*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #ffffff;
  --fg: #111111;
  --muted: #666666;
  --accent: #222222;
  --border: #e5e5e5;
  --max-w: 720px;
  --font: system-ui, -apple-system, sans-serif;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--fg);
  line-height: 1.6;
}

/* ── Navigation ── */
header {
  position: sticky;
  top: 0;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 1rem 1.5rem;
}

.brand {
  font-weight: 600;
  letter-spacing: -0.02em;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.15s;
}

nav a:hover {
  color: var(--fg);
}

/* ── Hero ── */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  min-height: 60vh;
  padding: 4rem 1.5rem;
}

.label {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
}

h1 {
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.sub {
  margin-top: 1rem;
  color: var(--muted);
  font-size: 1rem;
  max-width: 40ch;
}

/* ── Sections ── */
.section {
  padding: 4rem 1.5rem;
  border-top: 1px solid var(--border);
}

.section.alt {
  background: #fafafa;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 2rem 1.5rem;
  font-size: 0.8rem;
  color: var(--muted);
}

/* ── Responsive ── */
@media (max-width: 480px) {
  .brand {
    font-size: 0.9rem;
  }

  nav ul {
    gap: 1rem;
  }
}