:root {
    --color-bg: #f4f6f8;
    --color-surface: #ffffff;
    --color-border: #e2e5e9;
    --color-text: #1f2937;
    --color-muted: #6b7280;
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-success: #16a34a;
    --color-danger: #dc2626;
    --color-warning: #d97706;
    --sidebar-width: 230px;
    --radius: 8px;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
    margin: 0;
    font-family: 'Segoe UI', Tahoma, Arial, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    font-size: 14px;
    line-height: 1.5;
}

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

h1, h2, h3 { margin: 0 0 .6em; }

/* Layout */
.layout { display: flex; min-height: 100vh; }
.sidebar {
    width: var(--sidebar-width);
    background: #111827;
    color: #e5e7eb;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
}
.sidebar-brand {
    padding: 18px 16px;
    font-weight: 700;
    font-size: 15px;
    border-bottom: 1px solid rgba(255,255,255,.1);
}
.sidebar-nav { display: flex; flex-direction: column; padding: 8px; gap: 2px; }
.sidebar-nav a {
    color: #cbd5e1;
    padding: 10px 12px;
    border-radius: var(--radius);
}
.sidebar-nav a:hover { background: rgba(255,255,255,.08); text-decoration: none; color: #fff; }

.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.topbar {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 14px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 8px;
}
.topbar-title { font-size: 18px; font-weight: 600; }
.topbar-user { display: flex; align-items: center; gap: 14px; font-size: 13px; color: var(--color-muted); }
.lang-form { display: inline; }
.btn-link { background: none; border: none; color: var(--color-primary); cursor: pointer; font: inherit; padding: 0; }

.content { padding: 24px; max-width: 100%; overflow-x: auto; }

.auth-page { background: #111827; }
.auth-main { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 20px; }

/* Cards */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 20px;
}
.card-title { font-weight: 600; margin-bottom: 14px; font-size: 15px; }

.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }

.stat-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 18px; }
.stat-value { font-size: 26px; font-weight: 700; margin-top: 4px; }
.stat-label { color: var(--color-muted); font-size: 13px; }

/* Forms */
label { display: block; font-weight: 600; margin-bottom: 4px; font-size: 13px; }
.form-group { margin-bottom: 14px; }
input[type=text], input[type=search], input[type=password], input[type=number],
input[type=email], input[type=date], input[type=tel], select, textarea {
    width: 100%;
    padding: 9px 11px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: 14px;
    background: #fff;
    color: var(--color-text);
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--color-primary); outline-offset: 0; }
.form-row { display: flex; gap: 12px; flex-wrap: wrap; }
.form-row > * { flex: 1; min-width: 160px; }

.btn {
    display: inline-block;
    padding: 9px 18px;
    border-radius: var(--radius);
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-text);
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
}
.btn:hover { text-decoration: none; background: var(--color-bg); }
.btn-primary { background: var(--color-primary); border-color: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-danger { background: var(--color-danger); border-color: var(--color-danger); color: #fff; }
.btn-sm { padding: 5px 10px; font-size: 12px; }

/* Table */
table { width: 100%; border-collapse: collapse; background: var(--color-surface); }
th, td { padding: 10px 12px; border-bottom: 1px solid var(--color-border); text-align: start; font-size: 13.5px; }
th { color: var(--color-muted); font-weight: 600; background: #fafbfc; }
tr:hover td { background: #f9fafb; }
.table-wrap { overflow-x: auto; border: 1px solid var(--color-border); border-radius: var(--radius); }
.table-wrap table { border: none; }

.badge { display: inline-block; padding: 2px 9px; border-radius: 99px; font-size: 12px; font-weight: 600; }
.badge-success { background: #dcfce7; color: #166534; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-muted { background: #f1f5f9; color: #475569; }

.alert { padding: 12px 16px; border-radius: var(--radius); margin-bottom: 16px; font-size: 13.5px; }
.alert-success { background: #dcfce7; color: #14532d; border: 1px solid #bbf7d0; }
.alert-error { background: #fee2e2; color: #7f1d1d; border: 1px solid #fecaca; }

.text-muted { color: var(--color-muted); }
.text-danger { color: var(--color-danger); }
.text-end { text-align: end; }
.mt-0 { margin-top: 0; }
.toolbar { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 16px; flex-wrap: wrap; }

.login-card { width: 360px; max-width: 100%; }
.login-card .card-title { text-align: center; font-size: 18px; }

.invoice-items-table input { padding: 6px 8px; font-size: 13px; }
@media print {
    .no-print { display: none !important; }
    .sidebar, .topbar { display: none !important; }
    body { background: #fff; }
}