:root {
  --emerald: #178a55;
  --emerald-dark: #116b41;
  --emerald-deep: #0b3d26;
  --emerald-tint: #f1f8f4;
  --on-emerald: #ffffff;
  --on-emerald-muted: #d3f0e0;
  --bg: #ffffff;
  --text: #12201a;
  --text-muted: #5d7267;
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-brand: "Montserrat", var(--font-body);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.5;
}

/* Brand panel */

.brand {
  background: var(--emerald);
  color: var(--on-emerald);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 48px 24px;
}

.brand-mark {
  width: min(220px, 40vw);
  height: auto;
}

.brand-name {
  margin: 24px 0 0;
  font-family: var(--font-brand);
  font-weight: 500;
  font-size: clamp(28px, 3.4vw, 44px);
  letter-spacing: 0.04em;
  line-height: 1.05;
}

.brand-tagline {
  margin: 12px 0 0;
  color: var(--on-emerald-muted);
}

/* Content */

main {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 40px;
  padding: 48px clamp(24px, 6vw, 80px);
  max-width: 640px;
  width: 100%;
}

section[hidden] {
  display: none;
}

.caption {
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--emerald);
}

.lead {
  margin: 0;
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 600;
  line-height: 1.25;
}

.note {
  margin: 12px 0 0;
  color: var(--text-muted);
}

.cards {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.card {
  background: var(--emerald-tint);
  border-radius: 10px;
  padding: 20px;
}

.card h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
}

.card p {
  margin: 2px 0 14px;
  color: var(--text-muted);
}

.btn {
  display: inline-block;
  padding: 7px 16px;
  border: 1px solid var(--emerald);
  border-radius: 6px;
  background: var(--emerald);
  color: var(--on-emerald);
  font-size: 14px;
  text-decoration: none;
}

.btn:hover {
  background: var(--emerald-dark);
  border-color: var(--emerald-dark);
}

.btn-outline {
  background: transparent;
  color: var(--emerald-dark);
}

.btn-outline:hover {
  background: var(--emerald);
  color: var(--on-emerald);
}

a:focus-visible {
  outline: 2px solid var(--emerald-deep);
  outline-offset: 2px;
}

footer {
  font-size: 14px;
  color: var(--text-muted);
}

footer p {
  margin: 0;
}

footer a {
  color: var(--emerald-dark);
}

/* 404 */

.notfound {
  grid-template-columns: minmax(0, 1fr);
}

.notfound .btn {
  margin-top: 28px;
  background: var(--on-emerald);
  border-color: var(--on-emerald);
  color: var(--emerald-dark);
}

@media (max-width: 720px) {
  body {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: auto 1fr;
  }

  .brand {
    padding: 40px 24px;
  }

  .brand-mark {
    width: 120px;
  }

  .notfound {
    grid-template-rows: 1fr;
  }

  main {
    justify-content: flex-start;
    padding: 32px 20px;
    max-width: none;
  }
}