/* =========================================================
   COMPONENT: Header
   ========================================================= */

.app-header {
  gap: var(--space-md);
}

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  font-size: var(--font-size-lg);
  color: var(--text-primary);
  letter-spacing: -0.3px;
}
.header-brand .logo-icon {
  width: 24px;
  height: 24px;
  background: var(--accent-blue);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-sm);
  font-weight: 800;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  flex: 1;
}

.nav-item {
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}
.nav-item:hover {
  color: var(--text-primary);
  background: var(--bg-hover);
}
.nav-item.is-active {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}
.nav-item.is-active::after {
  content: '';
  position: absolute;
  bottom: -13px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--accent-blue);
  border-radius: 1px;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.header-search {
  position: relative;
  width: 240px;
}
.header-search input {
  width: 100%;
  padding: var(--space-xs) var(--space-sm) var(--space-xs) 28px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: var(--font-size-sm);
  font-family: var(--font-mono);
}
.header-search input:focus {
  outline: none;
  border-color: var(--border-focus);
}
.header-search .search-icon {
  position: absolute;
  left: 8px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.header-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--accent-purple);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-xs);
  font-weight: 600;
  cursor: pointer;
}

/* Mobile nav toggle — hidden on desktop, shown under the breakpoint below */
.nav-toggle {
  display: none;
}

/* =========================================================
   RESPONSIVE: collapse the horizontal nav into a dropdown,
   hide the search bar (desktop-only for this pass)
   ========================================================= */
@media (max-width: 900px) {
  .header-search {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .header-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: var(--space-sm);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    z-index: 120;
  }

  .header-nav.is-mobile-open {
    display: flex;
  }

  .nav-item {
    padding: var(--space-md);
  }
  .nav-item.is-active::after {
    display: none;
  }
  .nav-item.is-active {
    background: var(--bg-hover);
    border-left: 3px solid var(--accent-blue);
  }
}