:root {
  --bg: #f4f4f5;
  --sheet: #ffffff;
  --ink: #1c1c1e;
  --ink-soft: #55555c;
  --ink-faint: #9a9aa2;
  --line: #e6e6ea;
  --line-strong: #d3d3da;
  --accent: #2f6f4f;
  --accent-soft: #eef5f0;
  --radius: 10px;
  --sheet-w: 820px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
}

/* ---------- App bar ---------- */
.app-bar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: rgba(244, 244, 245, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.app-bar__brand { display: flex; align-items: center; gap: 9px; font-weight: 600; }
.app-bar__mark { color: var(--accent); font-size: 20px; }
.app-bar__name { letter-spacing: -0.01em; }
.app-bar__actions { display: flex; gap: 12px; flex-wrap: wrap; justify-content: flex-end; }
.btn-group { display: flex; gap: 8px; flex-wrap: wrap; }
.btn-group + .btn-group { padding-left: 12px; border-left: 1px solid var(--line); }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%) translateY(8px);
  z-index: 50;
  max-width: 90vw;
  background: var(--ink);
  color: #fff;
  font-size: 14px;
  padding: 10px 16px;
  border-radius: 8px;
  opacity: 0;
  transition: opacity 0.2s, transform 0.2s;
  pointer-events: none;
}
.toast.is-visible { opacity: 1; transform: translateX(-50%) translateY(0); }

.app-note {
  max-width: var(--sheet-w);
  margin: 16px auto 0;
  padding: 0 24px;
  color: var(--ink-faint);
  font-size: 13px;
  text-align: center;
}

/* ---------- Buttons ---------- */
.btn {
  font: inherit;
  font-size: 14px;
  font-weight: 500;
  border-radius: 8px;
  padding: 8px 16px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { background: #275c42; }
.btn--ghost { background: transparent; color: var(--ink-soft); border-color: var(--line-strong); }
.btn--ghost:hover { background: #fff; color: var(--ink); }
.btn--add { margin-top: 10px; width: 100%; border-style: dashed; }

/* ---------- Sheet ---------- */
.sheet {
  max-width: var(--sheet-w);
  margin: 20px auto 64px;
  background: var(--sheet);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 48px 56px;
}

/* ---------- Editable fields ---------- */
.editable, input, textarea, select {
  font-family: inherit;
  color: var(--ink);
}
input, textarea, select {
  border: 1px solid transparent;
  border-radius: 6px;
  padding: 5px 7px;
  background: transparent;
  transition: border-color 0.12s, background 0.12s;
  font-size: 15px;
}
input:hover, textarea:hover, select:hover { border-color: var(--line); }
input:focus, textarea:focus, select:focus,
.editable:focus {
  outline: none;
  border-color: var(--accent);
  background: var(--accent-soft);
}
textarea { resize: vertical; }
.editable { border-radius: 6px; padding: 2px 4px; }
.editable:hover { background: var(--accent-soft); }

/* ---------- Invoice header ---------- */
.inv-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
}
.inv-title {
  font-size: 34px;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--accent);
}
.inv-head__meta { display: grid; gap: 4px; min-width: 240px; }
.meta-row {
  display: grid;
  grid-template-columns: 80px 1fr;
  align-items: center;
  gap: 8px;
}
.meta-label { color: var(--ink-faint); font-size: 13px; text-align: right; }
.meta-input { font-size: 14px; text-align: right; }

.rule { border: none; border-top: 1px solid var(--line); margin: 24px 0; }

/* ---------- Parties ---------- */
.inv-parties {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  margin-bottom: 32px;
}
.party { display: flex; flex-direction: column; gap: 4px; }
.party-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--ink-faint);
  margin-bottom: 2px;
}
.party-name { font-weight: 600; font-size: 16px; }
.party-details { color: var(--ink-soft); font-size: 14px; line-height: 1.5; }
.party-extra { display: flex; flex-direction: column; gap: 2px; margin-top: 2px; }
.party-line { color: var(--ink-soft); font-size: 13px; }

