(--t) - 2px);left:2px;top:calc(var(--h) / 2 - var(--t) / 2 + 1px);
  background:repeating-linear-gradient(0deg,#f6f0e2 0 1px,#ddd2bb 1px 2px),#efe7d4;box-shadow:inset 0 0 8px rgba(120,95,50,.4)}
.bk-top{transform:rotateX(90deg) translateZ(calc(var(--h) / 2 - 4px))}
.bk-bottom{transform:rotateX(-90deg) translateZ(calc(var(--h) / 2 - 4px))}
/* first page (visible when the cover opens) */
.bk-paper{width:calc(var(--w) - 8px);height:calc(var(--h) - 8px);top:4px;left:2px;transform:translateZ(calc(var(--t) / 2 - 2px));padding:14% 40% 14% 9%;
  background:linear-gradient(90deg,#efe6d1,#faf6ec 18%,#fbf8f0);color:#2b2b3a;display:flex;flex-direction:column;justify-content:center;gap:.8rem;text-align:center;border-radius:2px 8px 8px 2px}
.bk-paper p{margin:0;font-size:clamp(.72rem,2.6vw,.86rem);line-height:2}
.bk-paper small{font-size:.7rem;color:#9a7330;font-weight:700}
/* hinged front cover (hinge on the right edge) */
.bk-cover{width:var(--w);height:var(--h);transform-style:preserve-3d;transform-origin:100% 50%;transform:translateZ(calc(var(--t) / 2)) rotateY(0deg);transition:transform .9s var(--ease)}
.bk-scene.is-open .bk-cover{transform:translateZ(calc(var(--t) / 2)) rotateY(58deg)}
.bk-cover-front,.bk-cover-in{width:100%;height:100%;border-radius:4px 12px 12px 4px;overflow:hidden;backface-visibility:hidden}
.bk-cover-front{background:#0b1440;box-shadow:inset -4px 0 6px rgba(0,0,0,.35),0 0 0 1px rgba(242,196,109,.35)}
.bk-img{width:100%;height:100%;object-fit:cover;display:block}
.bk-noimg{display:grid;place-items:center;height:100%;padding:1rem;text-align:center;font-weight:800;color:var(--gold2)}
.bk-gloss{position:absolute;inset:0;pointer-events:none;mix-blend-mode:screen;
  background:linear-gradient(calc(115deg + var(--px,0) * 40deg),rgba(255,255,255,0) 35%,rgba(255,255,255,.22) 48%,rgba(255,255,255,0) 62%);transition:background .3s}
.bk-cover-front::after{content:"";position:absolute;top:0;bottom:0;right:7px;width:2px;background:linear-gradient(180deg,transparent,rgba(0,0,0,.35),transparent)}
.bk-cover-in{transform:rotateY(180deg);background:linear-gradient(270deg,#101c55,#0a1238);box-shadow:inset 0 0 0 1px rgba(242,196,109,.25)}

/* ---- info ---- */
.bk-info{display:flex;flex-direction:column;gap:.75rem;min-width:0}
.bk-badge{align-self:flex-start;display:inline-flex;align-items:center;gap:.4rem;font-size:.8rem;font-weight:800;padding:.3rem .85rem;border-radius:999px;color:#1a1204;
  background:linear-gradient(135deg,var(--gold2),var(--gold) 55%,var(--gold-d));box-shadow:0 8px 22px -10px rgba(242,196,109,.7)}
.bk-badge::before{content:"";width:8px;height:8px;border-radius:50%;background:#1a1204;opacity:.55}
.bk-info h2{font-size:clamp(1.35rem,3.6vw,1.9rem);line-height:1.5;margin:0}
.bk-blurb{margin:0;color:#d7ddf0;line-height:2}
.bk-points{margin:.1rem 0}
.bk-price{margin:.3rem 0 0;display:flex;align-items:baseline;gap:.4rem;flex-wrap:wrap}
.bk-price b{font-size:clamp(1.4rem,3.4vw,1.75rem);font-weight:900;color:var(--gold2)}
.bk-price small{color:var(--muted)}.bk-price del{color:var(--muted);font-size:.95rem}
.bk-cta{margin-top:.3rem}
.bk-hint{position:absolute;bottom:-.2rem;left:0;right:0;margin:0;text-align:center;font-size:.75rem;color:var(--muted)}
@media (hover:hover) and (pointer:fine){.bk-hint{display:none}}
@media (max-width:520px){.bk-cta{display:grid;grid-template-columns:1fr 1fr;gap:.6rem}.bk-cta .btn{justify-content:center;text-align:center}}

@media (prefers-reduced-motion:reduce){
  .bk-scene{animation:none}
  .bk,.bk-cover,.bk-gloss{transition:none}
}