/* ============================================
   header.css — Header & Navigation
   ============================================ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* Logo / Name */
.header-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  flex-shrink: 0;
}

.header-brand__name {
  font-family: var(--font-heading);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text-primary);
  line-height: 1.2;
}

.header-brand__role {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  font-weight: 400;
  display: block;
}

/* Main Nav */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-desktop__list {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-desktop__link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-desktop__link:hover,
.nav-desktop__link.active {
  color: var(--color-accent);
}

.nav-desktop__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-base);
}

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

/* Mobile burger */
.burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.burger__line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.burger.open .burger__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.burger.open .burger__line:nth-child(2) {
  opacity: 0;
}

.burger.open .burger__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile overlay */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 999;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.nav-mobile.open {
  display: flex;
  opacity: 1;
  visibility: visible;
}

.nav-mobile__link {
  font-size: var(--font-size-xl);
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--color-text-primary);
  text-decoration: none;
  padding: var(--space-sm) var(--space-md);
  transition: color var(--transition-fast);
}

.nav-mobile__link:hover {
  color: var(--color-accent);
}

/* Responsive */
@media (max-width: 768px) {
  .nav-desktop__list {
    display: none;
  }

  .burger {
    display: flex;
  }

  .header-brand__role {
    display: none;
  }
}