:root {
  --background: #f7f7f4;
  --surface: #ffffff;
  --text: #1f2933;
  --muted: #5f6b7a;
  --border: #d9ded7;
  --accent: #1f5f5b;
  --accent-dark: #174845;
  --max-width: 1040px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--background);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  background: rgba(247, 247, 244, 0.95);
  border-bottom: 1px solid var(--border);
}

.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  font-weight: 700;
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 20px;
  font-size: 15px;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.hero {
  padding: 88px 0 72px;
  max-width: 820px;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 24px;
  font-size: clamp(42px, 7vw, 72px);
  line-height: 1.02;
  letter-spacing: -0.04em;
}

h2 {
  margin: 0 0 20px;
  font-size: 32px;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h3 {
  margin: 0 0 10px;
  font-size: 20px;
  line-height: 1.3;
}

p {
  margin: 0 0 18px;
}

.hero-text {
  max-width: 760px;
  font-size: 20px;
  color: var(--muted);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.button {
  display: inline-block;
  padding: 12px 18px;
  border-radius: 999px;
  font-weight: 700;
  border: 1px solid var(--accent);
}

.button.primary {
  background: var(--accent);
  color: #ffffff;
}

.button.primary:hover {
  background: var(--accent-dark);
  text-decoration: none;
}

.button.secondary {
  color: var(--accent);
  background: transparent;
}

.button.secondary:hover {
  background: #eef4f3;
  text-decoration: none;
}

.section {
  padding: 56px 0;
  border-top: 1px solid var(--border);
}

.section > p {
  max-width: 760px;
  font-size: 18px;
  color: var(--muted);
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 28px;
}

.topic-card,
.article-list article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 24px;
}

.topic-card p,
.article-list p {
  color: var(--muted);
}

.article-list {
  display: grid;
  gap: 18px;
  margin-top: 28px;
  max-width: 820px;
}

.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 40px;
  padding: 28px 20px;
  color: var(--muted);
  text-align: center;
  font-size: 14px;
}

@media (max-width: 720px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    flex-wrap: wrap;
    gap: 14px;
  }

  .hero {
    padding: 64px 0 52px;
  }

  .hero-text {
    font-size: 18px;
  }

  .topic-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 44px 0;
  }
}

@media (max-width: 480px) {
  main {
    padding: 0 18px;
  }

  .nav {
    padding: 18px;
  }

  h1 {
    font-size: 40px;
  }

  h2 {
    font-size: 28px;
  }

  .button {
    width: 100%;
    text-align: center;
  }
}