body {
  margin: 0;
  background: #edf1e9;
  color: #234239;
  font: 1rem/1.7 system-ui, sans-serif;
}

header, main, footer {
  margin: 0 auto;
  max-width: 65rem;
  padding-inline: clamp(1rem, 4vw, 3.5rem);
}

header {
  min-height: 4rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .85rem;
  border-bottom: 3px solid #234239;
}

header > a { font-weight: 700; }
nav { display: flex; gap: 1rem; font-size: .85rem; }
a { color: #21574a; text-underline-offset: .18em; }
h1, h2, h3 { line-height: 1.18; margin: 0; }
h1 { font-size: clamp(2.8rem, 7vw, 5rem); }
h2 { font-size: 1.55rem; }
h3 { font-size: 1.12rem; }

.lead { max-width: 42rem; padding: 3.5rem 0 2rem; }
.lead p { font-size: 1.16rem; }
.columns { padding: 2rem 0; border-top: 1px solid #99af9d; }
.columns > div { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin-top: 1.35rem; }
.columns article { background: #f8faf5; border-left: 2px solid #41715d; padding: 1.2rem; }
.columns article p { margin-bottom: 0; }
.colophon { padding: 1.8rem 0; border-top: 1px solid #99af9d; }
.colophon p { max-width: 45ch; }
footer { border-top: 1px solid #99af9d; padding-block: 1.5rem 2.5rem; }

@media (max-width: 48rem) {
  .columns > div { grid-template-columns: 1fr; }
}