.scroll-rail {
  position: fixed;
  left: 18px;
  top: 50%;
  z-index: 60;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  transform: translateY(-50%);
  color: var(--faint);
  user-select: none;
}

.scroll-rail__label {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.18em;
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}

.scroll-rail__count {
  color: var(--faint);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.04em;
}

.scroll-rail__dots {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
}

.scroll-rail__dot {
  display: block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #c9d4e3;
  box-shadow: 0 0 0 0 rgba(14, 82, 240, 0);
  transition: background 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.scroll-rail__dot:hover {
  background: #8ca6ca;
}

.scroll-rail__dot.is-active {
  background: var(--brand);
  box-shadow: 0 0 0 4px rgba(14, 82, 240, 0.1);
  transform: scale(1.2);
}

.scroll-rail__next {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--faint);
  font-family: inherit;
  font-size: 8px;
  letter-spacing: 0.04em;
  writing-mode: vertical-rl;
  cursor: pointer;
}

.scroll-rail__next span {
  color: var(--brand);
  font-family: var(--mono);
  font-size: 11px;
  animation: rail-nudge 1.8s ease-in-out infinite;
}

.scroll-rail__next:hover {
  color: var(--brand);
}

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

@media (max-width: 1199px) {
  .scroll-rail { display: none; }
}