:root {
    --primary-color: #1e40af;
    --secondary-color: #0f172a;
    --bg-main: #f8fafc;
    --card-bg: #ffffff;
    --text-dark: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
}

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

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

/* Header & Branding */
.navbar {
    background-color: var(--secondary-color);
    color: #ffffff;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: #ffffff;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.brand-badge {
    background-color: var(--primary-color);
    color: #ffffff;
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: 9999px;
    text-transform: uppercase;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    list-style: none;
}

.nav-link {
    color: #cbd5e1;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover, .nav-link.active {
    color: #ffffff;
}

.btn-logout {
    background-color: rgba(255,255,255,0.1);
    color: #ffffff;
    border: 1px solid rgba(255,255,255,0.2);
    padding: 0.4rem 1rem;
    border-radius: 0.375rem;
    text-decoration: none;
    font-size: 0.875rem;
}

.btn-logout:hover {
    background-color: var(--danger-color);
    border-color: var(--danger-color);
}

/* Layout */
.app-container {
    display: flex;
    min-height: calc(100vh - 64px);
}

.sidebar {
    width: 260px;
    background-color: #ffffff;
    border-right: 1px solid var(--border-color);
    padding: 1.5rem 1rem;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-item {
    margin-bottom: 0.5rem;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--text-dark);
    text-decoration: none;
    border-radius: 0.375rem;
    font-weight: 500;
}

.sidebar-link:hover, .sidebar-link.active {
    background-color: rgba(30, 64, 175, 0.08);
    color: var(--primary-color);
}

.main-content {
    flex: 1;
    padding: 2rem;
}

/* UI Cards & Utilities */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 1.5rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    margin-bottom: 1.5rem;
}

.card-header {
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.btn-primary {
    background-color: var(--primary-color);
    color: #ffffff;
    padding: 0.5rem 1.25rem;
    border: none;
    border-radius: 0.375rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}

.btn-primary:hover {
    opacity: 0.9;
}

.alert {
    padding: 1rem;
    border-radius: 0.375rem;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

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

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

/* Progress bar */
.progress-bar-bg {
    width: 100%;
    height: 10px;
    background-color: #e2e8f0;
    border-radius: 5px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

/* Table styling */
.data-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

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

.data-table th {
    background-color: #f1f5f9;
    font-weight: 600;
    color: var(--text-dark);
}

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

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}