:root {
    --bg: #f6f7f9;
    --panel: #ffffff;
    --text: #1e293b;
    --muted: #64748b;
    --border: #e2e8f0;
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --green: #10b981;
    --amber: #f59e0b;
    --red: #ef4444;
    --radius: 10px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 15px;
    color: var(--text);
    background: var(--bg);
    line-height: 1.5;
}

.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* topbar */
.topbar { background: #0f172a; color: #e2e8f0; }
.topbar-inner { display: flex; align-items: center; gap: 28px; height: 54px; }
.brand { color: #fff; text-decoration: none; font-size: 17px; }
.brand .muted { color: #64748b; font-size: 13px; }
.topbar nav { display: flex; gap: 4px; flex: 1; }
.topbar nav a {
    color: #cbd5e1; text-decoration: none; padding: 6px 14px; border-radius: 7px; font-size: 14px;
}
.topbar nav a:hover { background: #1e293b; color: #fff; }
.topbar nav a.active { background: #1e293b; color: #fff; font-weight: 600; }
.logout-form { margin: 0; }

h1 { font-size: 24px; margin: 26px 0 18px; }
h2 { font-size: 16px; margin: 0 0 14px; }
h2 .right { float: right; }

.muted { color: var(--muted); }
.small { font-size: 13px; }
.num { text-align: right; }
.text-green { color: #059669; }
.text-amber { color: #d97706; }
.text-red { color: #dc2626; }

/* cards */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px; margin-bottom: 18px; }
.card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 18px; }
.card-label { font-size: 13px; color: var(--muted); margin-bottom: 2px; }
.card-value { font-size: 22px; font-weight: 700; }

.panel { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; margin-bottom: 18px; }
.panel svg { width: 100%; height: auto; }

/* tables */
.table { width: 100%; border-collapse: collapse; }
.table th {
    text-align: left; font-size: 12px; text-transform: uppercase; letter-spacing: 0.4px;
    color: var(--muted); padding: 8px 10px; border-bottom: 2px solid var(--border);
}
.table th.num { text-align: right; }
.table td { padding: 9px 10px; border-bottom: 1px solid var(--border); vertical-align: middle; }
.table tr:hover td { background: #f8fafc; }
.table a { color: var(--primary); text-decoration: none; font-weight: 600; }
.table a:hover { text-decoration: underline; }
.table form { margin: 0; display: inline; }

/* badges */
.badge {
    display: inline-block; font-size: 12px; font-weight: 600; padding: 2px 9px; border-radius: 20px;
}
.badge-issued { background: #fef3c7; color: #92400e; }
.badge-paid { background: #d1fae5; color: #065f46; }
.badge-draft { background: #e2e8f0; color: #475569; }
.badge-overdue { background: #fee2e2; color: #991b1b; }
.badge-rc { background: #ede9fe; color: #5b21b6; margin-left: 4px; }

/* flash */
.flash {
    background: #d1fae5; color: #065f46; border: 1px solid #a7f3d0;
    padding: 10px 16px; border-radius: var(--radius); margin: 16px 0;
}
.flash-error { background: #fee2e2; color: #991b1b; border-color: #fecaca; }

/* buttons */
.btn {
    display: inline-block; background: var(--panel); color: var(--text);
    border: 1px solid var(--border); border-radius: 8px; padding: 8px 16px;
    font-size: 14px; font-weight: 600; text-decoration: none; cursor: pointer;
}
.btn:hover { background: #f1f5f9; }
.btn-primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-green { background: var(--green); border-color: var(--green); color: #fff; }
.btn-green:hover { background: #059669; }
.btn-danger { background: #fff; border-color: #fca5a5; color: #dc2626; }
.btn-danger:hover { background: #fef2f2; }
.btn-sm { padding: 4px 10px; font-size: 13px; }
.btn-link { background: none; border: none; color: var(--primary); cursor: pointer; padding: 0; font-size: 14px; }
.btn-link:hover { text-decoration: underline; }
.topbar .btn-link { color: #94a3b8; }
.topbar .btn-link:hover { color: #fff; text-decoration: none; }

/* forms */
form.narrow { max-width: 620px; }
fieldset {
    background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 16px 20px 20px; margin: 0 0 16px;
}
legend { font-weight: 700; font-size: 14px; padding: 0 6px; }
label { display: block; margin: 10px 0 0; font-size: 13.5px; font-weight: 600; color: #334155; }
input, select, textarea {
    display: block; width: 100%; margin-top: 4px; padding: 8px 10px;
    border: 1px solid #cbd5e1; border-radius: 7px; font-size: 14.5px; font-family: inherit;
    background: #fff; color: var(--text);
}
input:focus, select:focus, textarea:focus {
    outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}
.checkbox-label { display: flex; align-items: center; gap: 8px; margin-top: 24px; }
.checkbox-label input { width: auto; margin: 0; }
.input-group { display: flex; gap: 6px; align-items: stretch; }
.input-group input { flex: 1; }
.input-group .btn { white-space: nowrap; }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 16px; align-items: start; }
@media (max-width: 720px) { .grid-2 { grid-template-columns: 1fr; } }

.toolbar { display: flex; gap: 10px; align-items: center; margin: 18px 0; flex-wrap: wrap; }
.toolbar form { margin: 0; }
.filters { display: flex; gap: 8px; flex: 1; }
.filters select { width: auto; margin: 0; }

/* items table in invoice form */
.items-table input { margin: 0; }
.items-table td { padding: 5px 4px; }

/* auth pages */
.auth-body { display: flex; align-items: center; justify-content: center; min-height: 100vh; background: #0f172a; }
.auth-card {
    background: var(--panel); border-radius: 14px; padding: 34px 38px; width: 380px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}
.auth-card h1 { margin: 0 0 10px; font-size: 22px; }
.auth-card .btn { width: 100%; margin-top: 18px; }