.app-header {
  grid-area: header;
  background: var(--header-bg);
  border-bottom: 1px solid var(--header-border);
  display: flex;
  align-items: center;
  padding: 0 var(--space-xl);
  gap: var(--space-md);
  height: var(--header-height);
  position: sticky;
  top: 0;
  z-index: 90;
  box-shadow: var(--shadow-sm);
}

/* ── Breadcrumb ───────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--font-base);
  color: var(--color-text-secondary);
  flex: 1;
}

.breadcrumb__sep { color: var(--color-border); }
.breadcrumb__current { color: var(--color-text-primary); font-weight: 500; }

/* ── Search bar ───────────────────────────────────────── */
.header-search {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: 6px 14px;
  width: 280px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.header-search:focus-within {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.header-search input {
  border: none;
  background: none;
  outline: none;
  font-size: var(--font-base);
  color: var(--color-text-primary);
  width: 100%;
}

.header-search input::placeholder { color: var(--color-text-muted); }

.header-search__icon { color: var(--color-text-muted); font-size: 16px; }

/* ── Header actions ───────────────────────────────────── */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-left: auto;
}

.header-btn {
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--color-text-secondary);
  font-size: 18px;
  transition: background var(--transition), color var(--transition);
  position: relative;
}

.header-btn:hover {
  background: var(--color-bg);
  color: var(--color-text-primary);
}

/* Notification dot */
.header-btn.has-notification::after {
  content: '';
  position: absolute;
  top: 6px;
  right: 6px;
  width: 8px;
  height: 8px;
  background: var(--color-danger);
  border-radius: 50%;
  border: 2px solid #fff;
}

/* ── User avatar ──────────────────────────────────────── */
.user-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-sm);
  font-weight: 700;
  cursor: pointer;
  flex-shrink: 0;
  border: 2px solid transparent;
  transition: border-color var(--transition);
}
.user-avatar:hover { border-color: var(--color-primary); }

/* ── Environment badge ────────────────────────────────── */
.env-badge {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  letter-spacing: .5px;
}
.env-badge.development { background: #fff3cd; color: #856404; }
.env-badge.production  { background: #d4edda; color: #155724; }