/* ---------- Items table ---------- */
.items { width: 100%; border-collapse: collapse; }
.items thead th {
  text-align: left;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
  font-weight: 600;
  padding: 0 8px 8px;
  border-bottom: 1.5px solid var(--line-strong);
}
.col-qty, .col-rate, .col-disc, .col-amount { text-align: right; }
.col-qty { width: 64px; }
.col-rate { width: 96px; }
.col-disc { width: 72px; }
.col-amount { width: 110px; }
.col-remove { width: 32px; }
.cell-disc input { text-align: right; }

.items tbody td {
  padding: 4px 4px;
  border-bottom: 1px solid var(--line);
  vertical-align: middle;
}
.items tbody input { width: 100%; }
.cell-desc input { text-align: left; }
.cell-qty input, .cell-rate input { text-align: right; }
.cell-amount { text-align: right; font-variant-numeric: tabular-nums; color: var(--ink); padding-right: 8px; }

.row-remove {
  border: none;
  background: transparent;
  color: var(--ink-faint);
  cursor: pointer;
  font-size: 18px;
  line-height: 1;
  padding: 4px 6px;
  border-radius: 6px;
}
.row-remove:hover { background: #fbeaea; color: #c0392b; }

/* ---------- Footer ---------- */
.inv-footer {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 32px;
  margin-top: 28px;
}
.inv-notes { display: flex; flex-direction: column; gap: 4px; }
.notes-input { color: var(--ink-soft); font-size: 14px; }

.inv-totals { display: flex; flex-direction: column; gap: 6px; }
.total-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 14px;
  color: var(--ink-soft);
  padding: 2px 0;
}
.total-val { font-variant-numeric: tabular-nums; color: var(--ink); }
.total-row--grand {
  margin-top: 6px;
  padding-top: 12px;
  border-top: 1.5px solid var(--line-strong);
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
}
.total-row--grand .total-val { color: var(--accent); }
.tax-label { display: inline-flex; align-items: center; gap: 4px; }
.tax-input { width: 56px; text-align: right; }
.unit-input { font-size: 12px; }
.currency-input { font-size: 13px; }
.total-currency { color: var(--ink-faint); font-size: 13px; }

/* ---------- Payment details ---------- */
.inv-payment {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}
.payment-head { display: flex; align-items: baseline; gap: 10px; margin-bottom: 12px; }
.payment-hint { color: var(--ink-faint); font-size: 12px; }
.payment-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 32px;
}
.pay-field { display: grid; grid-template-columns: 150px 1fr; align-items: center; gap: 8px; }
.pay-label { color: var(--ink-faint); font-size: 13px; }
.pay-input { font-size: 14px; width: 100%; }
.ocr-wrap { display: flex; align-items: center; gap: 8px; }
.ocr-wrap .pay-input { flex: 1; }
.ocr-hint { font-size: 12px; white-space: nowrap; }
.ocr-hint.is-valid { color: var(--accent); }
.ocr-hint.is-invalid { color: #c0392b; }

/* Hidden optional fields (empty) in print/export */
.is-empty { display: none !important; }

/* ---------- Print ---------- */
@media print {
  :root { --bg: #fff; }
  .no-print { display: none !important; }
  html, body { background: #fff; }
  .sheet {
    margin: 0;
    border: none;
    border-radius: 0;
    max-width: none;
    padding: 0;
  }
  input, textarea, select {
    border-color: transparent !important;
    background: transparent !important;
  }
  .col-remove { display: none; }
  .col-disc { width: auto; }
  .inv-payment { break-inside: avoid; }
  @page { margin: 18mm; }
}

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .sheet { padding: 28px 22px; margin: 12px; }
  .inv-head { flex-direction: column; }
  .inv-head__meta { min-width: 0; width: 100%; }
  .inv-parties, .inv-footer { grid-template-columns: 1fr; }
  .payment-grid { grid-template-columns: 1fr; }
  .pay-field { grid-template-columns: 1fr; gap: 2px; }
  .meta-input, .inv-title { text-align: left; }
  .meta-label { text-align: left; }
}