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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #16a34a;
    --warning: #d97706;
    --danger: #dc2626;
    --info: #0891b2;
    --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;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gray-50);
    color: var(--gray-900);
    line-height: 1.5;
}

a {
    color: var(--primary);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* === Navbar === */
.navbar {
    background: white;
    border-bottom: 1px solid var(--gray-200);
    padding: 0 24px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-brand {
    display: flex;
    align-items: baseline;
    gap: 4px;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
}

.logo-sub {
    font-size: 14px;
    color: var(--gray-500);
}

.navbar-menu {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius);
    color: var(--gray-600);
    font-weight: 500;
    transition: all 0.15s;
}

.nav-link:hover {
    background: var(--gray-100);
    color: var(--gray-900);
    text-decoration: none;
}

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

.navbar-user {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--gray-600);
}

/* === Container === */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px;
}

/* === Page Header === */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.page-header h1 {
    font-size: 24px;
    font-weight: 600;
}

/* === Cards === */
.card {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-header h3 {
    font-size: 16px;
    font-weight: 600;
}

.card-body {
    padding: 20px;
}

.card-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--gray-200);
    background: var(--gray-50);
}

/* === Stats Grid === */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

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

.stat-card {
    background: white;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    text-align: center;
}

.stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--gray-900);
}

.stat-label {
    font-size: 14px;
    color: var(--gray-500);
    margin-top: 4px;
}

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

.table th,
.table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--gray-200);
}

.table th {
    font-weight: 600;
    color: var(--gray-600);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.table tbody tr:hover {
    background: var(--gray-50);
}

.table-sm th,
.table-sm td {
    padding: 8px 12px;
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 16px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius);
    border: 1px solid var(--gray-300);
    background: white;
    color: var(--gray-700);
    cursor: pointer;
    transition: all 0.15s;
}

.btn:hover {
    background: var(--gray-50);
    text-decoration: none;
}

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

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

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

.btn-success:hover {
    background: #15803d;
}

.btn-outline {
    background: transparent;
}

.btn-sm {
    padding: 4px 10px;
    font-size: 13px;
}

.btn-lg {
    padding: 12px 24px;
    font-size: 16px;
}

.btn-full {
    width: 100%;
}

/* === Forms === */
.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: var(--gray-700);
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 14px;
    transition: border-color 0.15s;
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.search-form,
.filter-form {
    display: flex;
    gap: 8px;
}

.search-input,
.select-input {
    padding: 8px 12px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 14px;
}

.search-input {
    min-width: 200px;
}

/* === Badges === */
.badge {
    display: inline-block;
    padding: 2px 8px;
    font-size: 12px;
    font-weight: 500;
    border-radius: 4px;
    background: var(--gray-100);
    color: var(--gray-700);
}

.badge-success {
    background: #dcfce7;
    color: #166534;
}

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

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

.badge-info {
    background: #cffafe;
    color: #0e7490;
}

.badge-lg {
    padding: 6px 12px;
    font-size: 14px;
}

/* === Alerts === */
.alert {
    padding: 12px 16px;
    border-radius: var(--radius);
    margin-bottom: 16px;
}

.alert-success {
    background: #dcfce7;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

/* === Utilities === */
.text-success { color: var(--success) !important; }
.text-danger { color: var(--danger) !important; }
.text-warning { color: var(--warning) !important; }
.text-muted { color: var(--gray-500) !important; }
.text-center { text-align: center; }
.text-sm { font-size: 13px; }

/* === Pagination === */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.pagination-info {
    color: var(--gray-500);
}

/* === Login === */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--gray-100) 0%, var(--gray-200) 100%);
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.login-box {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    padding: 32px;
}

.login-header {
    text-align: center;
    margin-bottom: 24px;
}

.login-header .logo {
    font-size: 32px;
}

/* === Tabs === */
.tabs {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.tab-buttons {
    display: flex;
    border-bottom: 1px solid var(--gray-200);
}

.tab-btn {
    padding: 12px 20px;
    background: none;
    border: none;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-600);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
}

.tab-btn:hover {
    color: var(--gray-900);
}

.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab-content {
    display: none;
    padding: 20px;
}

.tab-content.active {
    display: block;
}

/* === Charts === */
.chart-container {
    padding: 20px 0;
}

.chart-bars {
    display: flex;
    justify-content: space-around;
    align-items: flex-end;
    height: 120px;
    gap: 8px;
}

.chart-day {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.chart-bar-container {
    height: 100px;
    width: 100%;
    display: flex;
    gap: 4px;
    align-items: flex-end;
    justify-content: center;
}

.chart-bar {
    width: 20px;
    min-height: 4px;
    border-radius: 2px 2px 0 0;
    transition: height 0.3s;
}

.chart-bar-income {
    background: var(--success);
}

.chart-bar-usage {
    background: var(--warning);
}

.chart-label {
    margin-top: 8px;
    font-size: 12px;
    color: var(--gray-500);
}

.chart-legend {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-top: 16px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--gray-600);
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 2px;
}

.legend-income {
    background: var(--success);
}

.legend-usage {
    background: var(--warning);
}

/* === Topup === */
.topup-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.quick-buttons {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.quick-amount.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.user-info-box {
    margin-top: 8px;
    min-height: 24px;
}

.user-found {
    padding: 8px 12px;
    background: var(--gray-50);
    border-radius: var(--radius);
    font-size: 14px;
}

/* === Settings === */
.settings-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 24px;
}

.packages-list {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

pre {
    background: var(--gray-800);
    color: var(--gray-100);
    padding: 16px;
    border-radius: var(--radius);
    overflow-x: auto;
    font-size: 13px;
}

code {
    font-family: 'SF Mono', Monaco, monospace;
}

/* === Error page === */
.error-page {
    text-align: center;
    padding: 60px 20px;
}

.error-page h1 {
    font-size: 48px;
    margin-bottom: 16px;
}

/* === Responsive === */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .topup-grid,
    .settings-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-wrap: wrap;
        height: auto;
        padding: 12px;
    }
    
    .navbar-menu {
        width: 100%;
        order: 3;
        margin-top: 12px;
        overflow-x: auto;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .table {
        font-size: 13px;
    }
    
    .table th,
    .table td {
        padding: 8px;
    }
}