:root {
  --bg:           #0d0d1a;
  --surface:      #1a1a2e;
  --primary:      #4a6cf7;
  --primary-lt:   #7c9ef7;
  --primary-glow: rgba(74, 108, 247, 0.14);
  --border:       rgba(74, 108, 247, 0.22);
  --text:         #e8eaf6;
  --text-muted:   #8b91b5;
  --font:         'Segoe UI', 'Apple SD Gothic Neo', sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

/* ── Header ─────────────────────────────────── */
header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 2.5rem;
  background: rgba(13, 13, 26, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.logo {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: 0.1em;
}

.logo span {
  color: var(--primary-lt);
  font-weight: 400;
  font-size: 0.75rem;
  margin-left: 0.5rem;
  letter-spacing: 0.05em;
}

nav a {
  color: var(--text-muted);
  text-decoration: none;
  margin-left: 2rem;
  font-size: 0.875rem;
  transition: color 0.2s;
}

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

/* ── Section 공통 ───────────────────────────── */
.section-label {
  text-align: center;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--primary-lt);
  margin-bottom: 0.8rem;
}

.section-title {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 3rem;
  color: var(--text);
}

/* ── Footer ─────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.82rem;
}

footer .copy { margin-bottom: 0.6rem; }

footer a {
  color: var(--primary-lt);
  text-decoration: none;
  margin: 0 0.6rem;
  transition: opacity 0.2s;
}

footer a:hover { opacity: 0.75; text-decoration: underline; }

/* ── Responsive ─────────────────────────────── */
@media (max-width: 600px) {
  header { padding: 0.9rem 1.2rem; }
  nav a  { margin-left: 1rem; }
}