:root {
  /* Ledger ink — near-black with a green bias, not a neutral gray */
  --ink: #181d17;
  --ink-soft: #3c463c;
  --muted: #5f6b5c;
  --bg: #eef0e9;
  --panel: #fbfcf8;
  --border: #d9ddcf;
  --border-strong: #b9c0ab;
  /* Ledger green — bookkeeper's "in the black" ink */
  --accent: #1f4d3a;
  --accent-dark: #123526;
  --accent-soft: #e2ebe1;
  /* Stamped sepia for open items, brick ink for overdue */
  --open: #8a5a24;
  --open-soft: #f3e9d7;
  --danger: #8c2f28;
  --danger-soft: #f4e3df;
  --text: #181d17;
  --radius: 3px;
  --radius-lg: 6px;
  --font-display: ui-serif, Georgia, "Times New Roman", Times, serif;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.5;
  background-image: linear-gradient(var(--border) 1px, transparent 1px);
  background-size: 100% 2.4em;
  background-attachment: local;
}

h1, h2, h3 { font-family: var(--font-display); letter-spacing: 0.01em; text-wrap: balance; }

::selection { background: var(--accent-soft); color: var(--accent-dark); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

/* Topbar — ledger cover: ink black, a single stamped ring as mark */
.topbar {
  background: var(--ink);
  color: #fff;
  border-bottom: 3px solid var(--accent);
}
.topbar-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
  font-size: 17px;
  font-family: var(--font-display);
  letter-spacing: 0.01em;
  color: #fff;
}
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1.5px solid var(--accent);
  box-shadow: inset 0 0 0 3px var(--ink), inset 0 0 0 4px var(--accent);
  color: var(--accent);
  font-weight: 700;
  font-family: var(--font-display);
  font-size: 14px;
  background: transparent;
}
.mainnav {
  display: flex;
  align-items: center;
  gap: 26px;
  font-size: 13.5px;
}
.mainnav a {
  color: #c3c9bd;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  transition: color 180ms ease;
}
.mainnav a:hover { color: #fff; }
.nav-cta {
  background: var(--accent);
  color: #fff !important;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-weight: 600;
  letter-spacing: 0.03em;
  transition: background 180ms ease;
}
.nav-cta:hover { background: var(--accent-dark); }

/* Layout */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 32px 24px 64px;
}
.container-narrow { max-width: 760px; }

.stats-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}
.stat-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-top: 3px solid var(--muted);
  position: relative;
}
.stat-open { border-top-color: var(--open); }
.stat-paid { border-top-color: var(--accent); }
.stat-label {
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--muted);
  font-weight: 600;
}
.stat-value {
  font-size: 32px;
  font-weight: 600;
  color: var(--ink);
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}
.stat-sub { font-size: 13px; color: var(--muted); }

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px 28px;
  box-shadow: 0 1px 0 var(--border-strong);
}
.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  gap: 12px;
  flex-wrap: wrap;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.panel-header h1 { font-size: 22px; margin: 0; color: var(--ink); font-weight: 600; }
.muted { color: var(--muted); margin: 2px 0 0; font-size: 14px; }

.filter-tabs {
  display: flex;
  gap: 2px;
  background: var(--bg);
  padding: 3px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.filter-tabs a {
  padding: 6px 14px;
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
  border-radius: 2px;
  color: var(--muted);
  transition: background 180ms ease, color 180ms ease;
}
.filter-tabs a.active {
  background: var(--ink);
  color: #fff;
}

/* Table — ruled like a ledger sheet */
.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
}
.table th {
  text-align: left;
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  font-weight: 600;
  padding: 10px 12px;
  border-bottom: 2px solid var(--ink);
}
.table td {
  padding: 13px 12px;
  border-bottom: 1px solid var(--border);
}
.table tbody tr:last-child td { border-bottom: none; }
.table tbody tr:hover td { background: var(--accent-soft); }
.table .num { text-align: right; }
.link { color: var(--accent-dark); font-weight: 600; font-family: var(--font-display); }
.link:hover { text-decoration: underline; }
.row-actions a {
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 700;
  color: var(--accent-dark);
  border: 1px solid var(--accent);
  padding: 4px 8px;
  border-radius: var(--radius);
  transition: background 180ms ease, color 180ms ease;
}
.row-actions a:hover { background: var(--accent); color: #fff; }
.text-danger { color: var(--danger); font-weight: 600; }

