:root {
    --bg: #f4f7fb;
    --card: #ffffff;
    --text: #1f2937;
    --muted: #64748b;
    --border: #dbe4ee;
    --primary: #2563eb;
    --primary-soft: #dbeafe;
    --danger: #dc2626;
    --success: #15803d;
    --warning: #d97706;
    --shadow: 0 18px 40px rgba(15, 23, 42, 0.08);
    --radius: 16px;
    --radius-sm: 12px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Inter, system-ui, "Segoe UI", sans-serif;
    background: linear-gradient(180deg, #f8fbff 0%, #f3f6fb 100%);
    color: var(--text);
}

a {
    color: inherit;
    text-decoration: none;
}

.app-shell {
    display: grid;
    grid-template-columns: 260px 1fr;
    min-height: 100vh;
}

.sidebar {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(14px);
    border-right: 1px solid rgba(219, 228, 238, 0.8);
    padding: 28px 20px;
}

.brand {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 24px;
}

.nav-link {
    display: block;
    padding: 12px 14px;
    margin-bottom: 8px;
    border-radius: var(--radius-sm);
    color: var(--muted);
}

.nav-link.active,
.nav-link:hover {
    background: var(--primary-soft);
    color: var(--primary);
}

.content {
    padding: 28px;
}

.page-header,
.toolbar,
.card,
.stat-card,
.auth-card {
    background: var(--card);
    border: 1px solid rgba(219, 228, 238, 0.7);
    box-shadow: var(--shadow);
    border-radius: var(--radius);
}

.page-header,
.toolbar,
.card,
.auth-card {
    padding: 22px;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
}

.page-title {
    margin: 0;
    font-size: 1.7rem;
}

.page-subtitle {
    margin: 6px 0 0;
    color: var(--muted);
}

.actions,
.inline-actions,
.form-grid,
.stats-grid,
.dashboard-grid {
    display: grid;
    gap: 16px;
}

.actions {
    grid-auto-flow: column;
    align-items: center;
    justify-content: end;
}

.stats-grid {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    margin-bottom: 24px;
}

.dashboard-grid {
    grid-template-columns: 1.6fr 1fr;
}

.stat-card {
    padding: 18px;
}

.stat-label {
    color: var(--muted);
    font-size: 0.9rem;
}

.stat-value {
    margin-top: 10px;
    font-size: 1.9rem;
    font-weight: 700;
}

.card + .card,
.toolbar + .card {
    margin-top: 20px;
}

.form-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.form-grid.single {
    grid-template-columns: 1fr;
}

.field {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.field label {
    font-size: 0.92rem;
    font-weight: 600;
}

input,
select,
textarea,
button {
    font: inherit;
}

input,
select,
textarea {
    width: 100%;
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: #fbfdff;
    color: var(--text);
}

textarea {
    min-height: 110px;
    resize: vertical;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 11px 16px;
    border: 0;
    border-radius: 999px;
    cursor: pointer;
    font-weight: 600;
}

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

.btn-secondary {
    background: #eef2f8;
    color: var(--text);
}

.btn-danger {
    background: #fee2e2;
    color: var(--danger);
}

.btn-success {
    background: #dcfce7;
    color: var(--success);
}

.table-wrap {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th,
td {
    padding: 14px 10px;
    border-bottom: 1px solid #edf2f7;
    text-align: left;
    vertical-align: top;
}

th {
    color: var(--muted);
    font-size: 0.88rem;
    font-weight: 600;
}

.badge {
    display: inline-flex;
    padding: 6px 10px;
    border-radius: 999px;
    font-size: 0.82rem;
    font-weight: 700;
}

.badge-pending {
    background: #dbeafe;
    color: #1d4ed8;
}

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

.badge-overdue {
    background: #fee2e2;
    color: #b91c1c;
}

.badge-partial {
    background: #fef3c7;
    color: #b45309;
}

.badge-cancelled {
    background: #e5e7eb;
    color: #4b5563;
}

.flash {
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 18px;
}

.flash-success {
    background: #ecfdf5;
    color: #166534;
}

.flash-error {
    background: #fef2f2;
    color: #991b1b;
}

.auth-page {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
}

.auth-card {
    width: min(420px, 100%);
}

.muted {
    color: var(--muted);
}

.link-row,
.table-actions,
.split {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
}

.split {
    justify-content: space-between;
}

.empty-state {
    padding: 26px;
    text-align: center;
    color: var(--muted);
}

.pagination {
    display: flex;
    gap: 8px;
    justify-content: end;
    margin-top: 18px;
}

@media (max-width: 980px) {
    .app-shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        border-right: 0;
        border-bottom: 1px solid rgba(219, 228, 238, 0.8);
    }

    .dashboard-grid,
    .form-grid {
        grid-template-columns: 1fr;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .actions {
        grid-auto-flow: row;
        justify-content: stretch;
        width: 100%;
    }
}