.tl-filter-bar {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin: 0 auto 2rem;
  max-width: 900px;
}
.tl-filter-btn {
  padding: 0.3rem 0.85rem;
  border-radius: 9999px;
  border: 1px solid var(--color-border, #d4d1ca);
  background: var(--color-surface, #f9f8f5);
  color: var(--color-text-muted, #7a7974);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background 180ms, color 180ms, border-color 180ms;
}
.tl-filter-btn:hover {
  background: var(--color-surface-offset, #f3f0ec);
  color: var(--color-text, #28251d);
}
.tl-filter-btn.active {
  background: var(--color-primary, #01696f);
  color: #fff;
  border-color: var(--color-primary, #01696f);
}

.timeline-item {
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.55s cubic-bezier(0.175, 0.885, 0.32, 1.275),
              transform 0.55s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
@media (prefers-reduced-motion: reduce) {
  .timeline-item {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .timeline-item .timeline-dot,
  .timeline-item .timeline-line {
    opacity: 1;
    transition: none;
  }
}
.timeline-item.is-visible {
  opacity: 1;
  transform: translateY(0);
}
.timeline-item .timeline-dot,
.timeline-item .timeline-line {
  opacity: 0;
  transition: opacity 0.4s ease-in 0.25s;
}
.timeline-item.is-visible .timeline-dot,
.timeline-item.is-visible .timeline-line {
  opacity: 1;
}
.timeline-item.tl-hidden {
  display: none;
}

.timeline-item[data-type="paper"] .timeline-dot {
  background: var(--color-primary, #01696f);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--color-primary, #01696f) 20%, transparent);
}
.timeline-item[data-type="blog"] .timeline-dot {
  background: var(--color-gold, #d19900);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--color-gold, #d19900) 18%, transparent);
  width: 0.6rem !important;
  height: 0.6rem !important;
}
.timeline-item[data-type="milestone"] .timeline-dot {
  background: var(--color-orange, #da7101);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--color-orange, #da7101) 22%, transparent);
}
.timeline-item[data-type="code"] .timeline-dot {
  background: var(--color-blue, #5591c7);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--color-blue, #5591c7) 20%, transparent);
  width: 0.65rem !important;
  height: 0.65rem !important;
}

.tl-badge {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 0.15rem 0.5rem;
  border-radius: 9999px;
  margin-bottom: 0.3rem;
}
.tl-badge.paper     { background: color-mix(in srgb, var(--color-primary, #01696f) 15%, transparent); color: var(--color-primary, #01696f); }
.tl-badge.blog      { background: color-mix(in srgb, var(--color-gold, #d19900) 15%, transparent);    color: #9a6f00; }
.tl-badge.milestone { background: color-mix(in srgb, var(--color-orange, #da7101) 15%, transparent);  color: var(--color-orange, #da7101); }
.tl-badge.code      { background: color-mix(in srgb, var(--color-blue, #5591c7) 15%, transparent);    color: var(--color-blue, #5591c7); }

.tl-value-chip {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.15rem 0.55rem;
  border-radius: 9999px;
  background: color-mix(in srgb, var(--color-success, #437a22) 12%, transparent);
  color: var(--color-success, #437a22);
  margin-left: 0.4rem;
  vertical-align: middle;
}

.tl-dl-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.4rem 0 0.2rem;
}
.tl-dl-chip {
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0.12rem 0.5rem;
  border-radius: 9999px;
  border: 1px solid var(--color-border, #d4d1ca);
  background: var(--color-surface-offset, #f3f0ec);
  color: var(--color-text-muted, #7a7974);
}
.tl-dl-chip.total  { color: var(--color-blue, #5591c7); border-color: color-mix(in srgb, var(--color-blue, #5591c7) 35%, transparent); background: color-mix(in srgb, var(--color-blue, #5591c7) 8%, transparent); }
.tl-dl-chip.recent { color: var(--color-success, #437a22); border-color: color-mix(in srgb, var(--color-success, #437a22) 35%, transparent); background: color-mix(in srgb, var(--color-success, #437a22) 8%, transparent); }

.tl-drawer {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}
@media (prefers-reduced-motion: reduce) {
  .tl-drawer { transition: none; }
}
.tl-drawer.open { max-height: 600px; }
.tl-drawer-inner {
  padding: 0.75rem 0 0.5rem;
  font-size: 0.88rem;
  color: var(--color-text-muted, #7a7974);
  line-height: 1.6;
}
.tl-drawer-inner ul {
  padding-left: 1.1rem;
  margin: 0.4rem 0 0.6rem;
}
.tl-drawer-inner li { margin-top: 0.3rem; }
.tl-toggle {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--color-primary, #01696f);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  margin-top: 0.3rem;
  letter-spacing: 0.02em;
}
.tl-toggle:hover { text-decoration: underline; }

.sponsor-strip {
  max-width: 900px;
  margin: 3rem auto 2rem;
  padding: 1.5rem 2rem;
  background: color-mix(in srgb, var(--color-primary, #01696f) 7%, var(--color-surface, #f9f8f5));
  border: 1px solid color-mix(in srgb, var(--color-primary, #01696f) 25%, transparent);
  border-radius: 1rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.2rem;
}
.sponsor-strip-stats {
  font-size: 0.82rem;
  color: var(--color-text-muted, #7a7974);
  line-height: 1.7;
}
.sponsor-strip-stats strong {
  color: var(--color-text, #28251d);
  font-size: 0.95rem;
  display: block;
  margin-bottom: 0.3rem;
}
.stat-pill {
  display: inline-block;
  background: var(--color-surface, #f9f8f5);
  border: 1px solid var(--color-border, #d4d1ca);
  border-radius: 9999px;
  padding: 0.15rem 0.6rem;
  font-size: 0.72rem;
  font-weight: 600;
  margin: 0.15rem 0.15rem 0 0;
  color: var(--color-text, #28251d);
}
.sponsor-strip-cta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.6rem;
}
.sponsor-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--color-primary, #01696f);
  color: #fff;
  text-decoration: none;
  padding: 0.55rem 1.25rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 700;
  transition: opacity 180ms;
}
.sponsor-btn:hover { opacity: 0.85; }
@media (max-width: 600px) {
  .sponsor-strip { flex-direction: column; align-items: flex-start; }
  .sponsor-strip-cta { align-items: flex-start; }
}

.sponsor-strip-pills {
  margin-top: 0.5rem;
}