/* Modern CSS variables and reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --ink: #0f172a;
    --muted: #64748b;
    --border: #e6e9f0;
    --surface: #ffffff;
    --bg: #f4f6fb;
    --radius: 12px;
    --shadow-sm: 0 1px 2px 0 rgb(15 23 42 / 0.04), 0 1px 3px 0 rgb(15 23 42 / 0.06);
    --shadow-md: 0 4px 10px -2px rgb(15 23 42 / 0.08), 0 2px 6px -2px rgb(15 23 42 / 0.06);
    --shadow-lg: 0 12px 24px -8px rgb(15 23 42 / 0.18);
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg);
    background-image: radial-gradient(circle at 0% 0%, rgb(99 102 241 / 0.06), transparent 40%),
        radial-gradient(circle at 100% 0%, rgb(236 72 153 / 0.05), transparent 40%);
    color: var(--ink);
    line-height: 1.5;
}

/* Nav styles */
.main-nav {
    background: linear-gradient(135deg, var(--primary-color, #4f46e5), var(--secondary-color, #4338ca));
    border-bottom: none;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1440px;
    margin: 0 auto;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    padding: 0.75rem 1.5rem;
    gap: 2rem;
}

.brand-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    gap: 0.65rem;
}

.nav-logo {
    height: 48px;
    width: auto;
    border-radius: 8px;
    background: rgb(255 255 255 / 0.9);
    padding: 2px;
}

.brand-name {
    font-size: 1.2rem;
    font-weight: 700;
    color: #ffffff;
    letter-spacing: -0.01em;
}

.nav-links {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    width: 100%;
    flex-wrap: wrap;
}

.nav-links a {
    text-decoration: none;
    color: rgb(255 255 255 / 0.82);
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.75rem;
    border-radius: 8px;
    white-space: nowrap;
}

.nav-links a:hover {
    color: #ffffff;
    background-color: rgb(255 255 255 / 0.14);
}

.user-menu {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

.user-greeting {
    font-size: 0.875rem;
    color: rgb(255 255 255 / 0.85);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

/* Dropdown */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: var(--surface);
    min-width: 190px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    z-index: 101;
    top: 100%;
    overflow: hidden;
    padding: 0.35rem;
}

.dropdown-content a {
    color: var(--ink);
    padding: 0.6rem 0.75rem;
    display: flex;
    border-radius: 8px;
}

.dropdown-content a:hover {
    background-color: #eef2ff;
    color: #4338ca;
}

.dropdown:hover .dropdown-content {
    display: block;
}

.dropdown-right .dropdown-content {
    right: 0;
    left: auto;
}


/* Page layouts */
.main-content {
    max-width: 1440px;
    margin: 2rem auto;
    padding: 0 1.5rem;
    min-height: calc(100vh - 180px);
}

.main-footer {
    background-color: var(--surface);
    border-top: 1px solid var(--border);
    padding: 1.5rem;
    text-align: center;
    color: var(--muted);
    font-size: 0.875rem;
    margin-top: 2rem;
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-danger, .nav-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    padding: 0.55rem 1.1rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 999px;
    border: none;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color, #4f46e5), var(--secondary-color, #4338ca));
    color: #ffffff;
    box-shadow: var(--shadow-sm);
}
.btn-primary:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: #eef1f8;
    color: #334155;
}
.btn-secondary:hover {
    background-color: #e2e6f0;
}

.btn-danger {
    background-color: #fee2e2;
    color: #b91c1c;
}
.btn-danger:hover {
    background-color: #fecaca;
}

.nav-btn {
    padding: 0.4rem 0.85rem;
    font-size: 0.8rem;
    border-radius: 999px;
}

.main-nav .nav-btn.btn-danger, .main-nav .nav-btn.btn-secondary {
    background-color: rgb(255 255 255 / 0.16);
    color: #ffffff;
}
.main-nav .nav-btn.btn-danger:hover, .main-nav .nav-btn.btn-secondary:hover {
    background-color: rgb(255 255 255 / 0.28);
}

/* Grid & Cards */
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.2s, transform 0.2s;
}

.kpi-card {
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
    position: relative;
    overflow: hidden;
    border-left: none !important;
}

.kpi-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.kpi-icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: #ffffff;
    box-shadow: var(--shadow-sm);
}

.kpi-icon.blue { background: linear-gradient(135deg, #60a5fa, #2563eb); }
.kpi-icon.green { background: linear-gradient(135deg, #34d399, #059669); }
.kpi-icon.amber { background: linear-gradient(135deg, #fbbf24, #d97706); }
.kpi-icon.purple { background: linear-gradient(135deg, #a78bfa, #7c3aed); }
.kpi-icon.pink { background: linear-gradient(135deg, #f472b6, #db2777); }
.kpi-icon.teal { background: linear-gradient(135deg, #2dd4bf, #0d9488); }
.kpi-icon.indigo { background: linear-gradient(135deg, #818cf8, #4f46e5); }
.kpi-icon.red { background: linear-gradient(135deg, #f87171, #dc2626); }

