:root {
    --bg: #f4f6f8;
    --panel: #ffffff;
    --text: #1f2937;
    --muted: #6b7280;
    --border: #e5e7eb;
    --primary: #0f766e;
    --primary-dark: #115e59;
    --danger: #dc2626;
    --success: #15803d;
    --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: var(--bg);
    color: var(--text);
}

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

label {
    display: block;
    margin-bottom: 6px;
    color: #374151;
    font-size: 14px;
    font-weight: 700;
}

input,
select,
textarea {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 11px 12px;
    font-size: 14px;
    background: #fff;
}

button,
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    border: 0;
    border-radius: 8px;
    padding: 10px 14px;
    background: #e5e7eb;
    color: #111827;
    font-weight: 700;
    cursor: pointer;
}

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

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

.btn-light {
    background: #f3f4f6;
    color: #111827;
}

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

.btn-sm {
    padding: 6px 10px;
    font-size: 12px;
}

.full {
    width: 100%;
}

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

.sidebar {
    position: sticky;
    top: 0;
    height: 100vh;
    background: #111827;
    color: #fff;
    padding: 22px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 28px;
}

.brand-mark {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border-radius: 8px;
    background: var(--primary);
    font-size: 22px;
    font-weight: 800;
}

.brand small {
    display: block;
    margin-top: 3px;
    color: #cbd5e1;
}

.sidebar nav {
    display: grid;
    gap: 7px;
}

.sidebar nav a {
    display: block;
    padding: 11px 12px;
    border-radius: 8px;
    color: #d1d5db;
    font-weight: 700;
}

.sidebar nav a.active,
.sidebar nav a:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.main {
    min-width: 0;
    padding: 24px;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    margin-bottom: 22px;
}

.topbar h1 {
    margin: 0 0 4px;
    font-size: 28px;
}

.topbar span,
.muted {
    color: var(--muted);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 10px;
}

.panel {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 18px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 16px;
}

.panel-header h2 {
    margin: 0;
    font-size: 18px;
}

.grid-form {
    display: grid;
    grid-template-columns: repeat(4, minmax(150px, 1fr));
    gap: 14px;
    align-items: end;
}

.grid-form.compact {
    grid-template-columns: repeat(3, minmax(160px, 260px));
}

.span-2 {
    grid-column: span 2;
}

.form-actions {
    display: flex;
    gap: 10px;
    align-items: end;
}

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

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

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

th,
td {
    padding: 12px 10px;
    border-bottom: 1px solid var(--border);
    text-align: left;
    vertical-align: middle;
}

th {
    color: #374151;
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

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

.actions form {
    margin: 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(160px, 1fr));
    gap: 16px;
    margin-bottom: 20px;
}

.stat-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 18px;
    box-shadow: var(--shadow);
}

.stat-card span {
    color: var(--muted);
    font-size: 14px;
}

.stat-card strong {
    display: block;
    margin-top: 8px;
    font-size: 26px;
}

.two-column {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 20px;
}

.badge {
    display: inline-block;
    border-radius: 999px;
    padding: 4px 9px;
    font-size: 12px;
    font-weight: 800;
}

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

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

.alert {
    border-radius: 8px;
    padding: 12px 14px;
    margin-bottom: 16px;
    font-weight: 700;
}

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

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

.sale-items {
    margin: 16px 0;
}

.checkout-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(130px, 1fr)) minmax(220px, 320px);
    gap: 14px;
    margin: 16px 0;
    align-items: end;
}

.summary-box {
    display: grid;
    gap: 6px;
    padding: 12px;
    border-radius: 8px;
    background: #f9fafb;
    border: 1px solid var(--border);
}

.summary-box span {
    display: flex;
    justify-content: space-between;
}

.footer {
    margin-top: 24px;
    color: var(--muted);
    font-size: 13px;
}

.login-body {
    min-height: 100vh;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #ecfeff, #f8fafc);
    padding: 20px;
}

.login-card {
    width: min(420px, 100%);
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 28px;
    box-shadow: var(--shadow);
}

.login-card.wide {
    width: min(540px, 100%);
}

.login-card h1 {
    margin: 0 0 6px;
}

.login-card p {
    margin: 0 0 20px;
    color: var(--muted);
}

.login-card form {
    display: grid;
    gap: 12px;
}

.login-card small {
    display: block;
    margin-top: 14px;
    color: var(--muted);
}

.receipt-body {
    background: #f9fafb;
    padding: 20px;
}

.receipt {
    width: min(760px, 100%);
    margin: 0 auto;
    background: #fff;
    border-radius: 8px;
    padding: 24px;
    border: 1px solid var(--border);
}

.receipt-head {
    text-align: center;
    border-bottom: 1px dashed #d1d5db;
    margin-bottom: 14px;
    padding-bottom: 14px;
}

.receipt-head h1,
.receipt-head p {
    margin: 3px 0;
}

.receipt-meta {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-bottom: 14px;
    font-size: 14px;
}

.receipt-total {
    width: min(320px, 100%);
    margin-left: auto;
    display: grid;
    gap: 8px;
    padding-top: 14px;
}

.receipt-total span {
    display: flex;
    justify-content: space-between;
}

.receipt-actions {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 18px;
}

@media (max-width: 900px) {
    .app-shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
        height: auto;
    }

    .sidebar nav {
        grid-template-columns: repeat(2, 1fr);
    }

    .topbar,
    .panel-header,
    .user-menu {
        align-items: flex-start;
        flex-direction: column;
    }

    .grid-form,
    .stats-grid,
    .two-column,
    .checkout-grid,
    .grid-form.compact {
        grid-template-columns: 1fr;
    }

    .span-2 {
        grid-column: auto;
    }
}

@media print {
    .sidebar,
    .topbar,
    .footer,
    .receipt-actions,
    .no-print {
        display: none !important;
    }

    .app-shell,
    .main {
        display: block;
        padding: 0;
    }

    .panel,
    .stat-card,
    .receipt {
        box-shadow: none;
        border: 0;
    }
}