/* Badges — stamped labels, not pill-chips */
.badge {
  display: inline-block;
  padding: 3px 11px;
  border-radius: var(--radius);
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border: 1px solid transparent;
}
.badge-open { background: var(--open-soft); color: var(--open); border-color: color-mix(in srgb, var(--open) 35%, transparent); }
.badge-paid { background: var(--accent-soft); color: var(--accent-dark); border-color: color-mix(in srgb, var(--accent) 35%, transparent); }
.badge-overdue { background: var(--danger-soft); color: var(--danger); border-color: color-mix(in srgb, var(--danger) 35%, transparent); }
.badge-lg { font-size: 12.5px; padding: 6px 14px; }

/* Empty state */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  color: var(--muted);
}
.empty-state p { margin-bottom: 16px; font-family: var(--font-display); font-size: 16px; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 9px 18px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 180ms ease, border-color 180ms ease, transform 100ms ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.btn-secondary { background: var(--ink); color: #fff; }
.btn-secondary:hover { background: var(--ink-soft); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--border-strong); }
.btn-ghost:hover { background: var(--bg); }

/* Forms */
.form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 640px;
}
.form label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  flex: 1;
}
.form label.full { max-width: none; }
.form-row { display: flex; gap: 16px; }
.form input,
.form select,
.form textarea {
  font-size: 14px;
  padding: 9px 11px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  font-family: inherit;
  color: var(--text);
  background: #fff;
  transition: border-color 180ms ease, box-shadow 180ms ease;
}
.form label {
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 11.5px;
}
.form input:focus,
.form select:focus,
.form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.form-actions {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-top: 8px;
}
.alert {
  background: var(--danger-soft);
  color: var(--danger);
  padding: 10px 14px;
  border-radius: var(--radius);
  border-left: 3px solid var(--danger);
  font-size: 14px;
  margin-bottom: 16px;
}

/* Invoice form specific */
#invoice-form { max-width: none; }
.section-title {
  font-size: 16px;
  color: var(--ink);
  font-family: var(--font-display);
  margin: 12px 0 4px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}
.items-table th, .items-table td { padding: 8px; }
.items-table input {
  width: 100%;
  padding: 7px 9px;
}
.row-remove {
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 18px;
  cursor: pointer;
  line-height: 1;
}
.row-remove:hover { color: var(--danger); }

/* Invoice detail */
.invoice-detail .panel-header h1 {
  font-size: 26px;
  font-variant-numeric: tabular-nums;
}
.detail-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 4px 0 24px;
}
.detail-grid > div { display: flex; flex-direction: column; gap: 2px; }
.detail-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  font-weight: 700;
}
.totals-box {
  margin-top: 16px;
  margin-left: auto;
  max-width: 320px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.totals-box > div {
  display: flex;
  justify-content: space-between;
  font-size: 14px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.total-final {
  font-size: 19px;
  font-weight: 600;
  font-family: var(--font-display);
  color: var(--ink);
  border-top: 2px solid var(--ink);
  padding-top: 10px;
  margin-top: 4px;
}
.note-box {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}
.note-box p { margin: 6px 0 0; color: var(--text); }

/* The one bold move: a rubber-stamp seal for paid invoices */
.stamp {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 20px;
  border: 3px double var(--accent);
  border-radius: var(--radius);
  color: var(--accent);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  transform: rotate(-6deg);
  background: color-mix(in srgb, var(--accent) 6%, transparent);
  mix-blend-mode: multiply;
}
.stamp .stamp-date {
  display: block;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-weight: 600;
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: none;
  margin-top: 1px;
}
.stamp-wrap { display: flex; justify-content: flex-end; }

@media (max-width: 640px) {
  .form-row { flex-direction: column; }
  .detail-grid { grid-template-columns: 1fr; }
  .panel { padding: 18px; }
  .table { font-size: 13px; }
  .stat-value { font-size: 26px; }
  .mainnav { gap: 14px; }
}