:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary: #64748b;
    --accent: #f59e0b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --bg-sidebar: #1e293b;
    --bg-topbar: #ffffff;
    
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --text-sidebar: #e2e8f0;
    
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    
    --sidebar-width: 260px;
    --sidebar-collapsed: 70px;
    --topbar-height: 70px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

/* Dark Mode Variables */
body.dark-mode {
    --bg-main: #0f172a;
    --bg-card: #1e293b;
    --bg-sidebar: #0f172a;
    --bg-topbar: #1e293b;
    
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-light: #64748b;
    
    --border-color: #334155;
    --border-light: #1e293b;
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Sidebar Styles */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    color: var(--text-sidebar);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-base), width var(--transition-base);
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

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

.sidebar.collapsed .logo-text,
.sidebar.collapsed .nav-item span,
.sidebar.collapsed .user-details,
.sidebar.collapsed .btn-logout span {
    opacity: 0;
    visibility: hidden;
}

.sidebar-header {
    padding: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
}

.logo i {
    font-size: 1.75rem;
    color: var(--primary-light);
}

.logo-text {
    transition: opacity var(--transition-base), visibility var(--transition-base);
}

.sidebar-toggle {
    background: none;
    border: none;
    color: var(--text-sidebar);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

.sidebar-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

.sidebar-nav {
    flex: 1;
    padding: 1.5rem 0;
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1.5rem;
    color: var(--text-sidebar);
    text-decoration: none;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-item i {
    font-size: 1.25rem;
    min-width: 1.25rem;
}

.nav-item span {
    transition: opacity var(--transition-base), visibility var(--transition-base);
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.05);
    color: #ffffff;
}

.nav-item.active {
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    color: #ffffff;
    font-weight: 600;
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: #ffffff;
}

.sidebar-footer {
    padding: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.user-avatar {
    font-size: 2.5rem;
    color: var(--primary-light);
}

.user-details {
    flex: 1;
    transition: opacity var(--transition-base), visibility var(--transition-base);
}

.user-name {
    font-weight: 600;
    font-size: 0.9rem;
}

.user-role {
    font-size: 0.75rem;
    color: var(--text-light);
}

.logout-form {
    width: 100%;
}

.btn-logout {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #fca5a5;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.9rem;
}

.btn-logout:hover {
    background: rgba(239, 68, 68, 0.2);
    border-color: rgba(239, 68, 68, 0.5);
}

.btn-logout i {
    font-size: 1.1rem;
}

/* Main Wrapper */
.main-wrapper {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: margin-left var(--transition-base);
}

body.sidebar-collapsed .main-wrapper {
    margin-left: var(--sidebar-collapsed);
}

/* Topbar */
.topbar {
    height: var(--topbar-height);
    background: var(--bg-topbar);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 2rem;
    gap: 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.menu-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-primary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
    display: none;
}

.menu-toggle:hover {
    background: var(--bg-main);
}

.topbar-title {
    flex: 1;
}

.topbar-title h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.topbar-action {
    position: relative;
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.625rem;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.topbar-action:hover {
    background: var(--bg-main);
    color: var(--text-primary);
}

.topbar-action .badge {
    position: absolute;
    top: 4px;
    right: 4px;
    background: var(--danger);
    color: white;
    font-size: 0.65rem;
    padding: 0.15rem 0.35rem;
    border-radius: 10px;
    font-weight: 600;
}

/* Content */
.content {
    flex: 1;
    padding: 2rem;
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
}

/* Footer */
.footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-fast);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card h2,
.card h3 {
    margin-top: 0;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* Grid Layout */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

/* Stats Cards */
.stats {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    padding: 0;
    margin-bottom: 2rem;
}

.stats li {
    background: var(--bg-card);
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.stats li:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.stats span {
    display: block;
    font-size: 0.875rem;
    text-transform: uppercase;
    color: var(--text-secondary);
    font-weight: 600;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.stats strong {
    display: block;
    font-size: 2.5rem;
    color: var(--primary);
    font-weight: 700;
}

