:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --success: #10b981;
    --success-bg: #d1fae5;
    --warning: #f59e0b;
    --warning-bg: #fef3c7;
    --danger: #ef4444;
    --danger-bg: #fee2e2;
    --info: #3b82f6;
    --info-bg: #dbeafe;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.05), 0 2px 4px -2px rgb(0 0 0 / 0.05);
    --shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -2px rgb(0 0 0 / 0.04);
    --font: 'Inter', system-ui, sans-serif;
}

/* Global Styles */
.page-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-main);
}
.report-actions {
    display: flex;
    gap: 0.75rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text-main);
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-primary { background: var(--primary); color: white; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); }

/* Filters Bar */
.filters-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    background: var(--card-bg);
    padding: 1rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}
.filter-select, .filter-input {
    padding: 0.6rem 0.8rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.875rem;
    background: #fff;
    color: var(--text-main);
}
.filter-input[type="date"] { min-width: 150px; }
.filters-bar .btn { margin-left: auto; }

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.stat-card {
    background: var(--card-bg);
    padding: 1.25rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }
.stat-info h3 { font-size: 0.875rem; color: var(--text-muted); font-weight: 500; margin-bottom: 0.25rem; }
.stat-info p { font-size: 1.5rem; font-weight: 700; margin-bottom: 0.5rem; }
.stat-icon {
    width: 40px;
    height: 40px;
    background: #f1f5f9;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}
.trend { font-size: 0.8rem; font-weight: 600; padding: 2px 6px; border-radius: 4px; }
.trend-up { color: var(--success); background: var(--success-bg); }
.trend-down { color: var(--danger); background: var(--danger-bg); }

/* Charts Grid */
.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.chart-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}
.table-header {
    padding: 1rem 1.25rem;
    font-weight: 600;
    border-bottom: 1px solid var(--border);
    background: #f8fafc;
}
.chart-placeholder {
    height: 280px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: repeating-linear-gradient(
        45deg,
        #f8fafc,
        #f8fafc 10px,
        #f1f5f9 10px,
        #f1f5f9 20px
    );
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Table */
.recent-table {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    margin-bottom: 2rem;
}
table { width: 100%; border-collapse: collapse; }
thead th {
    text-align: left;
    padding: 1rem 1.25rem;
    background: #f8fafc;
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--border);
}
tbody td {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-main);
    font-size: 0.9rem;
}
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: #fafbfc; }

/* Status Badges */
.status-badge {
    display: inline-block;
    padding: 0.35rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: capitalize;
}
.status-paid { background: var(--success-bg); color: #065f46; }
.status-pending { background: var(--warning-bg); color: #92400e; }
.status-overdue { background: var(--danger-bg); color: #991b1b; }
.status-high { background: var(--info-bg); color: #1e40af; }

/* Responsive */
@media (max-width: 768px) {
    .page-header, .filters-bar, .charts-grid { flex-direction: column; align-items: stretch; }
    .report-actions, .filters-bar .btn { margin-left: 0; }
    .filters-bar { gap: 0.75rem; }
    table { display: block; overflow-x: auto; white-space: nowrap; }
}