.timeline {
  position: relative;
  max-width: 900px;
  margin: var(--space-7) auto 0;
}

.timeline-line {
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
  transform: translateX(-50%);
}

.timeline-line-fill {
  position: absolute;
  inset: 0;
  width: 100%;
  background: linear-gradient(var(--color-accent), var(--color-accent-alt));
  transform-origin: top;
  transform: scaleY(0);
}

.timeline-milestone-wrap {
  position: relative;
  width: 50%;
  padding: 0 var(--space-6);
  margin-bottom: var(--space-6);
}

.timeline-milestone-wrap:nth-child(odd) {
  left: 0;
}

.timeline-milestone-wrap:nth-child(even) {
  left: 50%;
}

.timeline-dot {
  position: absolute;
  top: var(--space-4);
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, 0.2);
  z-index: 1;
  transition: transform 300ms ease, background 300ms ease;
}

.timeline-milestone-wrap.is-active .timeline-dot {
  background: var(--color-accent-alt);
  transform: scale(1.35);
}

.timeline-milestone-wrap:nth-child(odd) .timeline-dot {
  right: -7px;
}

.timeline-milestone-wrap:nth-child(even) .timeline-dot {
  left: -7px;
}

.timeline-milestone {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-5);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.4);
  max-height: 480px;
  overflow-y: auto;
}

.timeline-type {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 1.1rem;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(34, 211, 238, 0.12);
  border: 1px solid var(--color-accent);
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}

.timeline-milestone .year {
  font-family: var(--font-heading);
  color: var(--color-accent);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
  font-size: 1.5rem;
}

.timeline-milestone h3 {
  font-family: var(--font-heading);
  color: var(--color-fg);
  font-size: 1.9rem;
  margin-bottom: var(--space-2);
}

.timeline-milestone p,
.timeline-milestone li {
  color: var(--color-fg-muted);
  font-family: var(--font-body);
  font-size: 1.5rem;
  line-height: 1.6;
}

.timeline-milestone ul {
  margin: var(--space-2) 0 0 1.8rem;
}

.timeline-milestone li {
  margin-bottom: 0.4rem;
}

@media (max-width: 850px) {
  .timeline-line {
    left: 20px;
  }

  .timeline-milestone-wrap,
  .timeline-milestone-wrap:nth-child(even) {
    width: 100%;
    left: 0;
    padding-left: 50px;
    padding-right: 0;
  }

  .timeline-milestone-wrap:nth-child(odd) .timeline-dot,
  .timeline-milestone-wrap:nth-child(even) .timeline-dot {
    left: 13px;
    right: auto;
  }
}

@media (prefers-reduced-motion: reduce), (hover: none) {
  .timeline-milestone-wrap {
    opacity: 1 !important;
    transform: none !important;
  }

  .timeline-line-fill {
    transform: scaleY(1) !important;
  }
}