body {
  font-family: Arial, sans-serif;
  margin: 24px;
  line-height: 1.6;
}
h1 { color: #164aa5; }
.intro { font-size: 20px; }
.notice {
  background-color: #edf3ff;
  border-left: 4px solid #164aa5;
  padding: 12px;
}