/* ========== Navigation - Unikode Design System ========== */
/* Source of truth: index.html */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--space-4) var(--space-6);
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  border-bottom: 1px solid var(--glass-border-top);
  transition: all var(--duration-medium-2) var(--easing-standard);
}

.nav.scrolled {
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(32px) saturate(1.4);
  -webkit-backdrop-filter: blur(32px) saturate(1.4);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.nav-inner {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
  transition: opacity var(--duration-short-4) var(--easing-standard);
}

.nav-logo:hover {
  opacity: 0.8;
}

.nav-logo img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: var(--radius-element);
  transition: filter var(--duration-short-4) var(--easing-standard);
}

/* Dark mode: brighten logo slightly for better visibility */
.nav-logo img {
  filter: brightness(1.1);
}

/* Light mode: invert logo for visibility on light background */
[data-theme="light"] .nav-logo img {
  filter: invert(1) brightness(0.2);
}

.nav-logo-text {
  font-family: var(--font-sans);
  font-size: var(--text-title-md);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  list-style: none;
}

.nav-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-body-sm);
  font-weight: 500;
  transition: color var(--duration-short-4) var(--easing-standard);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-text);
  transition: width var(--duration-medium-1) var(--easing-standard);
}

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

.nav-links a:hover::after {
  width: 100%;
}

.nav-links a.active,
.nav-links a[aria-current="page"] {
  color: var(--color-text);
}

.nav-links a.active::after,
.nav-links a[aria-current="page"]::after {
  width: 100%;
}

.nav-cta {
  padding: var(--space-2) var(--space-4);
  background: var(--color-text);
  color: var(--color-bg);
  border-radius: var(--radius-full);
  font-size: var(--text-label-md);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--duration-short-4) var(--easing-standard);
}

.nav-cta:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 20px rgba(255, 255, 255, 0.15);
}

/* ========== Light Theme Navigation ========== */
[data-theme="light"] .nav {
  background: rgba(255, 255, 255, 0.6);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

[data-theme="light"] .nav.scrolled {
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(32px) saturate(1.4);
  -webkit-backdrop-filter: blur(32px) saturate(1.4);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .nav-cta {
  background: var(--color-text);
  color: #ffffff;
}

[data-theme="light"] .nav-cta:hover {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

/* Nav Actions Container */
.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

/* ========== Hamburger Menu Button ========== */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 10px;
  z-index: 1001;
}

/* ========== Responsive Navigation ========== */
@media (max-width: 768px) {
  .nav {
    padding: var(--space-3) var(--space-4);
  }

  .nav-inner {
    gap: var(--space-2);
  }

  .nav-links {
    display: none;
  }

  .nav-logo img {
    width: 36px;
    height: 36px;
  }

  .nav-logo-text {
    font-size: var(--text-title-sm);
  }

  /* Position theme toggle and hamburger together on the right */
  .nav-actions {
    gap: var(--space-2);
    order: 2;
  }

  .theme-toggle {
    width: 40px;
    height: 40px;
  }

  .nav-hamburger {
    display: flex;
    order: 3;
  }
}

.nav-hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--duration-medium-1) var(--easing-standard);
}

.nav-hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-hamburger.active span:nth-child(2) {
  opacity: 0;
}

.nav-hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ========== Mobile Menu ========== */
.mobile-menu {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  z-index: 999;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: var(--space-6);
  opacity: 0;
  visibility: hidden;
  transition: all var(--duration-medium-2) var(--easing-standard);
}

.mobile-menu.active,
.mobile-menu.open {
  opacity: 1;
  visibility: visible;
}

.mobile-menu-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
}

.mobile-menu-links a {
  color: var(--color-text);
  text-decoration: none;
  font-size: var(--text-title-md);
  font-weight: 500;
  transition: color var(--duration-short-4) var(--easing-standard);
}

.mobile-menu-links a:hover {
  color: var(--color-text-secondary);
}

.mobile-theme-toggle {
  margin-top: var(--space-4);
}

/* Light theme mobile menu */
[data-theme="light"] .mobile-menu {
  background: var(--color-bg);
}