/**
 * Dr. Anil Kumar's Eye Hospital - Header Component Styles
 * =======================================================
 * Desktop horizontal header + responsive mobile drawer navigation.
 */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: box-shadow var(--transition-base);
}

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
  gap: var(--space-4);
}

/* Brand Wordmark */
.site-brand {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  line-height: 1.15;
}

.site-brand:hover {
  text-decoration: none;
}

.brand-title {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-blue-wordmark);
  letter-spacing: -0.01em;
}

.brand-subtitle {
  font-family: var(--font-body);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-green-accent-light);
  margin-top: 2px;
}

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

@media (min-width: 1024px) {
  .primary-nav {
    display: flex;
    align-items: center;
    gap: var(--space-8);
  }
}

.nav-list {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--space-6);
}

.nav-item {
  display: inline-flex;
  align-items: center;
}

.nav-link {
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  color: var(--color-navy-900);
  text-decoration: none;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-1);
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-blue-600);
  text-decoration: none;
}

.nav-link.is-active {
  color: var(--color-blue-600);
  font-weight: var(--fw-semibold);
}

.nav-link.is-active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-green-accent-light);
  border-radius: var(--radius-full);
}

/* Header Action (Book Appointment) */
.header-actions {
  display: none;
}

@media (min-width: 640px) {
  .header-actions {
    display: flex;
    align-items: center;
  }
}

/* Mobile Hamburger Button */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-navy-900);
  transition: background-color var(--transition-fast);
}

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

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

.nav-toggle-icon {
  position: relative;
  width: 20px;
  height: 2px;
  background-color: currentColor;
  transition: background-color var(--transition-fast);
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: currentColor;
  transition: transform var(--transition-fast), top var(--transition-fast);
}

.nav-toggle-icon::before {
  top: -6px;
}

.nav-toggle-icon::after {
  top: 6px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
  top: 0;
  transform: rotate(-45deg);
}

/* Mobile Navigation Drawer */
.mobile-nav-drawer {
  position: fixed;
  top: 80px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transform: translateY(-100%);
  opacity: 0;
  visibility: hidden;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1),
              opacity 0.2s ease,
              visibility 0.25s;
  z-index: 999;
  border-top: 1px solid var(--color-border);
  overflow-y: auto;
}

.mobile-nav-drawer.is-open {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

@media (min-width: 1024px) {
  .mobile-nav-drawer {
    display: none !important;
  }
}

.mobile-nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  min-height: 44px;
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  color: var(--color-navy-900);
  text-decoration: none;
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--color-border-subtle);
}

.mobile-nav-link:hover,
.mobile-nav-link.is-active {
  color: var(--color-blue-600);
}

.mobile-nav-footer {
  margin-top: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

/* Accessible Skip Link */
.skip-link {
  position: absolute;
  top: -999px;
  left: var(--space-4);
  background-color: var(--color-navy-900);
  color: #FFFFFF;
  padding: var(--space-3) var(--space-5);
  font-weight: var(--fw-semibold);
  border-radius: var(--radius-md);
  z-index: 10000;
  text-decoration: none;
  box-shadow: var(--shadow-lg);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
  outline: 2px solid var(--color-green-accent-light);
  outline-offset: 2px;
}