:root {
  --bg: #f5f7fb;
  --panel: #ffffff;
  --text: #172033;
  --muted: #5f6f89;
  --accent: #2457c5;
  --line: #dce3ef;
  --soft: #eef3ff;
  --radius: 20px;
  --text-width: 720px;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 18px;
  line-height: 1.7;
}

.container {
  max-width: 1000px;
  margin: auto;
  padding: 32px 20px;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 48px;
}

.brand {
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text);
  text-decoration: none;
}

.nav {
  display: flex;
  gap: 18px;
  font-size: 0.95rem;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
}

.nav a:hover {
  color: var(--accent);
  text-decoration: underline;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.055em;
  margin: 0 0 18px;
  max-width: var(--text-width);
}

h2 {
  margin-top: 56px;
  font-size: 1.65rem;
  letter-spacing: -0.035em;
}

h3 {
  margin-top: 0;
  letter-spacing: -0.02em;
}

.lead {
  color: var(--muted);
  font-size: 1.12rem;
  max-width: var(--text-width);
}

.card {
  background: white;
  padding: 26px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  margin-top: 16px;
}

.grid {
  display: grid;
  gap: 16px;
}

@media (min-width: 700px) {
  .grid {
    grid-template-columns: 1fr 1fr;
  }
}

.button {
  display: inline-block;
  margin-top: 20px;
  padding: 12px 18px;
  background: var(--accent);
  color: white;
  border-radius: 999px;
  text-decoration: none;
  font-weight: bold;
}

.button:hover {
  filter: brightness(0.94);
}

.highlight {
  background: var(--soft);
  padding: 18px 22px;
  border-radius: 12px;
  margin-top: 18px;
  max-width: var(--text-width);
}

section > p {
  max-width: var(--text-width);
}

.footer {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.92rem;
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    margin-bottom: 34px;
  }

  .nav {
    flex-wrap: wrap;
  }
}