:root {
  --color-bg: #F2F0E6;
  --color-surface: #FFFFFF;
  --color-ink: #1F2A24;
  --color-ink-soft: #55645C;
  --color-line: #DEDACB;
  --color-line-strong: #C7C2AE;
  --color-accent: #B87A22;
  --color-accent-dark: #8C5C17;
  --color-accent-soft: #F0DDB6;
  --color-dusk-start: #1B2E35;
  --color-dusk-mid: #4A6B52;
  --color-dusk-end: #A9C99B;
  --color-negative: #E8291A;
  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
  --radius: 6px;
  --shadow-card: 0 1px 2px rgba(27, 30, 20, 0.06), 0 8px 24px -12px rgba(27, 30, 20, 0.18);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-body);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ---------- HERO ---------- */
.hero-logo {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: #FBF7EE;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 24px;
  margin-bottom: 16px;
}

.hero-logo-mark {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(180deg, var(--color-dusk-start), var(--color-dusk-end));
  border: 1px solid var(--color-accent-soft);
  display: inline-block;
  flex-shrink: 0;
}

.hero {
  position: relative;
  background: linear-gradient(115deg, var(--color-dusk-start) 0%, var(--color-dusk-mid) 55%, var(--color-dusk-end) 100%);
  color: #FBF7EE;
  padding: 30px 32px 40px;
  overflow: hidden;
}

.hero-inner {
  max-width: 780px;
  margin: 0 auto;
}

.eyebrow {
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12px;
  color: var(--color-accent-soft);
  margin: 0 0 14px;
}

.hero h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(28px, 4.5vw, 44px);
  margin: 0 0 14px;
  letter-spacing: -0.01em;
}

.subhead {
  font-size: 16px;
  color: #E8E2D2;
  max-width: 56ch;
  margin: 0;
}

.horizon-line {
  height: 3px;
  width: 100%;
  margin-top: 40px;
  background: linear-gradient(90deg, rgba(169,201,155,0) 0%, var(--color-dusk-end) 45%, var(--color-accent-soft) 55%, rgba(169,201,155,0) 100%);
}

/* ---------- NAV ---------- */
.section-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-line-strong);
  padding: 10px 24px;
}

.section-nav a {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.03em;
  text-decoration: none;
  color: var(--color-ink-soft);
  padding: 8px 12px;
  border-radius: var(--radius);
  transition: background 0.15s ease, color 0.15s ease;
}

.section-nav a:hover,
.section-nav a:focus-visible {
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
}

/* ---------- LAYOUT ---------- */
main {
  max-width: 920px;
  margin: 0 auto;
  padding: 8px 24px 24px;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: 10px;
  box-shadow: var(--shadow-card);
  padding: 32px 32px 36px;
  margin-bottom: 28px;
  scroll-margin-top: 64px;
}

.disclaimer-card {
  padding: 18px 24px;
  border-left: 4px solid var(--color-accent);
  background: #FBF3E2;
}

.disclaimer-card p {
  margin: 0;
  font-size: 14px;
  color: var(--color-ink);
  line-height: 1.5;
}

.warning-banner {
  margin: 4px 0 20px;
  padding: 14px 18px;
  border-left: 4px solid var(--color-negative);
  background: #FBE4E0;
  color: var(--color-ink);
  font-size: 13.5px;
  font-weight: 600;
  line-height: 1.5;
  border-radius: 6px;
}

.card-head {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  margin-bottom: 26px;
  padding-bottom: 18px;
  border-bottom: 2px solid var(--color-accent-soft);
}

.card-head .num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-accent);
  border: 1px solid var(--color-accent-soft);
  background: #FBF3E2;
  border-radius: 999px;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
}

.card-head h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 26px;
  margin: 0 0 4px;
}

.card-desc {
  margin: 0;
  font-size: 14px;
  color: var(--color-ink-soft);
}

/* ---------- FIELDS ---------- */
.field-grid {
  display: grid;
  gap: 20px;
  margin-bottom: 20px;
}

.field-grid:last-child { margin-bottom: 0; }
.field-grid.two-col { grid-template-columns: repeat(2, 1fr); }
.field-grid.three-col { grid-template-columns: repeat(3, 1fr); }

@media (max-width: 640px) {
  .field-grid.two-col,
  .field-grid.three-col { grid-template-columns: 1fr; }
}

.card > .field { margin-bottom: 20px; }

.field label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13.5px;
  font-weight: 600;
  margin-bottom: 7px;
  color: var(--color-ink);
}

