:root {
    /* Color Palette - Minimalist & Premium */
    --bg-body: #f9fafb;
    --bg-card: #ffffff;
    --bg-sidebar: #ffffff;

    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;

    --primary-color: #0f172a;
    /* Deep Slate */
    --primary-hover: #1e293b;
    --accent-color: #3b82f6;
    /* Subtle Blue for active states/links */

    --border-color: #e5e7eb;
    --border-focus: #0f172a;

    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

    /* Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--accent-color);
}

/* Layout */
.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 260px;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: var(--spacing-lg);
    position: fixed;
    height: 100vh;
    top: 0;
    left: 0;
    z-index: 50;
}

.main-content {
    flex: 1;
    margin-left: 260px;
    /* Match sidebar width */
    padding: var(--spacing-xl);
    max-width: 100%;
}

/* Sidebar Components */
.brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.2s;
}

.nav-item:hover {
    background-color: var(--bg-body);
    color: var(--text-primary);
}

.nav-item.active {
    background-color: var(--bg-body);
    color: var(--primary-color);
    font-weight: 600;
}

.nav-icon {
    width: 20px;
    height: 20px;
    stroke-width: 2;
}

.user-profile {
    margin-top: auto;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.logout-btn {
    color: var(--text-muted);
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
}

.logout-btn:hover {
    color: var(--error-color);
    background-color: #fef2f2;
}

/* UI Components */
.page-header {
    margin-bottom: var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.page-title {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: -0.025em;
}

.page-subtitle {
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.card {
    background-color: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
}

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

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

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

.btn-secondary:hover {
    background-color: var(--bg-body);
    border-color: #d1d5db;
}

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

.btn-danger:hover {
    background-color: #fef2f2;
    border-color: #fecaca;
}

.btn-sm {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.form-control {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background-color: white;
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(15, 23, 42, 0.1);
}

/* Tables */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.table th {
    background-color: var(--bg-body);
    color: var(--text-secondary);
    font-weight: 600;
    text-align: left;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
}

.table td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

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

.table tr:hover td {
    background-color: var(--bg-body);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.125rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 500;
}

.badge-success {
    background-color: #d1fae5;
    color: #065f46;
}

.badge-error {
    background-color: #fee2e2;
    color: #991b1b;
}

.badge-neutral {
    background-color: #f3f4f6;
    color: #374151;
}

/* Utilities */
.flex {
    display: flex;
}

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

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

.gap-2 {
    gap: 0.5rem;
}

.gap-4 {
    gap: 1rem;
}

.mt-4 {
    margin-top: 1rem;
}

.mb-4 {
    margin-bottom: 1rem;
}

.text-sm {
    font-size: 0.875rem;
}

.text-muted {
    color: var(--text-muted);
}

.font-mono {
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    pointer-events: none;
    /* Allow clicking through container */
}

.toast {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: 300px;
    max-width: 400px;
    pointer-events: auto;
    /* Re-enable pointer events for toasts */
    animation: slideIn 0.3s ease-out forwards;
    transform-origin: top right;
}

.toast.success {
    border-left: 4px solid var(--success-color);
}

.toast.error {
    border-left: 4px solid var(--error-color);
}

.toast.info {
    border-left: 4px solid var(--accent-color);
}

.toast-icon {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
}

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

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

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

.toast-content {
    flex: 1;
    font-size: 0.875rem;
    color: var(--text-primary);
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
        transform: translateX(0);
    }

    to {
        opacity: 0;
        transform: translateX(100%);
    }
}

/* Mobile Responsive */
.mobile-nav-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 60;
    background-color: white;
    border: 1px solid var(--border-color);
    padding: 0.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    color: var(--text-primary);
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 40;
    opacity: 0;
    transition: opacity 0.3s;
}

.sidebar-overlay.show {
    display: block;
    opacity: 1;
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }

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

    .main-content {
        margin-left: 0;
        padding: var(--spacing-md);
        padding-top: 4rem;
        /* Space for the toggle button */
    }

    .mobile-nav-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }
}

/* Login Page Specific */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background-color: var(--bg-body);
}

.login-card {
    width: 100%;
    max-width: 400px;
    padding: 2.5rem;
}

/* Flash Messages */
.flash-messages {
    margin-bottom: var(--spacing-lg);
}

.alert {
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.alert-success {
    background-color: #ecfdf5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background-color: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}