/* ============================================
   NAVIGATION SYSTEM — 45black.tech
   Header, Nav Links, Mobile Menu
   ============================================ */

/* ============================================
   HEADER & NAV CONTAINER
   ============================================ */

header[role="banner"] {
  min-height: var(--nav-height);
  padding: var(--space-md) 0;
}

nav[role="navigation"] {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-md);
  min-height: var(--touch-target-min);
}

/* ============================================
   LOGO
   ============================================ */

.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: var(--font-weight-bold);
  font-size: 1.375rem;
  color: var(--brand-primary);
  text-decoration: none;
  letter-spacing: var(--letter-spacing-tight);
  transition: var(--transition-colors);
}

.logo:hover {
  color: var(--brand-secondary);
  transform: translateX(2px);
}

.logo:focus {
  outline: var(--focus-ring-width) var(--focus-ring-style) var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
  border-radius: var(--border-radius-base);
}

/* Ghost vowel treatment (blkltr branding) */
.logo .ghost-vowel {
  font-weight: var(--font-weight-normal);
  color: var(--color-cool-silver);
  opacity: 0.75;
  transition: var(--transition-opacity);
}

.logo:hover .ghost-vowel {
  opacity: 1;
  color: var(--brand-secondary);
}

/* Logo with SVG icon */
.logo-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

/* ============================================
   DESKTOP NAVIGATION LINKS
   ============================================ */

.nav-links {
  display: flex;
  align-items: center;
  gap: 0;
  margin-left: auto;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--touch-target-min);
  min-width: var(--touch-target-min);
  padding: 0 var(--space-md);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--border-radius-base);
  position: relative;
  transition: var(--transition-all);
}

/* Animated underline on hover */
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 80%;
  height: 2px;
  background: var(--brand-primary);
  border-radius: 2px;
  transition: transform var(--transition-base);
}

.nav-links a:hover {
  background: var(--bg-secondary);
  color: var(--brand-primary);
}

.nav-links a:hover::after {
  transform: translateX(-50%) scaleX(1);
}

.nav-links a:focus {
  outline: var(--focus-ring-width) var(--focus-ring-style) var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

/* Current Page Indicator */
.nav-links a[aria-current="page"] {
  font-weight: var(--font-weight-semibold);
  color: var(--brand-primary);
  background: rgba(27, 77, 62, 0.05);
}

.nav-links a[aria-current="page"]::after {
  transform: translateX(-50%) scaleX(1);
}

/* ============================================
   MOBILE MENU TOGGLE (HAMBURGER)
   ============================================ */

.nav-toggle {
  display: none; /* Hidden on desktop */
  align-items: center;
  justify-content: center;
  margin-left: auto;
  min-height: var(--touch-target-min);
  min-width: var(--touch-target-min);
  padding: 0;
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--brand-primary);
  border-radius: var(--border-radius-base);
  transition: var(--transition-colors);
}

.nav-toggle:hover {
  background: var(--bg-secondary);
}

.nav-toggle:focus {
  outline: var(--focus-ring-width) var(--focus-ring-style) var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

.nav-toggle svg {
  display: block;
  width: 24px;
  height: 24px;
}

/* Icon states */
.nav-toggle .icon-menu {
  display: block;
}

.nav-toggle .icon-close {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-menu {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-close {
  display: block;
}

/* ============================================
   MOBILE NAVIGATION (768px and below)
   ============================================ */

@media (max-width: 768px) {
  header[role="banner"] {
    min-height: var(--nav-height-mobile);
    padding: var(--space-sm) 0;
  }

  /* Show hamburger menu */
  .nav-toggle {
    display: inline-flex;
  }

  /* Hide desktop nav links by default */
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg-primary);
    border-bottom: var(--border-width-1) solid var(--border-default);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    padding: var(--space-xs) 0;
    z-index: var(--z-dropdown);
    margin-left: 0;
  }

  /* Show nav when open class is added (via JavaScript) */
  .nav-links.open {
    display: flex;
  }

  /* Mobile nav link styles */
  .nav-links a {
    min-height: 48px;
    min-width: unset;
    padding: var(--space-xs) var(--space-md);
    border-radius: 0;
    justify-content: flex-start;
    border-bottom: var(--border-width-1) solid var(--border-light);
  }

  .nav-links a:last-child {
    border-bottom: none;
  }

  /* Remove underline animation on mobile */
  .nav-links a::after {
    display: none;
  }

  /* Mobile hover state */
  .nav-links a:hover {
    background: var(--bg-secondary);
  }

  /* Mobile active page */
  .nav-links a[aria-current="page"] {
    background: rgba(27, 77, 62, 0.08);
    font-weight: var(--font-weight-semibold);
    border-left: 3px solid var(--brand-primary);
    padding-left: calc(var(--space-md) - 3px);
  }
}

/* ============================================
   TABLET NAVIGATION (768px - 1023px)
   ============================================ */

@media (min-width: 768px) and (max-width: 1023px) {
  .nav-links {
    gap: var(--space-xs);
  }

  .nav-links a {
    padding: 0 var(--space-sm);
    font-size: var(--font-size-sm);
  }
}

/* ============================================
   DESKTOP NAVIGATION (1024px+)
   ============================================ */

@media (min-width: 1024px) {
  nav[role="navigation"] {
    padding: 0 var(--space-xl);
  }

  .nav-links {
    gap: var(--space-sm);
  }

  .nav-links a {
    padding: 0 var(--space-lg);
  }
}

/* ============================================
   STICKY HEADER BEHAVIOR (Optional Enhancement)
   ============================================ */

/* Add .header-scrolled class via JavaScript for scroll effects */
header[role="banner"].header-scrolled {
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(16px);
}

/* ============================================
   ACCESSIBILITY
   ============================================ */

/* Ensure keyboard focus is visible */
.nav-links a:focus-visible,
.nav-toggle:focus-visible,
.logo:focus-visible {
  outline: var(--focus-ring-width) var(--focus-ring-style) var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  .nav-links a::after,
  .logo,
  .nav-toggle {
    transition: none;
  }
}

/* ============================================
   PRINT
   ============================================ */

@media print {
  header[role="banner"],
  nav[role="navigation"],
  .nav-toggle {
    display: none;
  }
}