:root{
  --accent:blue;
  --muted:#777;
  --bg:#f7f9fc;
  --card-bg:#fff;
  --max-width:900px;
}

*{box-sizing:border-box}
body{
  font-family:system-ui,-apple-system,Segoe UI,Roboto,"Helvetica Neue",Arial;
  background:var(--bg);
  margin:0;
  padding:2rem;
  color:#222;
}

.timeline-container{
  max-width:var(--max-width);
  margin:0 auto;
}

h1{ text-align:center; margin-bottom:1.5rem; }

/* Timeline base */
.timeline{
  position:relative;
  padding:2rem 0;
  margin:0;
}

/* center line */
.timeline::before{
  content:"";
  position:absolute;
  top:0;
  bottom:0;
  left:50%;
  width:4px;
  background:linear-gradient(#eee,var(--accent));
  transform:translateX(-50%);
  border-radius:2px;
}

/* each item */
.timeline-item{
  position:relative;
  width:50%;
  padding:1rem 2rem;
}

/* place left/right */
.timeline-item:nth-child(odd){
  left:0;
  text-align:right;
}
.timeline-item:nth-child(even){
  left:50%;
}

/* the card */
.timeline-content{
  background:var(--card-bg);
  padding:1rem;
  border-radius:8px;
  box-shadow:0 6px 18px rgba(12,20,30,0.06);
  display:inline-block;
  max-width:420px;
  position:relative;
}

/* connector circle */
.timeline-item::after{
  content:"";
  position:absolute;
  top:1.25rem;
  width:14px;
  height:14px;
  border-radius:50%;
  background:var(--card-bg);
  border:4px solid var(--accent);
  box-shadow:0 2px 6px rgba(0,0,0,0.08);
}

/* circle position depending on side */
.timeline-item:nth-child(odd)::after{
  right:-8px;
}
.timeline-item:nth-child(even)::after{
  left:-8px;
}

/* small styling for times and headings */
time{
  display:block;
  color:var(--muted);
  font-size:0.85rem;
  margin-bottom:0.25rem;
}
h3{ margin:0 0 0.5rem 0; font-size:1.05rem; }
p{ margin:0; color:#333; line-height:1.45; }

/* Responsive: stack on small screens */
@media (max-width:720px){
  .timeline::before{ left:12px; }
  .timeline-item{
    width:100%;
    padding-left:2.5rem;
    padding-right:1rem;
    margin-bottom:1.35rem;
  }
  .timeline-item:nth-child(odd),
  .timeline-item:nth-child(even){ left:0; text-align:left; }
  .timeline-item::after{ left:0; transform:translateX(-50%); top:0.75rem; }
  .timeline-content{ display:block; width:100%; }
}