.field-letter {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  color: var(--color-accent-dark);
  background: var(--color-accent-soft);
  padding: 1px 8px;
  border-radius: 999px;
  white-space: nowrap;
}

.field label .field-letter {
  margin-left: auto;
}

.field-formula {
  border-radius: var(--radius);
}

/* ---------- LEDGER (Capital Gain calculations) ---------- */
.ledger {
  margin-bottom: 8px;
}

.ledger-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 0;
}

.ledger-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--color-ink);
}

.ledger-value {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--color-ink-soft);
  white-space: nowrap;
}

.ledger-row-total {
  border: 1px solid var(--color-line-strong);
  border-radius: var(--radius);
  background: #F3F1E9;
  padding: 14px 16px;
}

.ledger-row-total .ledger-label {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-ink);
}

.ledger-row-total .ledger-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-ink);
}

.field input[type="text"],
.field input[type="number"],
.field input[type="date"],
.field select,
.data-table input,
.data-table select,
.readonly-display {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 14px;
  padding: 9px 11px;
  border: 1px solid var(--color-line-strong);
  border-radius: var(--radius);
  background: #FDFCF8;
  color: var(--color-ink);
  text-align: right;
}

.readonly-display {
  background: #F3F1E9;
  color: var(--color-ink-soft);
}

.field input:focus,
.field select:focus,
.data-table input:focus,
.data-table select:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
  border-color: var(--color-accent);
}

.field input:required:invalid {
  border-color: var(--color-negative);
}

.field-checkbox {
  display: flex;
  align-items: center;
  gap: 10px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
}

.checkbox-label input {
  width: 17px;
  height: 17px;
  accent-color: var(--color-accent);
}

/* ---------- INFO ICON / POPUP ---------- */
.info-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 1px solid var(--color-accent);
  background: transparent;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
}

.info-icon:hover,
.info-icon:focus-visible {
  background: var(--color-accent);
  color: #FFF;
}

.popup-overlay {
  position: fixed;
  inset: 0;
  background: rgba(27, 33, 26, 0.45);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 20px;
}

.popup-overlay[hidden] { display: none; }

.popup-box {
  background: var(--color-surface);
  max-width: 420px;
  width: 100%;
  border-radius: 10px;
  padding: 24px;
  box-shadow: 0 20px 50px -12px rgba(0,0,0,0.35);
  border-top: 4px solid var(--color-accent);
}

.popup-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  margin: 0 0 10px;
  color: var(--color-ink);
}

.popup-title:empty { display: none; }

.popup-text {
  font-size: 14.5px;
  color: var(--color-ink);
  margin: 0 0 18px;
  line-height: 1.5;
}

/* ---------- TABLES ---------- */
.table-label {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  margin: 8px 0 12px;
}

.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--color-line);
  border-radius: 8px;
  margin-bottom: 20px;
}

.data-table {
  border-collapse: collapse;
  width: 100%;
  min-width: 560px;
  font-size: 13.5px;
}

.data-table thead th {
  text-align: right;
  padding: 10px 12px;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-accent-dark);
  background: #FBF3E2;
  border-bottom: 1px solid var(--color-line-strong);
  white-space: nowrap;
}

.data-table thead th:first-child { text-align: left; }

.data-table td {
  padding: 7px 10px;
  border-bottom: 1px solid var(--color-line);
  white-space: nowrap;
  text-align: right;
}

.data-table td:first-child { text-align: left; }

.data-table tbody tr:nth-child(odd) { background: #FCFBF7; }

.cmp-row-total td {
  font-weight: 700;
  font-size: 15px;
  border-top: 2px solid var(--color-line-strong);
  color: var(--color-ink);
}

.data-table td.readonly {
  font-family: var(--font-mono);
  color: var(--color-ink-soft);
  background: #F3F1E9;
}

.data-table input {
  min-width: 88px;
}

.data-table tfoot td {
  border-top: 2px solid var(--color-line-strong);
  border-bottom: none;
  background: #FBF3E2;
  font-family: var(--font-mono);
}

/* ---------- BUTTONS ---------- */
.actions-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 8px;
  padding-top: 24px;
  border-top: 1px solid var(--color-line);
}

.actions-note {
  margin: 10px 0 0;
  font-size: 12px;
  color: var(--color-ink-soft);
}

.btn {
  font-family: var(--font-body);
  font-size: 13.5px;
  font-weight: 600;
  padding: 11px 20px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.15s ease;
}