/* Forms */
.form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1.25rem;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    background: var(--bg-card);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

/* Buttons */
button,
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--secondary);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    background: #475569;
}

.btn-success {
    background: var(--success);
    color: white;
}

.btn-success:hover:not(:disabled) {
    background: #059669;
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
}

.btn-warning {
    background: var(--warning);
    color: white;
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: white;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background: var(--bg-main);
}

th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-primary);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.5px;
    border-bottom: 2px solid var(--border-color);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-primary);
}

tr:last-child td {
    border-bottom: none;
}

tbody tr {
    transition: background var(--transition-fast);
}

tbody tr:hover {
    background: var(--bg-main);
}

/* Page Header */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
}

.page-header h2 {
    font-size: 1.75rem;
    color: var(--text-primary);
    margin: 0;
}

/* Filters */
.filters,
.inline-form {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

/* Lists */
.list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.875rem;
    background: var(--bg-main);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.list li:hover {
    background: var(--border-light);
    transform: translateX(4px);
}

/* Actions */
.actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.actions-row {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1.5rem;
}

/* Auth Layout */
.auth-layout {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    padding: 2rem;
}

.auth-card {
    max-width: 420px;
    width: 100%;
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.auth-card h2 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    text-align: center;
    color: var(--text-primary);
}

.auth-card p {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.auth-card button {
    width: 100%;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: calc(var(--topbar-height) + 1rem);
    right: 1rem;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    max-width: 400px;
}

.toast {
    background: var(--bg-card);
    border-left: 4px solid var(--primary);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 1rem 1.25rem;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    animation: slideIn 0.3s ease-out;
    position: relative;
    overflow: hidden;
}

.toast::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary);
    animation: progress 5s linear;
}

.toast.success {
    border-left-color: var(--success);
}

.toast.success::before {
    background: var(--success);
}

.toast.danger,
.toast.error {
    border-left-color: var(--danger);
}

.toast.danger::before,
.toast.error::before {
    background: var(--danger);
}

.toast.warning {
    border-left-color: var(--warning);
}

.toast.warning::before {
    background: var(--warning);
}

.toast.info {
    border-left-color: var(--info);
}

.toast.info::before {
    background: var(--info);
}

.toast-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.toast.success .toast-icon {
    color: var(--success);
}

.toast.danger .toast-icon,
.toast.error .toast-icon {
    color: var(--danger);
}

.toast.warning .toast-icon {
    color: var(--warning);
}

.toast.info .toast-icon {
    color: var(--info);
}

.toast-content {
    flex: 1;
}

.toast-message {
    color: var(--text-primary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.toast-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    font-size: 1.25rem;
    flex-shrink: 0;
    transition: color var(--transition-fast);
}

.toast-close:hover {
    color: var(--text-primary);
}

@keyframes slideIn {
    from {
        transform: translateX(120%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideOut {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(120%);
        opacity: 0;
    }
}

@keyframes progress {
    from {
        transform: scaleX(1);
    }
    to {
        transform: scaleX(0);
    }
}

.toast.removing {
    animation: slideOut 0.3s ease-out forwards;
}

/* Responsive Design */
@media (max-width: 1024px) {
    :root {
        --sidebar-width: 240px;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }

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

    .main-wrapper {
        margin-left: 0;
    }

    .menu-toggle {
        display: block;
    }

    .topbar {
        padding: 0 1rem;
    }

    .topbar-title h1 {
        font-size: 1.25rem;
    }

    .content {
        padding: 1.5rem;
    }

    .stats {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }

    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .toast-container {
        left: 1rem;
        right: 1rem;
        max-width: none;
    }
}

@media (max-width: 480px) {
    .topbar-title h1 {
        font-size: 1.1rem;
    }

    .stats strong {
        font-size: 2rem;
    }

    .auth-card {
        padding: 1.5rem;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

.w-full {
    width: 100%;
}

.hidden {
    display: none;
}