/*
 * Site header component — pairs with app/views/shared/_site_header.html.erb
 * Includes the desktop header, nav dropdowns, mobile drawer, theme toggle.
 */
.site-header {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  height: var(--nav-height);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-2xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2xl);
  height: 100%;
}

.logo {
  font-family: var(--font-logo);
  font-size: var(--font-size-xl);
  font-weight: 500;
  font-variant: small-caps;
  letter-spacing: 0.12em;
  color: var(--color-primary);
  white-space: nowrap;
}

.logo:hover {
  text-decoration: none;
}

@media (max-width: 480px) {
  .logo {
    font-size: var(--font-size-md);
    letter-spacing: 0.08em;
  }
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
}

.nav-links a {
  color: var(--color-text-light);
  font-size: var(--font-size-base);
  font-weight: 500;
  transition: color 0.15s;
}

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

.nav-links a:hover {
  color: var(--color-text);
  text-decoration: none;
}

.nav-links a[aria-current="page"],
.nav-links a[aria-current="true"] {
  color: var(--color-primary);
  position: relative;
}

.nav-links a[aria-current="page"]::after,
.nav-links a[aria-current="true"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -8px;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
}

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

/* ===== Nav Dropdown ===== */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  margin-top: var(--space-sm);
  padding: var(--space-sm) 0;
  list-style: none;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-float);
  min-width: 140px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.12s ease, visibility 0.12s ease;
  z-index: var(--z-dropdown);
}

/* Hover bridge — invisible area between link and menu to prevent gap-flicker */
.nav-dropdown::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  height: var(--space-sm);
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
}

.nav-dropdown-menu li a {
  display: block;
  padding: var(--space-sm) var(--space-lg);
  color: var(--color-text-light);
  font-weight: 400;
  font-size: var(--font-size-sm);
  white-space: nowrap;
}

.nav-dropdown-menu li a:hover {
  background: var(--color-surface);
  color: var(--color-text);
  text-decoration: none;
}

/* ===== Hamburger Button (visible on mobile only) ===== */
.hamburger-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: var(--tap-target-min);
  height: var(--tap-target-min);
  padding: 0;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text);
}

/* ===== Nav Overlay (mobile drawer backdrop) ===== */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--color-overlay);
  z-index: var(--z-nav-overlay);
}

.nav-overlay.active {
  display: block;
}

/* ===== Theme Toggle ===== */
.theme-toggle {
  width: 36px;
  height: 36px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: var(--radius);
  color: var(--color-text-light);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s;
}

.theme-toggle:hover {
  background: var(--color-surface);
  color: var(--color-text);
}

/* ===== Mobile Drawer ===== */
@media (max-width: 768px) {
  .hamburger-btn {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -280px;
    width: 280px;
    height: 100vh;
    height: 100dvh;
    background: var(--color-bg-card);
    border-left: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--space-2xl) var(--space-xl);
    gap: 0;
    z-index: var(--z-dropdown);
    overflow-y: auto;
    transition: right 0.3s ease;
  }

  .nav-links.nav-open {
    right: 0;
  }

  /* Flatten dropdown wrappers in mobile menu */
  .nav-dropdown {
    display: contents;
  }

  .nav-dropdown-menu {
    display: none;
  }

  .nav-links a,
  .nav-links form {
    display: flex;
    align-items: center;
    padding: var(--space-lg) 0;
    font-size: var(--font-size-md);
    border-bottom: 1px solid var(--color-border);
    min-height: var(--tap-target-min);
  }

  .nav-links a.btn,
  .nav-links .btn,
  .nav-links a.btn-secondary,
  .nav-links .btn-secondary {
    margin-top: var(--space-lg);
    text-align: center;
    justify-content: center;
    border-bottom: none;
    width: 100%;
    padding: var(--space-sm) var(--space-lg);
    font-size: var(--font-size-sm);
  }
}