/* ========== Timeline Layout ========== */
.timeline-section {
  padding: 64px 0 80px;
}

.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--accent) 0%, var(--border) 30%, var(--border) 90%, transparent 100%);
  transform: translateX(-50%);
}

/* Year markers */
.timeline-year {
  position: relative;
  z-index: 10;
  margin: 56px 0 36px;
}

.timeline-year:first-child {
  margin-top: 0;
}

.year-marker {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.year-text {
  background: var(--bg);
  color: var(--accent);
  font-size: 1.8rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  padding: 8px 24px;
  position: relative;
  z-index: 2;
}

.year-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: var(--bg);
  padding: 0 12px;
}

/* Timeline items */
.timeline-item {
  position: relative;
  width: 50%;
  padding: 0 40px 40px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.timeline-item.revealed {
  opacity: 1;
  transform: translateY(0);
}

.timeline-item.right {
  margin-left: 50%;
}

.timeline-item.left {
  margin-right: 50%;
  text-align: right;
}

.timeline-item.left .timeline-card {
  margin-left: auto;
}

.timeline-item.left .tl-header {
  flex-direction: row-reverse;
}

.timeline-item.left .tl-metric {
  margin-left: auto;
  margin-right: 0;
}

/* Timeline dot */
.timeline-dot {
  position: absolute;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg);
  z-index: 5;
  box-shadow: 0 0 0 3px var(--accent-glow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.timeline-item.right .timeline-dot {
  left: -6px;
}

.timeline-item.left .timeline-dot {
  right: -6px;
}

.timeline-item:hover .timeline-dot {
  transform: scale(1.4);
  box-shadow: 0 0 0 6px var(--accent-glow);
}

/* Timeline card */
.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 22px 24px;
  max-width: 380px;
  transition: border-color var(--transition-medium), box-shadow var(--transition-medium), transform var(--transition-medium);
}

.timeline-item:hover .timeline-card {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-2px);
}

.tl-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.tl-date {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-family: "SF Mono", "Fira Code", monospace;
  letter-spacing: 0.04em;
}

.tl-cat {
  font-size: 0.68rem;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 12px;
  letter-spacing: 0.02em;
}

.tl-cat.dev       { background: var(--cat-dev-bg);       color: var(--cat-dev); }
.tl-cat.service   { background: var(--cat-service-bg);   color: var(--cat-service); }
.tl-cat.legal     { background: var(--cat-legal-bg);     color: var(--cat-legal); }
.tl-cat.research  { background: var(--cat-research-bg);  color: var(--cat-research); }
.tl-cat.content   { background: var(--cat-content-bg);   color: var(--cat-content); }
.tl-cat.finance   { background: var(--cat-finance-bg);   color: var(--cat-finance); }
.tl-cat.productivity { background: var(--cat-productivity-bg); color: var(--cat-productivity); }
.tl-cat.ops       { background: var(--cat-ops-bg);       color: var(--cat-ops); }
.tl-cat.education { background: var(--cat-education-bg); color: var(--cat-education); }

.timeline-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
  line-height: 1.4;
}

.tl-tagline {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 10px;
  opacity: 0.85;
}

.tl-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 0;
}

/* Metric highlight */
.tl-metric {
  display: inline-flex;
  flex-direction: column;
  gap: 1px;
  margin-top: 14px;
  padding: 8px 14px;
  background: rgba(99, 102, 241, 0.06);
  border: 1px solid rgba(99, 102, 241, 0.12);
  border-radius: 8px;
}

.metric-value {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.metric-label {
  font-size: 0.68rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* Timeline end */
.timeline-end {
  position: relative;
  z-index: 10;
  margin-top: 56px;
  padding-bottom: 20px;
}

.timeline-end .year-text {
  font-size: 1.4rem;
  color: var(--text-muted);
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
  .timeline::before {
    left: 20px;
  }

  .timeline-item {
    width: 100%;
    padding: 0 0 32px 48px;
    text-align: left;
  }

  .timeline-item.right {
    margin-left: 0;
  }

  .timeline-item.left {
    margin-right: 0;
    text-align: left;
  }

  .timeline-item.left .timeline-card {
    margin-left: 0;
  }

  .timeline-item.left .tl-header {
    flex-direction: row;
  }

  .timeline-item.left .tl-metric {
    margin-left: 0;
  }

  .timeline-dot {
    left: 14px !important;
    right: auto !important;
  }

  .timeline-card {
    max-width: 100%;
  }

  .year-marker {
    align-items: flex-start;
    padding-left: 48px;
  }

  .year-text {
    padding: 4px 0;
    font-size: 1.5rem;
  }

  .year-label {
    padding: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .timeline-item {
    opacity: 1;
    transform: none;
  }
}