/* ============================================================
   NEUROFLASH — Hero "Lâche ton PDF"
   Le livre/PDF chute, rebondit, déclenche une onde de choc
   et explose en cartes + nœuds. Étagère Studyflash dessous.
   Tout en transform/opacity. Coupé si prefers-reduced-motion.
   ============================================================ */

/* ---------------- Ligne de sol + flash ---------------- */
.drop__ground {
  position: absolute;
  left: 50%; top: 270px;
  width: 340px; height: 2px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, transparent, rgba(167,139,250,0.85), transparent);
  border-radius: 2px;
  z-index: 2;
}
.drop__ground::after {
  content: "";
  position: absolute; left: 50%; top: 50%;
  width: 300px; height: 80px;
  transform: translate(-50%, -50%);
  background: radial-gradient(ellipse at center, rgba(150,99,233,0.45), transparent 70%);
  filter: blur(8px);
  opacity: 0;
}
.hero__stage.impact .drop__ground::after { animation: groundFlash 0.6s var(--ease); }
@keyframes groundFlash {
  0% { opacity: 0; transform: translate(-50%, -50%) scaleX(0.4); }
  28% { opacity: 1; }
  100% { opacity: 0; transform: translate(-50%, -50%) scaleX(1.5); }
}

/* secousse de la scène à l'impact */
.hero__stage.impact { animation: stageShake 0.4s ease-out; }
@keyframes stageShake {
  0%,100% { transform: translateX(0); }
  20% { transform: translate(-4px, 2px); }
  40% { transform: translate(5px, -1px); }
  60% { transform: translate(-3px, 1px); }
  80% { transform: translate(2px, 0); }
}
@media (prefers-reduced-motion: reduce) { .hero__stage.impact { animation: none; } }

/* ---------------- Onde de choc ---------------- */
.shockwave {
  position: absolute;
  left: 50%; top: 270px;
  width: 40px; height: 40px;
  margin: -20px 0 0 -20px;
  border-radius: 50%;
  border: 2px solid rgba(124,58,237,0.7);
  opacity: 0;
  z-index: 2;
  pointer-events: none;
}
.hero__stage.impact .shockwave { animation: shock 0.66s cubic-bezier(0.2,0.7,0.3,1); }
@keyframes shock {
  0% { opacity: 0.9; transform: scale(0.3); border-width: 3px; }
  100% { opacity: 0; transform: scale(7); border-width: 0.5px; }
}

/* ---------------- Le livre / PDF hybride ---------------- */
.dropbook {
  position: absolute;
  left: 50%; top: 0;
  width: 104px; height: 132px;
  margin-left: -52px;
  border-radius: 4px 10px 10px 4px;
  background: linear-gradient(135deg, var(--violet-light), var(--indigo));
  box-shadow:
    inset -7px 0 12px -7px rgba(0,0,0,0.42),
    0 22px 46px -16px rgba(124,58,237,0.6);
  opacity: 0;
  z-index: 3;
  will-change: transform, opacity;
}
.dropbook::before {
  content: "";
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 10px;
  border-radius: 4px 0 0 4px;
  background: linear-gradient(180deg, rgba(0,0,0,0.34), rgba(0,0,0,0.12));
}
.dropbook::after {
  content: "";
  position: absolute; right: -3px; top: 6px; bottom: 6px;
  width: 7px;
  border-radius: 0 3px 3px 0;
  background: repeating-linear-gradient(180deg, #fff 0 1.6px, #d9d6e8 1.6px 3.2px);
}
.dropbook__tag {
  position: absolute;
  left: 20px; right: 9px; top: 20px;
  display: flex; flex-direction: column; gap: 6px;
}
.dropbook__badge {
  align-self: flex-start;
  font-family: var(--body);
  font-size: 10px; font-weight: 700; letter-spacing: 0.06em;
  color: #fff;
  background: rgba(0,0,0,0.30);
  border: 1px solid rgba(255,255,255,0.4);
  padding: 2px 7px; border-radius: 6px;
}
.dropbook__line { height: 6px; border-radius: 3px; background: rgba(255,255,255,0.6); }
.dropbook__line.s { width: 58%; background: rgba(255,255,255,0.42); }
.dropbook__fold {
  position: absolute; right: 7px; top: 7px;
  width: 18px; height: 18px;
  background: linear-gradient(225deg, rgba(255,255,255,0.9) 50%, transparent 50%);
  border-radius: 0 7px 0 5px;
}

/* Chute : apparition, anticipation (remontée), chute rapide, rebond, dissolution */
.dropbook.falling { animation: bookFall 2.1s cubic-bezier(0.5, 0, 0.75, 1) forwards; }
@keyframes bookFall {
  0% { transform: translateY(-24px) rotate(-9deg) scale(0.9); opacity: 0; }
  7% { transform: translateY(-24px) rotate(-9deg) scale(1); opacity: 1; }
  18% { transform: translateY(-42px) rotate(-12deg) scale(1.06); } /* anticipation */
  30% { transform: translateY(-42px) rotate(-12deg) scale(1.06); } /* suspense */
  62% { transform: translateY(150px) rotate(8deg) scale(1); } /* chute */
  70% { transform: translateY(176px) rotate(11deg) scale(1.12, 0.82); } /* impact, écrasement */
  78% { transform: translateY(140px) rotate(9deg) scale(0.92, 1.1); } /* rebond */
  86% { transform: translateY(172px) rotate(10deg) scale(1); }
  92% { transform: translateY(172px) rotate(10deg) scale(1); opacity: 1; }
  100% { transform: translateY(176px) rotate(10deg) scale(0.45); opacity: 0; } /* explose */
}
@media (prefers-reduced-motion: reduce) {
  .dropbook { opacity: 1; transform: translateY(150px); }
  .dropbook.falling { animation: none; }
}

