:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --background: #f8fafc;
    --card-bg: #ffffff;
    --sidebar-bg: #0f172a;
    --sidebar-hover: #1e293b;
    --sidebar-text: #94a3b8;
    --sidebar-text-active: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --danger: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.2s ease-in-out;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, sans-serif;
}

body {
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* ==================================================== */
/* LAYOUT GRID (Sidebar + Main)                         */
/* ==================================================== */
.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 260px;
    background: var(--sidebar-bg);
    color: var(--sidebar-text);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 50;
    transition: var(--transition);
}

.sidebar-header {
    padding: 1.5rem;
    font-size: 1.25rem;
    font-weight: 800;
    color: white;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    padding: 1rem;
    gap: 0.5rem;
    flex: 1;
}

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

.nav-item:hover {
    background: var(--sidebar-hover);
    color: var(--sidebar-text-active);
}

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

.main-content {
    flex: 1;
    margin-left: 260px; /* Offset for sidebar */
    min-width: 0; /* Prevent grid blowout */
    display: flex;
    flex-direction: column;
}

.top-header {
    background: var(--card-bg);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 40;
}

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

/* ==================================================== */
/* COMPONENTS                                           */
/* ==================================================== */
.card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border);
    padding: 1.5rem;
    transition: var(--transition);
}

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

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

.card-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-main);
}

/* Metrics Grid */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.metric-card {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    padding: 1.5rem;
}

.metric-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.metric-info h3 {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.metric-info p {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-main);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.39);
}

.btn-primary:hover {
    background: var(--primary-hover);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.23);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}

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

.btn-danger {
    background: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

/* Tables */
.table-container {
    overflow-x: auto;
    width: 100%;
}

.table {
    width: 100%;
    border-collapse: collapse;
    white-space: nowrap;
}

.table th, .table td {
    padding: 1rem 1.25rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.table th {
    background: var(--background);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 0.5px;
}

.table tbody tr {
    transition: var(--transition);
}

.table tbody tr:hover {
    background: #f8fafc;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-main);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: #fff;
    color: var(--text-main);
    font-size: 0.95rem;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Badges */
.badge {
    padding: 0.25rem 0.6rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.badge-success { background: #d1fae5; color: #047857; }
.badge-danger { background: #fee2e2; color: #b91c1c; }
.badge-warning { background: #fef3c7; color: #d97706; }
.badge-primary { background: #dbeafe; color: #1d4ed8; }