.kpi-label {
    font-size: 0.85rem;
    color: var(--muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.kpi-value {
    font-size: 1.85rem;
    font-weight: 800;
    color: var(--ink);
    letter-spacing: -0.01em;
}

.kpi-subtitle {
    font-size: 0.8rem;
    color: #94a3b8;
}

/* Section headers - Upgraded premium styling */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border);
    flex-wrap: wrap;
    gap: 1rem;
}

.section-title {
    font-size: 1.65rem;
    font-weight: 800;
    color: var(--ink);
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.section-title i {
    color: var(--primary-color, #4f46e5);
    background: rgb(79 70 229 / 0.08);
    width: 42px;
    height: 42px;
    border-radius: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35rem;
}

/* Collapsible Filter Panel */
.filter-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.filter-panel summary {
    padding: 0.85rem 1.25rem;
    font-weight: 600;
    color: var(--ink);
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #f8fafc;
    user-select: none;
}

.filter-panel summary::-webkit-details-marker {
    display: none;
}

.filter-panel summary:hover {
    background-color: #f1f5f9;
}

.filter-panel[open] summary {
    border-bottom: 1px solid var(--border);
}

.filter-panel .toggle-icon {
    font-size: 0.85rem;
    transition: transform 0.2s;
}

.filter-panel[open] .toggle-icon {
    transform: rotate(180deg);
}

.filter-content {
    padding: 1.25rem;
    display: flex;
    gap: 1rem;
    align-items: flex-end;
    flex-wrap: wrap;
}

.filter-content .form-group {
    flex: 1;
    min-width: 200px;
    margin-bottom: 0;
}

/* Collapsible Ledger Panel */
.ledger-details {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.ledger-summary {
    padding: 1.1rem 1.5rem;
    font-weight: 700;
    color: var(--ink);
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #f8fafc;
    user-select: none;
}

.ledger-summary::-webkit-details-marker {
    display: none;
}

.ledger-summary:hover {
    background-color: #f1f5f9;
}

.ledger-details[open] .ledger-summary {
    border-bottom: 1px solid var(--border);
}

.ledger-details .toggle-icon {
    transition: transform 0.2s;
}

.ledger-details[open] .toggle-icon {
    transform: rotate(180deg);
}

/* Chart Styles */
.chart-card {
    padding: 1.5rem;
}

.chart-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--ink);
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.chart-title i {
    color: var(--primary-color, #4f46e5);
}

.chart-container {
    position: relative;
    height: 350px;
    width: 100%;
}

/* Sub-nav tabs */
.nav-tab {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 1rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--muted);
    text-decoration: none;
    background-color: #eef1f8;
    transition: all 0.2s;
}

.nav-tab:hover {
    background-color: #e2e6f0;
}

.nav-tab.active {
    background: linear-gradient(135deg, var(--primary-color, #4f46e5), var(--secondary-color, #4338ca));
    color: #ffffff;
}

/* Tables */
.table-container {
    overflow-x: auto;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 0.875rem;
}

th, td {
    padding: 0.85rem 1.1rem;
    border-bottom: 1px solid var(--border);
}

th {
    background-color: #f8fafc;
    color: #475569;
    font-weight: 700;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

tbody tr {
    transition: background-color 0.15s;
}

tbody tr:hover td {
    background-color: #f5f6fe;
}

tbody tr:last-child td {
    border-bottom: none;
}

/* Forms styling */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: #334155;
}

.form-control {
    padding: 0.65rem 0.9rem;
    font-size: 0.875rem;
    border: 1px solid #d8dce8;
    border-radius: 9px;
    background-color: #ffffff;
    transition: border-color 0.2s, box-shadow 0.2s;
    width: 100%;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color, #4f46e5);
    box-shadow: 0 0 0 3px rgb(79 70 229 / 0.12);
}

.form-checkbox {
    flex-direction: row;
    align-items: center;
    gap: 0.75rem;
}

.form-checkbox input {
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color, #4f46e5);
}

/* Alert styles */
.alert {
    padding: 0.8rem 1.1rem;
    border-radius: 10px;
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.alert-danger {
    background-color: #fef2f2;
    color: #b91c1c;
    border: 1px solid #fee2e2;
}

.alert-success {
    background-color: #f0fdf4;
    color: #15803d;
    border: 1px solid #dcfce7;
}

/* Filters bar */
.filter-bar {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem 1.25rem;
    display: flex;
    gap: 1rem;
    align-items: flex-end;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.filter-bar .form-group {
    flex: 1;
    min-width: 200px;
}

/* Ledger Matrix */
.matrix-table th, .matrix-table td {
    padding: 0.5rem;
    text-align: center;
}

.status-cell {
    font-weight: 700;
    font-size: 0.72rem;
    padding: 0.3rem 0.6rem;
    border-radius: 999px;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.status-paid {
    background-color: #dcfce7;
    color: #15803d;
    cursor: pointer;
}

.status-unpaid {
    background-color: #fef2f2;
    color: #b91c1c;
    cursor: pointer;
}

.cell-amount {
    font-weight: 600;
}