.vertical-timeline-container {
  min-height: 100vh;
  background: linear-gradient(135deg, #f5f7ff 0%, #ffffff 100%);
  padding: 6rem 1rem 2rem;
  position: relative;
  color: #1a1a1a;
}

.vertical-timeline-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    linear-gradient(90deg, rgba(99, 102, 241, 0.05) 1px, transparent 1px),
    linear-gradient(rgba(99, 102, 241, 0.05) 1px, transparent 1px);
  background-size: 20px 20px;
  pointer-events: none;
  z-index: 1;
}

.timeline-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  position: relative;
  z-index: 2;
  background: linear-gradient(135deg, #6366F1 0%, #4F46E5 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.category-filters {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 2;
}

.category-filter {
  background: rgba(99, 102, 241, 0.1);
  backdrop-filter: blur(5px);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 30px;
  padding: 0.5rem 1.2rem;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  color: #4F46E5;
}

.category-filter.active {
  background: linear-gradient(135deg, #6366F1 0%, #4F46E5 100%);
  border-color: transparent;
  color: white;
}

.category-filter:hover:not(.active) {
  background: rgba(99, 102, 241, 0.2);
}

.timeline-events-list {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
  padding: 0 1rem;
}

.timeline-events-list::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(50px + 1rem);
  width: 3px;
  background: linear-gradient(to bottom, rgba(99, 102, 241, 0.1), rgba(79, 70, 229, 0.3), rgba(99, 102, 241, 0.1));
  border-radius: 1.5px;
  transform: translateX(-50%);
}

.timeline-year-separator {
  text-align: center;
  font-size: 1.6rem;
  margin: 2.5rem 0 1.5rem;
  color: #4F46E5;
  position: relative;
  z-index: 3;
  background: #f5f7ff;
  display: inline-block;
  padding: 0 1rem;
  left: 50%;
  transform: translateX(-50%);
}

.timeline-event-item {
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
  position: relative;
  margin-bottom: 2rem;
  padding-left: calc(50px + 1rem + 20px);
}

.event-date {
  position: absolute;
  left: 0;
  top: 5px;
  width: 50px;
  text-align: right;
  font-size: 0.85rem;
  color: #6b7280;
  font-weight: 500;
  white-space: nowrap;
}

.timeline-event-item::before {
  content: '';
  position: absolute;
  left: calc(50px + 1rem);
  top: 12px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: white;
  border: 3px solid #6366F1;
  transform: translateX(-50%);
  z-index: 3;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.event-cards-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  flex-grow: 1;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(8px);
  border-radius: 10px;
  border: 1px solid rgba(99, 102, 241, 0.15);
  box-shadow: 0 6px 25px rgba(99, 102, 241, 0.08);
}

.event-link {
  padding: 1rem 1.2rem;
  transition: all 0.3s ease;
  cursor: pointer;
  text-decoration: none;
  color: #1a1a1a;
  display: block;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid rgba(99, 102, 241, 0.1);
}

.event-link:last-child {
  border-bottom: none;
}

.event-link:hover {
  background: rgba(99, 102, 241, 0.05);
}

.event-content {
  padding-right: 2rem;
}

.event-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #374151;
}

.event-description {
  font-size: 0.95rem;
  line-height: 1.5;
  color: #4b5563;
  overflow: hidden;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  transition: all 0.3s ease;
}

.event-link:hover .event-description {
  -webkit-line-clamp: unset;
}

.event-arrow {
  position: absolute;
  top: 50%;
  right: 1rem;
  transform: translateY(-50%);
  font-size: 1.1rem;
  color: rgba(99, 102, 241, 0.5);
  transition: all 0.3s ease;
}

.event-link:hover .event-arrow {
  color: #4F46E5;
  transform: translate(3px, -50%);
}

.timeline-event-item.model-release::before {
  border-color: #6366F1;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.timeline-event-item.open-source::before {
  border-color: #22c55e;
  box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.1);
}

.timeline-event-item.business-industry::before {
  border-color: #F59E0B;
  box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.1);
}

.timeline-event-item.research-papers::before {
  border-color: #10B981;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.timeline-event-item.policy-regulation::before {
  border-color: #EF4444;
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.timeline-event-item.culture::before {
  border-color: #EC4899;
  box-shadow: 0 0 0 3px rgba(236, 72, 153, 0.1);
}

@media (max-width: 768px) {
  .vertical-timeline-container {
    padding: 5rem 0.5rem 1.5rem;
  }
  
  .timeline-title {
    font-size: 2rem;
    margin-bottom: 2rem;
  }
  
  .category-filters {
    gap: 0.5rem;
    margin-bottom: 2rem;
  }
  
  .category-filter {
    padding: 0.4rem 1rem;
    font-size: 0.85rem;
  }
  
  .timeline-events-list {
    padding: 0 0.5rem;
  }
  
  .timeline-events-list::before {
    left: calc(40px + 0.5rem);
  }
  
  .timeline-event-item {
    padding-left: calc(40px + 0.5rem + 15px);
    gap: 1rem;
  }
  
  .event-date {
    width: 40px;
    font-size: 0.8rem;
  }
  
  .timeline-event-item::before {
    left: calc(40px + 0.5rem);
    top: 10px;
    width: 11px;
    height: 11px;
    border-width: 2px;
  }
  
  .event-cards-container {
    gap: 0.5rem;
  }
  
  .event-link {
    padding: 0.8rem 1rem;
  }
  
  .event-title {
    font-size: 1rem;
  }
  
  .event-description {
    font-size: 0.9rem;
  }
  
  .event-arrow {
    right: 0.8rem;
  }
  
  .timeline-year-separator {
    font-size: 1.5rem;
  }
}

/* Styles for Attribution and Last Updated */
.timeline-meta-info {
  position: absolute;
  top: 6rem;
  left: 1rem;
  z-index: 2;
  text-align: left;
}

.timeline-meta-info p {
  font-size: 0.8rem;
  color: #6b7280;
  margin-bottom: 0.3rem;
  line-height: 1.3;
}

.timeline-meta-info a {
  color: #4F46E5;
  text-decoration: none;
  transition: color 0.2s ease;
}

.timeline-meta-info a:hover {
  color: #3730a3;
  text-decoration: underline;
}

/* Responsive adjustments for meta info */
@media (max-width: 768px) {
  .timeline-meta-info {
    top: 5rem;
    left: 0.5rem;
  }

  .timeline-meta-info p {
    font-size: 0.75rem;
  }
}

/* Scroll to top button */
.scroll-top-button {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background: linear-gradient(135deg, #6366F1 0%, #4F46E5 100%);
  color: white;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
  z-index: 100;
  transform: translateY(20px);
}

.scroll-top-button.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  animation: pulse 2s infinite;
}

.scroll-top-button:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 8px 15px rgba(99, 102, 241, 0.4);
  animation: none;
  background: linear-gradient(135deg, #4F46E5 0%, #3730A3 100%);
}

.scroll-top-button:active {
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(99, 102, 241, 0.3);
}

.scroll-top-button svg {
  width: 20px;
  height: 20px;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(99, 102, 241, 0.5);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(99, 102, 241, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(99, 102, 241, 0);
  }
} 