body { overflow-x: clip; }

.hero-stack { position: relative; }

.scene {
  --hdr: 72px;
  --tab: 0px;
  position: relative;
  height: 190vh;
  height: 190svh;
}
.scene-stick {
  position: sticky;
  top: var(--hdr);
  height: calc(100vh - var(--hdr));
  height: calc(100svh - var(--hdr));
  min-height: 520px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}
.scene-stick::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 38%;
  background: linear-gradient(to top, var(--bg) 6%, color-mix(in srgb, var(--bg) 60%, transparent) 46%, transparent 100%);
  pointer-events: none;
}
.scene-gl {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: pan-y;
}
.scene-copy {
  position: relative;
  z-index: 1;
  width: min(780px, 100% - 40px);
  margin-inline: auto;
  padding-block-end: calc(var(--tab) + clamp(26px, 5vh, 56px));
  text-align: center;
}
.scene-copy h1 {
  font-size: clamp(28px, 4.2vw, 50px);
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: -.02em;
  text-wrap: balance;
}
.scene-copy .lead {
  margin: 14px auto 0;
  max-width: 52ch;
  color: var(--mute);
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.85;
}
.scene-copy .cta {
  margin-top: 22px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}
.scene-copy .cta .btn { min-width: 148px; }

.scene-hint {
  position: absolute;
  inset-inline-start: 50%;
  bottom: calc(var(--tab) + 8px);
  z-index: 1;
  width: 2px;
  height: 28px;
  margin-inline-start: -1px;
  border-radius: 2px;
  background: linear-gradient(to bottom, transparent, var(--accent-2));
  transform-origin: top;
  animation: sceneHint 1.8s ease-in-out infinite;
  pointer-events: none;
  transition: opacity .3s;
}
.scene[data-s="1"] .scene-hint { animation: none; opacity: 0; }

.quick-hero {
  width: min(720px, 100% - 40px);
  margin: 0 auto;
  padding-block: 28px 44px;
}

@keyframes sceneHint {
  0%, 100% { transform: scaleY(.3); opacity: .4; }
  50% { transform: scaleY(1); opacity: 1; }
}

@media (max-width: 879px) {
  .scene { --tab: 72px; height: 175vh; height: 175svh; }
  .scene-copy .cta { display: grid; grid-template-columns: 1fr 1fr; }
  .scene-copy .cta .btn { min-width: 0; width: 100%; padding-inline: 12px; }
}

@media (max-height: 640px) {
  .scene-copy .lead { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .scene-hint { animation: none; opacity: .7; }
}
/* حالت‌های سه‌بعدی سبک: بدون اسکرول‌انیمیشن، ارتفاع ثابت */
.scene.flat { height: auto; }
.scene.flat .scene-stick {
  position: relative;
  top: auto;
  height: min(84vh, 740px);
  height: min(84svh, 740px);
  min-height: 480px;
}
.scene.flat .scene-hint { display: none; }
.scene.flat .scene-gl { cursor: grab; }
.scene[data-mode="globe"] .scene-gl:active { cursor: grabbing; }
.scene.flat.is-off .scene-stick {
  height: auto;
  min-height: 0;
  padding-block-start: clamp(56px, 13vh, 130px);
}
.scene.flat.is-off .scene-stick::after { display: none; }
@media (max-width: 879px) {
  .scene.flat { height: auto; }
  .scene.flat .scene-stick { height: min(80svh, 640px); min-height: 440px; }
  .scene.flat.is-off .scene-stick { height: auto; min-height: 0; }
}