:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #eef2ff;
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --secondary: #64748b;
    --success: #10b981;
    --success-light: #ecfdf5;
    --warning: #f59e0b;
    --warning-light: #fffbeb;
    --danger: #ef4444;
    --danger-light: #fef2f2;
    --info: #0ea5e9;
    --info-light: #f0f9ff;
    
    --bg-body: #f8fafc;
    --bg-surface: #ffffff;
    --bg-sidebar: #1e1b4b; /* Deep Indigo/Purple */
    --bg-sidebar-hover: #312e81;
    --sidebar-text: #c7d2fe;
    --sidebar-active: #ffffff;
    
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    
    --border-color: #e2e8f0;
    --border-focus: #a5b4fc;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.03);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.5;
    font-size: 14px;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.15s ease-in-out;
}
a:hover {
    color: var(--primary-hover);
}

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

/* Sidebar */
.app-sidebar {
    width: 260px;
    background-color: var(--bg-sidebar);
    color: var(--sidebar-text);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    transition: all 0.3s ease;
    z-index: 100;
}

.sidebar-header {
    padding: 1.5rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.brand-icon {
    width: 36px;
    height: 36px;
    background: var(--primary-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 18px;
    box-shadow: 0 4px 10px rgba(99, 102, 241, 0.4);
}

.brand-title {
    font-size: 18px;
    font-weight: 700;
    color: #ffffff;
    letter-spacing: -0.5px;
}

.sidebar-menu {
    list-style: none;
    padding: 1rem 0.75rem;
    flex: 1;
    overflow-y: auto;
}

.menu-heading {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: #818cf8;
    padding: 0.75rem 0.75rem 0.25rem;
    font-weight: 600;
}

.menu-item {
    margin-bottom: 2px;
}

.menu-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.65rem 0.85rem;
    color: var(--sidebar-text);
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: all 0.2s;
}

.menu-link:hover {
    background-color: var(--bg-sidebar-hover);
    color: var(--sidebar-active);
}

.menu-link.active {
    background: var(--primary-gradient);
    color: #ffffff;
    box-shadow: 0 4px 8px rgba(99, 102, 241, 0.25);
}

.menu-icon {
    font-size: 16px;
    width: 20px;
    text-align: center;
}

.sidebar-footer {
    padding: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.merchant-badge {
    background: rgba(255, 255, 255, 0.06);
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Main Content Area */
.app-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

/* Navbar */
.app-navbar {
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    position: sticky;
    top: 0;
    z-index: 90;
}

.navbar-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.navbar-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.env-switch {
    display: inline-flex;
    background: #f1f5f9;
    padding: 3px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
}

.env-btn {
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 12px;
    font-weight: 600;
    border: none;
    background: transparent;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--text-secondary);
}

.env-btn.active.test {
    background: #f59e0b;
    color: #fff;
}

.env-btn.active.live {
    background: #10b981;
    color: #fff;
}

/* Content Container */
.app-content {
    padding: 1.75rem;
    flex: 1;
}

/* Cards */
.card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
    transition: box-shadow 0.2s;
}

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

.card-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
}

.card-body {
    padding: 1.25rem;
}

/* Metric / KPI Cards */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
    margin-bottom: 1.5rem;
}

.metric-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.metric-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
}

.metric-card.primary::before { background: var(--primary); }
.metric-card.success::before { background: var(--success); }
.metric-card.warning::before { background: var(--warning); }
.metric-card.danger::before { background: var(--danger); }
.metric-card.info::before { background: var(--info); }

.metric-label {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

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

.metric-sub {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.6rem;
    font-size: 11px;
    font-weight: 600;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.badge-success { background: var(--success-light); color: var(--success); }
.badge-warning { background: var(--warning-light); color: var(--warning); }
.badge-danger { background: var(--danger-light); color: var(--danger); }
.badge-info { background: var(--info-light); color: var(--info); }
.badge-secondary { background: #f1f5f9; color: var(--secondary); }
.badge-primary { background: var(--primary-light); color: var(--primary); }

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

.table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

.table th {
    background: #f8fafc;
    padding: 0.75rem 1rem;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.table td {
    padding: 0.85rem 1rem;
    border-bottom: 1px solid var(--border-color);
    vertical-align: middle;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--primary-hover);
    color: #fff;
}

.btn-secondary {
    background: #fff;
    border-color: var(--border-color);
    color: var(--text-primary);
}
.btn-secondary:hover {
    background: #f8fafc;
}

.btn-success { background: var(--success); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }

.btn-sm {
    padding: 0.25rem 0.6rem;
    font-size: 12px;
}

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

.form-label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.4rem;
}

.form-control, .form-select {
    width: 100%;
    padding: 0.55rem 0.75rem;
    font-size: 13px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: #fff;
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus, .form-select:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

/* Flash Messages */
.alert {
    padding: 0.85rem 1.25rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 13px;
}
.alert-success { background: var(--success-light); color: #065f46; border: 1px solid #a7f3d0; }
.alert-danger { background: var(--danger-light); color: #991b1b; border: 1px solid #fecaca; }
.alert-info { background: var(--info-light); color: #075985; border: 1px solid #bae6fd; }

/* Grid Utility */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }

@media (max-width: 900px) {
    .app-sidebar { width: 70px; }
    .brand-title, .menu-link span, .menu-heading { display: none; }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
}