/* Shared “there is more below” invitation for intro / sales landings. */

.bd-intro-scroll-cue {
  --bd-cue-accent: var(--bd-course-accent, var(--bd-intro-primary, #2a6df6));
  appearance: none;
  position: absolute;
  left: 50%;
  top: 0;
  z-index: 2;
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  font: inherit;
  color: inherit;
  cursor: pointer;
  pointer-events: none;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(calc(-100% - 0.7rem));
  transition: opacity 0.35s ease, visibility 0.35s ease, transform 0.35s ease;
}

.bd-intro-scroll-cue.is-page {
  position: fixed;
  top: auto;
  bottom: calc(1.35rem + env(safe-area-inset-bottom, 0px));
  transform: translateX(-50%);
  z-index: 90;
}

.bd-intro-scroll-cue.is-visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.bd-intro-scroll-cue.is-page.is-visible {
  transform: translateX(-50%) translateY(0);
}

.bd-intro-scroll-cue__chip {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  max-width: min(92vw, 22rem);
  padding: 0.38rem 0.85rem 0.38rem 0.38rem;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--bd-cue-accent) 26%, rgba(255, 255, 255, 0.92));
  background: color-mix(in srgb, #ffffff 86%, transparent);
  box-shadow:
    0 12px 28px rgba(15, 23, 42, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  color: var(--bd-cue-accent);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.2;
  white-space: nowrap;
}

.bd-intro-scroll-cue__orb {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(
    160deg,
    var(--bd-cue-accent),
    color-mix(in srgb, var(--bd-cue-accent) 72%, #0f172a)
  );
  box-shadow: 0 8px 16px color-mix(in srgb, var(--bd-cue-accent) 32%, transparent);
}

.bd-intro-scroll-cue__orb svg {
  display: block;
  animation: bd-cue-nudge 1.8s ease-in-out infinite;
}

.bd-intro-scroll-cue__label {
  padding-inline-end: 0.15rem;
}

.bd-intro-scroll-cue:hover .bd-intro-scroll-cue__chip,
.bd-intro-scroll-cue:focus-visible .bd-intro-scroll-cue__chip {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--bd-cue-accent) 42%, #fff);
}

.bd-intro-scroll-cue:focus-visible {
  outline: none;
}

.bd-intro-scroll-cue:focus-visible .bd-intro-scroll-cue__chip {
  box-shadow:
    0 12px 28px rgba(15, 23, 42, 0.12),
    0 0 0 4px color-mix(in srgb, var(--bd-cue-accent) 24%, transparent);
}

@keyframes bd-cue-nudge {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(3px); }
}

.bd-teaching-method {
  --bd-cue-accent: var(--primary, #4f46e5);
}

.bd-teaching-method .bd-intro-scroll-cue.is-page {
  bottom: calc(1.5rem + env(safe-area-inset-bottom, 0px));
}

#bd-intro-continue,
#bd-teaching-method,
.bd-book-intro-specs,
.bd-course-intro-stats,
.bd-intro-stats {
  scroll-margin-top: calc(var(--bd-t-header-h, 72px) + 12px);
}

@media (max-width: 640px) {
  .bd-intro-scroll-cue__chip {
    padding: 0.32rem 0.72rem 0.32rem 0.32rem;
    font-size: 0.74rem;
  }

  .bd-intro-scroll-cue__orb {
    width: 26px;
    height: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .bd-intro-scroll-cue,
  .bd-intro-scroll-cue__chip,
  .bd-intro-scroll-cue__orb svg {
    animation: none !important;
    transition: none !important;
  }

  .bd-intro-scroll-cue:hover .bd-intro-scroll-cue__chip,
  .bd-intro-scroll-cue:focus-visible .bd-intro-scroll-cue__chip {
    transform: none;
  }
}