body {
  font-family:
    "Noto Sans",
    "Helvetica Neue",
    Ubuntu,
    "DejaVu Sans",
    sans-serif;
}

h1 {
  font-size: 167%;
  background-color: #eee;
  border-left: 6px solid #bbb;
  padding: 4px 0 0 8px;
}

h2 {
  font-size: 124%;
  background-color: #eee;
  border-left: 6px solid #bbb;
  padding: 2px 0 0 8px;
}

h3 {
  font-size: 100%;
  background-color: #eee;
}

h3::before {
  content: "\25FE"; /* ◼️ Black Medium Square */
}