:root {
  color-scheme: dark;
  --bg: #071416;
  --panel: #102326;
  --panel-light: #173136;
  --text: #f4f7f6;
  --muted: #adc0bd;
  --accent: #55d6be;
  --accent-dark: #06201c;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at 50% 0, #17434a 0, transparent 42rem),
    var(--bg);
  color: var(--text);
}

main {
  width: min(46rem, calc(100% - 2rem));
  margin: 0 auto;
  padding: 4rem 0 2.5rem;
}

header { text-align: center; }

.mark {
  width: 3.25rem;
  height: 3.25rem;
  margin: 0 auto 1rem;
  border: 2px solid var(--accent);
  border-radius: 50%;
  color: var(--accent);
  font-size: 2.25rem;
  line-height: 2.75rem;
  transform: rotate(-25deg);
}

.eyebrow {
  margin: 0 0 .45rem;
  color: var(--accent);
  font-size: .78rem;
  font-weight: 750;
  letter-spacing: .14em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2.5rem, 10vw, 4.5rem);
  letter-spacing: -.055em;
  line-height: 1;
}

.intro {
  max-width: 33rem;
  margin: 1rem auto 2.5rem;
  color: var(--muted);
  font-size: 1.1rem;
  line-height: 1.55;
}

.primary {
  padding: 2rem;
  border: 1px solid #285056;
  border-radius: 1.25rem;
  background: linear-gradient(145deg, var(--panel-light), var(--panel));
  box-shadow: 0 1.5rem 4rem #0006;
  text-align: center;
}

h2 { margin: 0; font-size: 1.45rem; }
.primary > p { color: var(--muted); }

.button {
  display: block;
  margin: 1.4rem 0 1rem;
  padding: 1rem 1.25rem;
  border-radius: .75rem;
  background: var(--accent);
  color: var(--accent-dark);
  font-size: 1.05rem;
  font-weight: 800;
  text-decoration: none;
}

.button:hover, .button:focus-visible { background: #7ce8d4; }
.note { margin: 0; font-size: .85rem; }

nav {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .8rem;
  margin-top: .8rem;
}

.card {
  min-height: 8rem;
  padding: 1.15rem;
  border: 1px solid #234349;
  border-radius: 1rem;
  background: var(--panel);
  color: var(--text);
  text-decoration: none;
}

.card:hover, .card:focus-visible { border-color: var(--accent); }
.card span { display: block; margin-bottom: .45rem; font-weight: 750; }
.card small { color: var(--muted); line-height: 1.45; }

footer {
  display: flex;
  justify-content: center;
  gap: .7rem;
  margin-top: 2rem;
  color: #78918e;
  font-size: .88rem;
}

footer a { color: var(--muted); }

@media (max-width: 38rem) {
  main { padding-top: 2.5rem; }
  .primary { padding: 1.5rem; }
  nav { grid-template-columns: 1fr; }
  .card { min-height: auto; }
  footer { flex-wrap: wrap; }
}