body {
  font-family: 'Inter', sans-serif;
  margin: 0;
  background: #f5f7fa;
  color: #333;
}


.header {
  text-align: center;
  padding: 3rem 1rem;
  background-color: #ffffff;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.header h1 {
  margin-bottom: 0.5rem;
  font-size: 2.5rem;
  color: #222;
}
.header p {
  color: #666;
  font-size: 1.1rem;
}


.timeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding: 3rem 1rem;
  max-width: 960px;
  margin: auto;
}
.timeline-item {
  position: relative;
  animation: fadeInUp 1s ease forwards;
  opacity: 0;
}
.timeline-content {
  background: #fff;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  position: relative;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.timeline-content:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.1);
}
.timeline-icon {
  position: absolute;
  top: -20px;
  left: -20px;
  background: #4f46e5;
  color: #fff;
  font-weight: bold;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.timeline-content h2 {
  margin-top: 0;
  font-size: 1.5rem;
}
.timeline-content p {
  margin: 0.5rem 0 1rem;
  font-size: 1rem;
}
.timeline-content small {
  color: #999;
}

@media (min-width: 768px) {
  .timeline {
    grid-template-columns: repeat(2, 1fr);
  }
  .timeline-item:nth-child(even) {
    transform: translateY(50px);
  }
}


@keyframes fadeInUp {
  from {
    transform: translateY(30px);
    opacity: 0;
  }
  to {
    transform: translateY(0px);
    opacity: 1;
  }
}


.back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: #4f46e5;
  color: #fff;
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  font-size: 1.2rem;
  cursor: pointer;
  display: none;
  z-index: 999;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.back-to-top:hover {
  background: #3730a3;
}