/* base.css - reset, body, shell layout (sidebar/topbar/page-content), accessibility primitives */

body {
    background-color: var(--content-bg);
    color: var(--color-text-primary);
    font-family: var(--font-sans);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Accessibility: visible keyboard focus everywhere, skip-link */
:focus-visible {
    outline: 3px solid var(--color-focus-ring);
    outline-offset: 2px;
}

.skip-link {
    position: absolute;
    top: -100px;
    left: var(--space-4);
    z-index: var(--z-toast);
    background: var(--primary-blue);
    color: var(--color-text-inverse);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-md);
    font-weight: var(--font-weight-semibold);
    transition: top var(--transition-base);
}

.skip-link:focus {
    top: var(--space-4);
}

/* Shell layout */
#wrapper {
    display: flex;
    width: 100%;
    align-items: stretch;
}

#sidebar-wrapper {
    min-height: 100vh;
    width: 260px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    transition: margin-left var(--transition-base);
    z-index: var(--z-sticky);
}

.sidebar-heading {
    padding: var(--space-6) var(--space-6) var(--space-4);
    font-size: var(--text-md);
    color: var(--color-text-primary);
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.01em;
    display: flex;
    align-items: center;
}

#sidebar-wrapper .list-group-item {
    background: transparent;
    border: none;
    color: var(--sidebar-text);
    padding: var(--space-2) var(--space-3);
    font-size: 0.8125rem;
    font-weight: var(--font-weight-medium);
    transition: background-color var(--transition-base), color var(--transition-base);
}

#sidebar-wrapper .list-group-item:hover,
#sidebar-wrapper .list-group-item:focus-visible {
    background-color: var(--sidebar-hover);
    color: var(--color-text-primary);
}

#sidebar-wrapper .list-group-item.active {
    background-color: var(--color-info-bg);
    color: var(--primary-blue);
    border-left: none;
    border: 1px solid var(--color-border-strong);
}

#sidebar-wrapper .list-group-item i {
    width: 16px;
    margin-right: 10px;
    font-size: 0.9rem;
    opacity: 0.85;
}

#sidebar-wrapper .list-group-item.active i {
    opacity: 1;
}

#page-content-wrapper {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
}

/* Page Header */
.page-header {
    background: var(--color-surface);
    padding: var(--space-6) var(--space-8);
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--space-8);
}

.page-title {
    font-weight: var(--font-weight-bold);
    color: var(--color-text-primary);
    margin-bottom: var(--space-1);
    letter-spacing: -0.01em;
}

/* Animations */
.fade-in {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
    .fade-in { animation: none; }
    * { transition-duration: 0.01ms !important; }
}

/* Mobile Responsive */
@media (max-width: 768px) {
    #sidebar-wrapper {
        margin-left: -260px;
        position: fixed;
    }
    body.sb-sidenav-toggled #sidebar-wrapper {
        margin-left: 0;
    }
    .page-header {
        padding: var(--space-4) var(--space-5);
    }
}