/* Header CSS - 2025 Design System */
/* Header branding, theme toggle, and mobile menu styles */

/* ================================
   HEADER 2025 STYLES
   ================================ */

.header-2025 {
  position: sticky;
  top: 0;
  z-index: var(--z-index-sticky, 1020);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-smooth);
}

/* Top Header Section */
.header-top {
  background: var(--surface-primary);
  border-bottom: 1px solid var(--border-primary);
}

/* Header Content */
.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-4) 0;
  min-height: 80px;
}

/* Branding */
.header-brand {
  flex-shrink: 0;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-fast);
  padding: var(--spacing-2);
  border-radius: var(--radius-md);
}

.brand-link:hover {
  transform: translateY(-1px);
  background: var(--primary-50);
}

.brand-link:focus-visible {
  outline: 2px solid var(--primary-600);
  outline-offset: 2px;
}

.brand-logo {
  height: 40px;
  width: auto;
  object-fit: contain;
  transition: all var(--transition-fast);
}

.brand-link:hover .brand-logo {
  transform: scale(1.05);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.brand-title {
  font-family: var(--font-display);
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
  margin: 0;
  line-height: 1.1;
  background: linear-gradient(135deg, var(--primary-700), var(--accent-600));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.brand-subtitle {
  font-family: var(--font-primary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wide);
  margin-top: -2px;
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--border-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.theme-toggle:hover {
  background: var(--primary-50);
  border-color: var(--primary-300);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--primary-600);
  outline-offset: 2px;
}

.sun-icon,
.moon-icon {
  position: absolute;
  transition: all var(--transition-fast);
}

[data-theme="light"] .sun-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="light"] .moon-icon {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

[data-theme="dark"] .sun-icon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

[data-theme="dark"] .moon-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--spacing-2);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.mobile-menu-toggle:hover {
  background: var(--primary-50);
}

.mobile-menu-toggle:focus-visible {
  outline: 2px solid var(--primary-600);
  outline-offset: 2px;
}

.hamburger-line {
  width: 20px;
  height: 2px;
  background: var(--text-primary);
  margin: 2px 0;
  transition: all var(--transition-fast);
  border-radius: 1px;
}

/* Animated hamburger */
.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-content {
    padding: var(--spacing-3) 0;
    min-height: 70px;
  }
  
  .brand-title {
    font-size: var(--font-size-xl);
  }
  
  .brand-logo {
    height: 32px;
  }
  
  .mobile-menu-toggle {
    display: flex;
  }
}

@media (max-width: 480px) {
  .brand-text {
    display: none;
  }
  
  .header-actions {
    gap: var(--spacing-2);
  }
}

/* Dark Mode Support */
[data-theme="dark"] .header-top {
  background: rgba(15, 15, 15, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

[data-theme="dark"] .brand-title {
  background: linear-gradient(135deg, var(--primary-400), var(--accent-400));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="dark"] .theme-toggle:hover {
  background: var(--primary-900);
  border-color: var(--primary-600);
}

[data-theme="dark"] .mobile-menu-toggle:hover {
  background: var(--primary-900);
}

[data-theme="dark"] .brand-link:hover {
  background: var(--primary-900);
  box-shadow: 0 0 20px rgba(34, 214, 208, 0.1);
}

/* Animation for smooth header entrance */
@keyframes headerSlideIn {
  from {
    transform: translateY(-100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.header-2025 {
  animation: headerSlideIn var(--transition-smooth);
}

/* Accessibility Enhancements */
@media (prefers-reduced-motion: reduce) {
  .mobile-menu-toggle,
  .theme-toggle,
  .brand-link,
  .header-2025 {
    transition: none;
    animation: none;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  .theme-toggle {
    border-width: 2px;
  }
  
  .brand-link {
    border: 1px solid transparent;
  }
  
  .brand-link:hover,
  .brand-link:focus-visible {
    border-color: var(--text-primary);
  }
}