/* ============================================================
   navbar.css — Sticky Navigation Bar
   ============================================================ */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--navbar-height);
  background: transparent;
  transition:
    background var(--transition-base),
    backdrop-filter var(--transition-base),
    border-color var(--transition-base);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(0, 0, 0, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--color-border);
}

/* ─── Inner layout ─── */
.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* ─── Logo ─── */
.navbar__logo {
  font-size: var(--fs-2xl);
  font-weight: var(--fw-bold);
  color: var(--color-text-primary);
  letter-spacing: -0.03em;
  transition: opacity var(--transition-fast);
  flex-shrink: 0;
}

.navbar__logo span {
  color: var(--color-accent);
}

.navbar__logo:hover {
  opacity: 0.85;
}

/* ─── Nav Links ─── */
.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  list-style: none;
}

.nav-link {
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  position: relative;
  padding-bottom: 2px;
  transition: color var(--transition-fast);
}

/* Underline indicator */
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: var(--radius-full);
  transition: width var(--transition-base);
}

.nav-link:hover {
  color: var(--color-text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-link.active {
  color: var(--color-accent);
}

/* ─── Hamburger (mobile) ─── */
.navbar__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  padding: 6px 4px;
  cursor: pointer;
  background: none;
  border: none;
  z-index: 1100;
}

.navbar__hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-fast);
  transform-origin: center;
}

/* Hamburger → X animation */
.navbar__hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.navbar__hamburger.open span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.navbar__hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ─── Mobile Responsive ─── */
@media (max-width: 768px) {
  .navbar__hamburger {
    display: flex;
  }

  .navbar__links {
    display: none;
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.97);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-xl);
    padding: var(--space-xl);
  }

  .navbar__links.open {
    display: flex;
  }

  .nav-link {
    font-size: var(--fs-xl);
    font-weight: var(--fw-semibold);
  }
}