.btn:active { transform: translateY(1px); }

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

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

.btn-secondary {
  background: transparent;
  color: var(--color-ink);
  border-color: var(--color-line-strong);
}

.btn-secondary:hover { background: var(--color-accent-soft); }

/* ---------- SUDOKU GRID ---------- */
.sudoku-wrap {
  display: flex;
  justify-content: center;
  margin: 8px 0 24px;
}

.sudoku-grid {
  display: grid;
  grid-template-columns: repeat(9, clamp(30px, 8.2vw, 50px));
  grid-template-rows: repeat(9, clamp(30px, 8.2vw, 50px));
  border: 3px solid var(--color-ink);
  border-radius: 4px;
  overflow: hidden;
  background: var(--color-line);
}

.sudoku-cell {
  width: 100%;
  height: 100%;
  border: 1px solid var(--color-line-strong);
  background: var(--color-surface);
  text-align: center;
  font-family: var(--font-mono);
  font-size: clamp(15px, 4vw, 20px);
  font-weight: 700;
  color: var(--color-ink);
  padding: 0;
  -moz-appearance: textfield;
}

.sudoku-cell::-webkit-outer-spin-button,
.sudoku-cell::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.sudoku-cell:focus {
  outline: none;
  background: var(--color-accent-soft);
  position: relative;
  z-index: 1;
}

.sudoku-cell.box-right { border-right: 3px solid var(--color-ink); }
.sudoku-cell.box-bottom { border-bottom: 3px solid var(--color-ink); }

.sudoku-cell.given {
  background: #F3F1E9;
  color: var(--color-ink);
  cursor: default;
}

.sudoku-cell.solved-value {
  color: var(--color-accent-dark);
  font-weight: 600;
  background: #FBF3E2;
}

.sudoku-cell.hint-highlight {
  background: var(--color-accent-soft) !important;
  box-shadow: inset 0 0 0 2px var(--color-accent);
  animation: sudoku-pulse 1.1s ease-in-out infinite;
}

@keyframes sudoku-pulse {
  0%, 100% { box-shadow: inset 0 0 0 2px var(--color-accent); }
  50% { box-shadow: inset 0 0 0 2px var(--color-accent-dark); }
}

.sudoku-cell.error-cell {
  background: #FBE4E0 !important;
  color: var(--color-negative);
}

.sudoku-message {
  min-height: 20px;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--color-ink-soft);
  text-align: center;
  margin-bottom: 8px;
  padding: 0 12px;
}

.sudoku-message.msg-success {
  color: #2F6B3A;
  font-weight: 600;
}

.sudoku-message.msg-error {
  color: var(--color-negative);
  font-weight: 600;
}

@media (max-width: 480px) {
  .actions-row { flex-direction: column; }
  .actions-row .btn { width: 100%; }
}

.btn-kofi {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #FF5E5B;
  color: #FFFFFF;
  text-decoration: none;
}

.btn-kofi:hover { background: #E5504D; }

/* ---------- AD SLOTS ---------- */
.sponsor-panel-wrap {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 24px;
}

.sponsor-panel-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 90px;
  border: 1px dashed var(--color-line-strong);
  border-radius: 8px;
  background: #FBF9F3;
  color: var(--color-ink-soft);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin: 24px 0;
}

/* ---------- SUPPORT / TIP JAR ---------- */
.support-card {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 24px 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  text-align: center;
}

.support-text {
  font-size: 13.5px;
  color: var(--color-ink-soft);
  margin: 0;
}

/* ---------- FULL DISCLAIMER SECTION ---------- */
.disclaimer-section {
  max-width: 920px;
  margin: 24px auto 0;
  padding: 24px;
  border-top: 1px solid var(--color-line);
}

.disclaimer-section h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 20px;
  margin: 0 0 12px;
  color: var(--color-ink);
}

.disclaimer-section p {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--color-ink-soft);
  margin: 0 0 10px;
}

.disclaimer-section p:last-child { margin-bottom: 0; }

/* ---------- FOOTER ---------- */
.page-footer {
  max-width: 920px;
  margin: 0 auto;
  padding: 8px 24px 48px;
  color: var(--color-ink-soft);
  font-size: 12.5px;
}

.page-footer p { margin: 0 0 6px; }

/* ---------- PRINT ---------- */
@media print {
  .sponsor-panel-wrap, .support-card, .actions-row, .popup-overlay, .section-nav { display: none !important; }
  .card { box-shadow: none; break-inside: avoid; }
  body { background: #fff; }
}