/* ============================================================================
   Sidebar Navigation Styles
   Modern sidebar layout with collapse/expand functionality
   ============================================================================ */

/* CSS Variables */
:root {
    --sidebar-width: 256px;
    --sidebar-collapsed-width: 64px;
    --sidebar-bg: #1E293B;
    --sidebar-hover: #334155;
    --sidebar-active: #3B82F6;
    --sidebar-text: #CBD5E1;
    --sidebar-text-muted: #94A3B8;
    --topbar-height: 60px;
    --transition-speed: 300ms;
}

/* ============================================================================
   Sidebar Container
   ============================================================================ */

.sidebar-container {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    color: var(--sidebar-text);
    display: flex;
    flex-direction: column;
    transition: width var(--transition-speed) ease;
    z-index: 40;
    overflow: hidden;
}

.sidebar-container.collapsed {
    width: var(--sidebar-collapsed-width);
}

/* ============================================================================
   Sidebar Header (Logo)
   ============================================================================ */

.sidebar-header {
    padding: 1.5rem 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    flex-shrink: 0;
}

.sidebar-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.sidebar-brand h1 {
    color: white;
    font-size: 1.125rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.sidebar-brand p {
    color: var(--sidebar-text-muted);
    font-size: 0.75rem;
    margin-top: 0.125rem;
}

/* ============================================================================
   Navigation
   ============================================================================ */

.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 1rem 0;
}

/* Custom scrollbar */
.sidebar-nav::-webkit-scrollbar {
    width: 4px;
}

.sidebar-nav::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
}

.sidebar-nav::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 2px;
}

.sidebar-nav::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* ============================================================================
   Navigation Sections
   ============================================================================ */

.nav-section {
    margin-bottom: 1.5rem;
}

.nav-section-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--sidebar-text-muted);
    margin-bottom: 0.25rem;
}

.nav-section-divider {
    height: 1px;
    background: rgba(255, 255, 255, 0.1);
    margin: 1rem 0.5rem;
}

/* ============================================================================
   Navigation Items
   ============================================================================ */

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--sidebar-text);
    text-decoration: none;
    transition: all 150ms ease;
    cursor: pointer;
    position: relative;
    white-space: nowrap;
}

.nav-item i {
    width: 20px;
    font-size: 1.125rem;
    flex-shrink: 0;
    text-align: center;
}

.nav-item span {
    font-size: 0.875rem;
    font-weight: 500;
}

/* Hover state */
.nav-item:hover {
    background-color: var(--sidebar-hover);
    color: white;
}

/* Active state */
.nav-item.active {
    background-color: var(--sidebar-active);
    color: white;
    font-weight: 600;
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background-color: white;
}

/* Collapsed state - center icons */
.sidebar-container.collapsed .nav-item {
    justify-content: center;
    padding: 0.75rem 0;
}

.sidebar-container.collapsed .nav-item i {
    margin: 0;
}

/* ============================================================================
   Sidebar Footer
   ============================================================================ */

.sidebar-footer {
    padding: 0.5rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    flex-shrink: 0;
}

.sidebar-version {
    padding: 1rem;
    text-align: center;
}

/* ============================================================================
   Collapse Toggle Button
   ============================================================================ */

.sidebar-toggle {
    position: fixed;
    left: calc(var(--sidebar-width) - 12px); /* Position at sidebar edge */
    top: 80px;
    width: 24px;
    height: 24px;
    background-color: var(--sidebar-bg);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--sidebar-text);
    cursor: pointer;
    transition: all 200ms ease;
    z-index: 50;
}

/* Move button when sidebar collapses */
body.sidebar-collapsed .sidebar-toggle,
.sidebar-container.collapsed ~ .sidebar-toggle {
    left: calc(var(--sidebar-collapsed-width) - 12px);
}

.sidebar-toggle:hover {
    background-color: var(--sidebar-active);
    color: white;
    border-color: var(--sidebar-active);
    transform: scale(1.1);
}

.sidebar-toggle i {
    font-size: 0.75rem;
    transition: transform var(--transition-speed) ease;
}

.sidebar-toggle.collapsed i {
    transform: rotate(180deg);
}

/* ============================================================================
   Mobile Overlay
   ============================================================================ */

.sidebar-overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 30;
    display: none;
}

/* ============================================================================
   Responsive Behavior
   ============================================================================ */

/* Desktop (default) */
@media (min-width: 1024px) {
    .sidebar-container {
        display: flex;
    }

    .sidebar-overlay {
        display: none !important;
    }
}

/* Tablet */
@media (max-width: 1023px) and (min-width: 768px) {
    .sidebar-container {
        width: var(--sidebar-collapsed-width);
    }

    .sidebar-container:hover {
        width: var(--sidebar-width);
    }

    /* Hide text by default on tablet */
    .sidebar-container .nav-item span,
    .sidebar-container .nav-section-header,
    .sidebar-container .sidebar-brand,
    .sidebar-container .sidebar-version {
        display: none;
    }

    /* Show text on hover */
    .sidebar-container:hover .nav-item span,
    .sidebar-container:hover .nav-section-header,
    .sidebar-container:hover .sidebar-brand,
    .sidebar-container:hover .sidebar-version {
        display: block;
    }

    .sidebar-container .nav-item {
        justify-content: center;
    }

    .sidebar-container:hover .nav-item {
        justify-content: flex-start;
    }
}

/* Mobile */
@media (max-width: 767px) {
    .sidebar-container {
        transform: translateX(-100%);
        transition: transform var(--transition-speed) ease;
    }

    .sidebar-container.mobile-open {
        transform: translateX(0);
    }

    .sidebar-overlay.mobile-open {
        display: block !important;
    }

    .sidebar-toggle {
        display: none;
    }
}

/* ============================================================================
   Layout Adjustments for Sidebar
   ============================================================================ */

/* Main content area should be offset by sidebar width */
body.has-sidebar {
    padding-left: var(--sidebar-width);
    transition: padding-left var(--transition-speed) ease;
}

body.has-sidebar.sidebar-collapsed {
    padding-left: var(--sidebar-collapsed-width);
}

/* Mobile: no padding */
@media (max-width: 767px) {
    body.has-sidebar {
        padding-left: 0;
    }
}

/* Tablet: collapsed sidebar padding */
@media (max-width: 1023px) and (min-width: 768px) {
    body.has-sidebar {
        padding-left: var(--sidebar-collapsed-width);
    }
}

/* No sidebar (login page) - center content */
body:not(.has-sidebar) {
    padding-left: 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #EFF6FF; /* Pale blue (blue-50) */
}

body:not(.has-sidebar) main {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* ============================================================================
   Animation Classes
   ============================================================================ */

.fade-in {
    animation: fadeIn var(--transition-speed) ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.slide-in-left {
    animation: slideInLeft var(--transition-speed) ease;
}

@keyframes slideInLeft {
    from {
        transform: translateX(-20px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* ============================================================================
   Accessibility
   ============================================================================ */

/* Focus visible styles */
.nav-item:focus-visible {
    outline: 2px solid var(--sidebar-active);
    outline-offset: -2px;
}

.sidebar-toggle:focus-visible {
    outline: 2px solid var(--sidebar-active);
    outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .sidebar-container,
    .sidebar-toggle i,
    .nav-item,
    body.has-sidebar {
        transition: none;
    }
}