.app-header {
    position: fixed;
    top: 0;
    left: var(--sidebar-width);
    right: 0;
    height: var(--header-height);
    background: rgba(247, 246, 243, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--content-padding);
    z-index: var(--z-header);
    transition: left var(--transition-base);
    gap: var(--space-4);
}

.app-header.sidebar-collapsed { left: var(--sidebar-collapsed); }

.page-breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

@media (max-width: 768px) {
    .page-breadcrumb {
        display: none;
    }
}

.page-breadcrumb a:hover { color: var(--color-text-primary); }