/* ── Sticky header ────────────────────────────────────────────────────────── */
header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  transition:
    background var(--transition-md),
    backdrop-filter var(--transition-md),
    border-bottom var(--transition-md);
  border-bottom: 1px solid transparent;
}

header.scrolled {
  background: rgba(15, 23, 41, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

/* ── Nav layout ───────────────────────────────────────────────────────────── */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* ── Logo ─────────────────────────────────────────────────────────────────── */
.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--white);
  text-decoration: none;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--indigo);
  flex-shrink: 0;
  animation: pulseDot 2.5s ease-in-out infinite;
}

/* ── Desktop links ────────────────────────────────────────────────────────── */
.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  color: var(--gray);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition);
}

.nav-links a:hover {
  color: var(--white);
}

.nav-cta {
  background: var(--indigo);
  color: var(--white) !important;
  padding: 8px 20px;
  border-radius: 8px;
  transition: background var(--transition) !important;
}

.nav-cta:hover {
  background: var(--indigo-light) !important;
}

/* ── Hamburger ────────────────────────────────────────────────────────────── */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Mobile dropdown ──────────────────────────────────────────────────────── */
.mobile-menu {
  display: none;
  flex-direction: column;
  background: rgba(15, 23, 41, 0.97);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid var(--border);
  padding: 16px 24px 24px;
}

.mobile-menu a {
  color: var(--gray);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  transition: color var(--transition);
}

.mobile-menu a:last-child {
  border-bottom: none;
}

.mobile-menu a:hover {
  color: var(--white);
}

.mobile-menu.open {
  display: flex;
}

/* ── Responsive ───────────────────────────────────────────────────────────── */
@media (max-width: 720px) {
  .nav-links  { display: none; }
  .hamburger  { display: flex; }
}