/* Header Base Styles */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--clr-bg-body);
  border-bottom: 1px solid var(--clr-border);
  transition: box-shadow var(--transition-base);
}

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

/* Logo */
.brand-logo {
  font-family: var(--font-serif);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--clr-primary);
  letter-spacing: -0.02em;
  z-index: 1002;
}

.logo-accent {
  font-weight: 400;
  color: var(--clr-text-muted);
}

/* Desktop Navigation */
.desktop-nav {
  display: none;
}

@media (min-width: 1024px) {
  .desktop-nav {
    display: block;
  }
  
  .nav-list {
    display: flex;
    gap: var(--space-6);
    list-style: none;
  }

  .nav-link {
    font-family: var(--font-sans);
    font-size: var(--fs-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--clr-text-main);
    font-weight: 500;
    padding: var(--space-2) 0;
    position: relative;
  }

  .nav-link::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 1px;
    background-color: var(--clr-primary);
    transition: width var(--transition-base);
  }

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

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

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

.action-btn {
  background: none;
  border: none;
  color: var(--clr-primary);
  font-size: var(--fs-lg);
  cursor: pointer;
  transition: color var(--transition-fast);
  padding: var(--space-1);
}

.action-btn:hover {
  color: var(--clr-primary-hover);
}

.mobile-toggle {
  display: block;
  z-index: 1002;
}

@media (min-width: 1024px) {
  .mobile-toggle {
    display: none;
  }
}

/* Mobile Menu */
.mobile-menu-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(15, 23, 42, 0.4);
  backdrop-filter: blur(2px);
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.mobile-menu-overlay.is-active {
  opacity: 1;
  visibility: visible;
}

.mobile-menu {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  max-width: 320px;
  background-color: var(--clr-bg-body);
  z-index: 1002;
  padding: var(--space-6) var(--space-6);
  transform: translateX(100%);
  transition: transform var(--transition-base);
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
}

.mobile-menu.is-open {
  transform: translateX(0);
}

.mobile-menu-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-8);
}

.mobile-brand {
  font-family: var(--font-serif);
  font-size: var(--fs-xl);
  color: var(--clr-primary);
  font-weight: 600;
}

.close-menu-btn {
  background: none;
  border: none;
  font-size: var(--fs-xl);
  color: var(--clr-text-main);
  cursor: pointer;
}

.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.mobile-nav-link {
  display: block;
  font-family: var(--font-serif);
  font-size: var(--fs-xl);
  color: var(--clr-primary);
  text-decoration: none;
  border-bottom: 1px solid var(--clr-border);
  padding-bottom: var(--space-2);
  transition: color var(--transition-fast);
}

.mobile-nav-link:hover {
  color: var(--clr-secondary);
  padding-left: var(--space-2);
}