/* ---------------- Particules : cartes + nœuds + pages ---------------- */
.spark {
  position: absolute;
  left: 50%; top: 250px;
  pointer-events: none;
  z-index: 4;
  will-change: transform, opacity;
  --dx: 0px; --dy: -120px; --r: 0deg;
  animation: sparkFly 1.15s cubic-bezier(0.16, 0.7, 0.3, 1) forwards;
}
@keyframes sparkFly {
  0% { transform: translate(-50%, -50%) translate(0,0) rotate(0deg) scale(0.35); opacity: 0; }
  14% { opacity: 1; transform: translate(-50%, -50%) translate(calc(var(--dx) * 0.2), calc(var(--dy) * 0.2)) rotate(calc(var(--r) * 0.2)) scale(1.05); }
  100% { transform: translate(-50%, -50%) translate(var(--dx), var(--dy)) rotate(var(--r)) scale(0.9); opacity: 0; }
}
.spark--card {
  width: 38px; height: 48px; margin: -24px 0 0 -19px;
  border-radius: 6px;
  background: #ffffff;
  border: 1px solid rgba(124,58,237,0.18);
  box-shadow: 0 12px 24px -8px rgba(124,58,237,0.45);
  overflow: hidden;
}
.spark--card i {
  position: absolute; left: 6px; right: 6px; height: 4px; border-radius: 2px;
  background: rgba(99,102,241,0.4);
}
.spark--card i:nth-child(1) { top: 9px; }
.spark--card i:nth-child(2) { top: 18px; width: 62%; }
.spark--card i:nth-child(3) { top: 27px; background: rgba(52,211,153,0.6); width: 46%; }
.spark--dot {
  width: 12px; height: 12px; margin: -6px 0 0 -6px;
  border-radius: 50%;
  background: radial-gradient(circle, #fff, var(--violet-light) 55%, transparent 72%);
  box-shadow: 0 0 16px 4px rgba(150,99,233,0.85);
}

/* ---------------- Étagère qui défile (hommage Studyflash) ---------------- */
.shelf__track {
  display: flex;
  align-items: flex-end;
  gap: 30px;
  width: max-content;
  animation: shelfScroll 48s linear infinite;
}
.hero__shelf:hover .shelf__track { animation-play-state: paused; }
@keyframes shelfScroll { to { transform: translateX(-50%); } }
@media (prefers-reduced-motion: reduce) { .shelf__track { animation: none; } }

/* Carte "deck" par matière (inspirée des paquets de révision) :
   cartes empilées qui dépassent derrière + panneau couleur + icône matière. */
.cover { width: 140px; flex: none; padding-top: 14px; }
.cover__deck { position: relative; }
/* cartes empilées qui dépassent derrière (effet paquet/dossier) */
.cover__deck::before,
.cover__deck::after {
  content: "";
  position: absolute; left: 50%; top: -8px;
  width: 82%; height: 26px;
  transform: translateX(-50%);
  border-radius: 12px 12px 0 0;
  background: #fff;
  border: 1px solid var(--border);
}
.cover__deck::before { top: -13px; width: 66%; opacity: 0.6; }
.cover__card {
  position: relative;
  height: 158px;
  border-radius: 16px;
  overflow: hidden;
  padding: 14px 14px 13px;
  display: flex;
  flex-direction: column;
  background: linear-gradient(165deg, color-mix(in oklab, var(--accent, var(--violet-light)) 24%, #fff), #fff 78%);
  border: 1px solid color-mix(in oklab, var(--accent, var(--violet-light)) 32%, var(--border));
  box-shadow: 0 18px 30px -20px rgba(28,18,60,0.55), inset 0 1px 0 rgba(255,255,255,0.7);
}
.cover__tag {
  align-self: flex-start;
  font-family: var(--body); font-size: 8.5px; font-weight: 700;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent, var(--violet-light));
  background: rgba(255,255,255,0.72);
  border: 1px solid color-mix(in oklab, var(--accent, var(--violet-light)) 38%, transparent);
  padding: 3px 8px; border-radius: 999px;
}
.cover__icon {
  position: absolute; right: -10px; bottom: -10px;
  width: 70px; height: 70px;
  color: var(--accent, var(--violet-light));
  opacity: 0.20;
}
.cover__title {
  margin-top: auto; position: relative; z-index: 1;
  font-family: var(--display); font-weight: 700; font-size: 0.98rem;
  letter-spacing: -0.02em; line-height: 1.05;
  color: var(--text);
}

@media (max-width: 640px) {
  .drop__ground { top: 226px; }
  .shockwave { top: 226px; }
  .shelf__track { gap: 18px; }
  .cover { width: 116px; }
  .cover__card { height: 138px; }
}