:root {
    /* Premium Color Palette */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;
    
    /* Neutral Colors */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Traffic Light Colors */
    --red-500: #ef4444;
    --red-600: #dc2626;
    --yellow-500: #f59e0b;
    --yellow-600: #d97706;
    --green-500: #10b981;
    --green-600: #059669;
    
    /* Background & Text */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    /* 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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Loading Spinner */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    gap: var(--spacing-lg);
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--primary-500);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

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

/* Sidebar */
.sidebar {
    width: 260px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--bg-tertiary);
    overflow-y: auto;
    transition: transform var(--transition-base);
}

.sidebar-header {
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--bg-tertiary);
}

.sidebar-logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-400), var(--primary-600));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.sidebar-nav {
    padding: var(--spacing-lg);
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    cursor: pointer;
    margin-bottom: var(--spacing-sm);
}

.nav-item:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    transform: translateX(4px);
}

.nav-item.active {
    background: var(--primary-600);
    color: white;
}

.nav-item-icon {
    font-size: 1.25rem;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* Header */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--bg-tertiary);
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
}

.company-selector {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.company-selector:hover {
    background: var(--bg-primary);
    transform: scale(1.02);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-500), var(--primary-700));
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: white;
}

/* Content Area */
.content {
    flex: 1;
    padding: var(--spacing-xl);
    overflow-y: auto;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Cards */
.card {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
}

/* Grid System */
.grid {
    display: grid;
    gap: var(--spacing-lg);
}

.grid-cols-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-cols-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-cols-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-lg);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-500), var(--primary-700));
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

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

.btn-danger {
    background: linear-gradient(135deg, var(--red-500), var(--red-600));
    color: white;
}

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

.form-label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--text-secondary);
}

.form-input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-500);
    background: var(--bg-primary);
}

/* Traffic Light Indicators */
.indicator {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-lg);
    font-weight: 600;
}

.indicator-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    box-shadow: 0 0 8px currentColor;
}

.indicator-green {
    background: rgba(16, 185, 129, 0.1);
    color: var(--green-500);
}

.indicator-yellow {
    background: rgba(245, 158, 11, 0.1);
    color: var(--yellow-500);
}

.indicator-red {
    background: rgba(239, 68, 68, 0.1);
    color: var(--red-500);
}

/* Table */
.table {
    width: 100%;
    border-collapse: collapse;
}

.table th {
    text-align: left;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    font-weight: 600;
    color: var(--text-secondary);
}

.table td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--bg-tertiary);
}

.table tr:hover {
    background: var(--bg-tertiary);
}

/* Auth Pages */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary));
}

.auth-card {
    width: 100%;
    max-width: 450px;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-xl);
}

.auth-title {
    font-size: 1.75rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
        z-index: 1000;
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .grid-cols-2,
    .grid-cols-3,
    .grid-cols-4 {
        grid-template-columns: 1fr;
    }
}

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

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

/* Utilities */
.hidden {
    display: none !important;
}

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

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

.mt-4 {
    margin-top: var(--spacing-lg);
}

.mb-4 {
    margin-bottom: var(--spacing-lg);
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 1;
    transition: opacity var(--transition-base);
}

.modal-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 500px;
    box-shadow: var(--shadow-2xl);
    transform: scale(1);
    transition: transform var(--transition-base);
    max-height: 90vh;
    display: flex;
    flex-direction: column;
}

.modal-overlay.hidden .modal {
    transform: scale(0.95);
}

.modal-header {
    padding: var(--spacing-lg) var(--spacing-xl);
    border-bottom: 1px solid var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    line-height: 1;
    transition: color var(--transition-fast);
}

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

.modal-body {
    padding: var(--spacing-xl);
    overflow-y: auto;
}

.modal-footer {
    padding: var(--spacing-lg) var(--spacing-xl);
    border-top: 1px solid var(--bg-tertiary);
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-md);
}

/* Select Input Style */
.form-select {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
    appearance: none;
    background-image: url('data:image/svg+xml,%3Csvg xmlns=\'http://www.w3.org/2000/svg\' fill=\'none\' viewBox=\'0 0 24 24\' stroke=\'%239ca3af\'%3E%3Cpath stroke-linecap=\'round\' stroke-linejoin=\'round\' stroke-width=\'2\' d=\'M19 9l-7 7-7-7\'%3E%3C/path%3E%3C/svg%3E');
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1.5em;
}

.form-select:focus {
    outline: none;
    border-color: var(--primary-500);
    background-color: var(--bg-primary);
}