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

.timeline::before {
  content: '';
  position: absolute;
  top: 24px;
  bottom: 24px;
  left: 28px;
  width: 2px;
  background: var(--border-color);
}

.timeline-items {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.timeline-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-lg);
  position: relative;
  padding-left: 64px;
  text-align: left;
}

.timeline-node {
  position: absolute;
  left: 20px;
  top: 22px;
  width: 14px;
  height: 14px;
  background: var(--bg-primary);
  border: 3px solid var(--accent-primary);
  border-radius: 50%;
  z-index: 1;
  transition: all 0.3s ease;
}

.timeline-content {
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: var(--text-small);
  color: var(--accent-primary);
  margin-bottom: 2px;
  min-width: 110px;
  display: inline-block;
}

.timeline-title {
  font-family: var(--font-display);
  font-size: var(--text-h3);
  font-weight: 600;
  margin-bottom: var(--space-xs);
  display: inline;
}

.timeline-desc {
  color: var(--text-secondary);
  font-size: var(--text-small);
  margin-top: var(--space-xs);
}

.timeline-header {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.timeline-toggle {
  font-size: 12px;
  color: var(--accent-primary);
  cursor: pointer;
  padding: 4px 12px;
  border: 1.5px dashed var(--accent-primary);
  border-radius: 20px;
  transition: all 0.25s ease;
  white-space: nowrap;
  margin-left: var(--space-sm);
  opacity: 0.8;
  flex-shrink: 0;
}

.timeline-toggle:hover {
  background: rgba(16, 185, 129, 0.06);
  border-style: solid;
  opacity: 1;
}

.timeline-item.expanded .timeline-toggle {
  border-style: solid;
  background: rgba(16, 185, 129, 0.06);
}

.timeline-detail {
  display: none;
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transition: max-height 0.45s ease, opacity 0.3s ease, padding 0.35s ease;
  padding-top: 0;
  margin-top: 0;
}

.timeline-item.expanded .timeline-detail {
  display: block;
  max-height: 3000px;
  opacity: 1;
  padding-top: var(--space-lg);
  margin-top: var(--space-md);
  border-top: 1px solid var(--border-color);
}

.timeline-item.expanded .timeline-node {
  background: var(--accent-primary);
  box-shadow: 0 0 16px var(--accent-glow);
}

.timeline-item.expanded .timeline-content {
  border-color: var(--accent-primary);
  box-shadow: 0 2px 20px rgba(16, 185, 129, 0.08);
}

.timeline-detail .phase-narrative {
  text-align: left;
  padding: 0;
  background: none;
  border-left: none;
  border-radius: 0;
  margin: 0;
}

.timeline-detail .phase-narrative h4 {
  font-size: var(--text-h4);
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.timeline-detail .reflection-grid {
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-md);
}

.timeline-detail .reflection-card {
  padding: var(--space-md);
}

.timeline-detail .reflection-header {
  padding-bottom: var(--space-sm);
  margin-bottom: var(--space-sm);
}

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 767px) {
  .timeline {
    max-width: 100%;
    padding-left: 0;
    padding-right: 0;
  }

  .timeline::before {
    left: 18px;
  }

  .timeline-item {
    padding-left: 48px;
  }

  .timeline-node {
    left: 11px;
    top: 18px;
    width: 12px;
    height: 12px;
  }

  .timeline-content {
    padding: var(--space-md);
  }

  .timeline-detail .decision-cards,
  .timeline-detail .deliverables-grid,
  .timeline-detail .reflection-grid {
    grid-template-columns: 1fr;
  }

  .timeline-detail .reflection-card {
    padding: var(--space-md);
  }
}