:root {
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #6366f1;
    --secondary-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --bg-dark: #1f2937;
    
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --text-white: #ffffff;
    
    --border-color: #e5e7eb;
    --border-dark: #d1d5db;
    
    --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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    --sidebar-width: 280px;
    --header-height: 64px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-secondary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Login Page */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 2rem;
}

.login-container {
    width: 100%;
    max-width: 420px;
}

.login-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    padding: 2.5rem;
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.login-form {
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.login-footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.login-footer p {
    color: var(--text-tertiary);
    font-size: 0.85rem;
}

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

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
    color: var(--text-white);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    left: 0;
    top: 0;
    box-shadow: var(--shadow-lg);
    z-index: 100;
}

.sidebar-header {
    padding: 2rem 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-logo {
    font-size: 1.75rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.25rem;
}

.sidebar-subtitle {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.6);
}

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

.nav-item {
    display: flex;
    align-items: center;
    padding: 0.875rem 1rem;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    border-radius: var(--radius-md);
    margin-bottom: 0.5rem;
    transition: var(--transition);
    font-weight: 500;
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-white);
}

.nav-item.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-white);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.nav-icon {
    width: 20px;
    height: 20px;
    margin-right: 0.75rem;
}

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

.user-info {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    margin-right: 0.75rem;
    font-size: 1.1rem;
}

.user-details {
    flex: 1;
}

.user-name {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.125rem;
}

.user-role {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.6);
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    background: var(--bg-secondary);
}

.content-wrapper {
    padding: 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    font-family: inherit;
}

.btn-icon {
    width: 18px;
    height: 18px;
    margin-right: 0.5rem;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-white);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-white);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
}

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

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

.btn-block {
    width: 100%;
}

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

/* Alerts */
.alert {
    display: flex;
    align-items: center;
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.alert-icon {
    width: 20px;
    height: 20px;
    margin-right: 0.75rem;
    flex-shrink: 0;
}

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

.alert-success {
    background: #f0fdf4;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-warning {
    background: #fffbeb;
    color: #92400e;
    border: 1px solid #fde68a;
}

.alert-info {
    background: #eff6ff;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* Cards */
.card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

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

.card-header {
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Tables */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-primary);
}

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

th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

td {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
}

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

/* Badge */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

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

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

.badge-warning {
    background: #fef3c7;
    color: #92400e;
}

.badge-info {
    background: #dbeafe;
    color: #1e40af;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-white);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.9;
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.stat-change {
    font-size: 0.85rem;
    opacity: 0.8;
}

/* Page Header */
.page-header {
    margin-bottom: 2rem;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}