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

:root {
    --primary-color: #0078d4;
    --primary-hover: #106ebe;
    --success-color: #107c10;
    --warning-color: #ff8c00;
    --danger-color: #d13438;
    --text-color: #323130;
    --text-secondary: #605e5c;
    --border-color: #edebe9;
    --bg-light: #faf9f8;
    --sidebar-bg: #f3f2f1;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-color);
    line-height: 1.5;
}

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

.login-container {
    background: white;
    padding: 3rem;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    text-align: center;
    max-width: 400px;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.logo p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

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

.sidebar {
    width: 260px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

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

.sidebar-header h2 {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.user-info {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.nav-menu {
    list-style: none;
    flex: 1;
    padding: 1rem 0;
}

.nav-menu li {
    margin: 0.25rem 0.75rem;
}

.nav-menu a {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    color: var(--text-color);
    text-decoration: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s;
}

.nav-menu a:hover {
    background: rgba(0, 120, 212, 0.1);
}

.nav-menu li.active a {
    background: var(--primary-color);
    color: white;
}

.nav-menu a span {
    margin-right: 0.75rem;
    font-size: 1.25rem;
}

.sidebar-footer {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

.main-content {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
    background: white;
}

/* Buttons */
.btn {
    padding: 0.5rem 1.5rem;
    border: none;
    border-radius: 6px;
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

.btn-secondary {
    background: var(--bg-light);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover:not(:disabled) {
    background: #e1dfdd;
}

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

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

.btn-sm {
    padding: 0.375rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 0.75rem 2rem;
    font-size: 1rem;
}

/* Cards */
.card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

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

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.875rem;
}

.form-control {
    width: 100%;
    padding: 0.625rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 0.9375rem;
    transition: border-color 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 120, 212, 0.1);
}

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

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

.table th {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-success {
    background: #e6f4ea;
    color: var(--success-color);
}

.badge-warning {
    background: #fef7e0;
    color: var(--warning-color);
}

.badge-danger {
    background: #fce8e6;
    color: var(--danger-color);
}

.badge-secondary {
    background: var(--bg-light);
    color: var(--text-secondary);
}

/* Search bar */
.search-bar {
    position: relative;
    margin-bottom: 1.5rem;
}

.search-bar input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9375rem;
}

.search-bar::before {
    content: "🔍";
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 6px;
    margin-bottom: 1rem;
}

.alert-success {
    background: #e6f4ea;
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

.alert-danger {
    background: #fce8e6;
    color: var(--danger-color);
    border: 1px solid var(--danger-color);
}

.alert-info {
    background: #e3f2fd;
    color: #0277bd;
    border: 1px solid #0277bd;
}

/* Loading spinner */
.spinner {
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

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

.stat-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    .app-layout {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
    }
    
    .main-content {
        padding: 1rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}