:root {
  /* Light theme — warm, muted, professional */
  --bg: #f5f4ef;
  --surface: #ffffff;
  --surface-2: #faf9f5;
  --surface-3: #f0efe9;
  --text: #1f2937;
  --text-soft: #374151;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-bg: #eff6ff;
  --border: #e5e7eb;
  --border-strong: #d1d5db;
  --positive: #059669;
  --positive-bg: #ecfdf5;
  --negative: #dc2626;
  --warn: #b45309;
  --warn-bg: #fef3c7;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
  line-height: 1.5;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
}

#app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

.page-header {
  margin-bottom: 1.5rem;
}

.page-header h1 {
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 0.25rem;
  color: var(--text);
}

.page-header .sub {
  color: var(--muted);
  font-size: 0.88rem;
  margin: 0;
}

/* Controls */
.controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.ctrl-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.15rem;
}

.ctrl-group h3 {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin: 0 0 0.75rem;
}

.ctrl-row {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.ctrl-row label {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: var(--muted);
  flex: 1 1 auto;
  min-width: 130px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.input-wrap {
  display: flex;
  align-items: center;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  transition: border-color 0.15s;
}

.input-wrap:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-bg);
}

.input-wrap input {
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
  padding: 0.45rem 0.6rem;
  flex: 1;
  font-weight: 500;
  min-width: 0;
}

.input-wrap input:focus {
  outline: none;
}

.input-wrap .unit {
  font-size: 0.72rem;
  color: var(--muted);
  padding-right: 0.6rem;
  text-transform: none;
  letter-spacing: 0;
  white-space: nowrap;
}

.ctrl-group .note {
  margin: 0.7rem 0 0;
  padding: 0.5rem 0.7rem;
  border-radius: 5px;
  font-size: 0.78rem;
  line-height: 1.4;
  text-transform: none;
  letter-spacing: 0;
}

.ctrl-group .note.ok-note {
  background: var(--positive-bg);
  color: var(--positive);
}

.ctrl-group .note.warn-note {
  background: var(--warn-bg);
  color: var(--warn);
}

/* Offers */
.offers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.offer {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
}

.offer header {
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.title-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.75rem;
}

.offer h2 {
  font-size: 1.05rem;
  margin: 0;
  font-weight: 600;
  line-height: 1.3;
  color: var(--text);
}

.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  background: var(--accent-bg);
  color: var(--accent);
  border-radius: 4px;
  font-size: 0.72rem;
  font-weight: 500;
  white-space: nowrap;
  flex-shrink: 0;
}

.badge.warn {
  background: var(--warn-bg);
  color: var(--warn);
}

.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.55rem;
  margin-bottom: 1rem;
}

.stat {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.7rem 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.stat .label {
  color: var(--muted);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  line-height: 1.3;
}

.stat .value {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
  margin-top: 0.1rem;
}

.stat .detail {
  color: var(--muted);
  font-size: 0.7rem;
  font-variant-numeric: tabular-nums;
  line-height: 1.3;
}

table.breakdown {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

table.breakdown td {
  padding: 0.45rem 0;
  border-bottom: 1px solid var(--border);
}

table.breakdown td:last-child {
  text-align: right;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  font-weight: 500;
}

table.breakdown td:first-child {
  color: var(--text-soft);
  font-weight: normal;
}

table.breakdown tr.sep td {
  padding-top: 0.8rem;
}

table.breakdown tr.sub td {
  padding: 0 0 0.5rem 0;
  font-size: 0.75rem;
  border-bottom: 1px solid var(--border);
}

table.breakdown tr.sub td:first-child {
  color: var(--muted);
  font-style: italic;
}

table.breakdown tr.highlight td {
  color: var(--accent);
  font-weight: 600;
}

table.breakdown tr.highlight td:first-child {
  color: var(--accent);
}

table.breakdown tr:last-child td {
  border-bottom: none;
}

/* Notes collapsible */
details.notes {
  margin-top: 1rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.85rem;
}

details.notes summary {
  padding: 0.6rem 0.85rem;
  cursor: pointer;
  color: var(--accent);
  font-weight: 500;
  list-style: none;
  user-select: none;
}

details.notes summary::before {
  content: '▸';
  display: inline-block;
  margin-right: 0.5rem;
  transition: transform 0.15s;
}

details.notes[open] summary::before {
  transform: rotate(90deg);
}

details.notes summary::-webkit-details-marker {
  display: none;
}

.notes-body {
  padding: 0 0.85rem 0.75rem;
  color: var(--text-soft);
  line-height: 1.55;
}

.notes-body p {
  margin: 0 0 0.6rem;
}

.notes-body p:last-child {
  margin-bottom: 0;
}

.notes-body strong {
  color: var(--text);
}

/* Verdict */
.verdict-card {
  background: var(--accent-bg);
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 1.25rem;
}

.verdict-card h2 {
  font-size: 0.72rem;
  margin: 0 0 0.5rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.verdict-body {
  margin: 0;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
}

.verdict-body strong {
  font-size: 1.1rem;
  font-weight: 600;
}

.verdict-body .savings {
  color: var(--positive);
  font-weight: 500;
  font-size: 0.9rem;
}

@media (max-width: 720px) {
  .controls {
    grid-template-columns: 1fr;
  }
  .stat-grid {
    grid-template-columns: 1fr;
  }
  .stat .value { font-size: 1rem; }
}

/* Info panel */
.info-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.1rem 1.25rem;
  margin-bottom: 1.25rem;
}

.info-panel h3 {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin: 0 0 0.9rem;
}

.info-panel dl {
  margin: 0;
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 0.6rem 1.25rem;
}

.info-panel dt {
  color: var(--text);
  font-weight: 600;
  font-size: 0.88rem;
}

.info-panel dd {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.88rem;
  line-height: 1.5;
}

.info-panel dd strong {
  color: var(--text);
}

/* Stat grid responsive columns */
.stat-grid {
  display: grid;
  gap: 0.55rem;
  margin-bottom: 1rem;
}

.stat-grid.cols-3,
.stat-grid.cols-4 {
  grid-template-columns: 1fr 1fr;
}

.stat.accent {
  background: var(--accent-bg);
  border-color: var(--accent);
}

.stat.accent .label { color: var(--accent); }
.stat.accent .value { color: var(--accent); }

/* Risk section */
.risk-section {
  margin-top: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
}

.section-header {
  margin-bottom: 1rem;
}

.section-header h2 {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 0.2rem;
}

.section-header .sub {
  color: var(--muted);
  font-size: 0.88rem;
  margin: 0;
}

.risk-controls {
  margin-bottom: 1rem;
  max-width: 300px;
}

.risk-controls label {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.risk-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.risk-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
}

.risk-card h3 {
  font-size: 0.88rem;
  margin: 0 0 0.7rem;
  font-weight: 600;
}

.risk-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.risk-stat {
  padding: 0.55rem 0.6rem;
  border-radius: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.risk-stat.ok {
  background: var(--positive-bg);
  border-color: var(--positive);
}
.risk-stat.ok .rvalue { color: var(--positive); }

.risk-stat.warn {
  background: var(--warn-bg);
  border-color: var(--warn);
}
.risk-stat.warn .rvalue { color: var(--warn); }

.risk-stat.bad {
  background: #fee2e2;
  border-color: var(--negative);
}
.risk-stat.bad .rvalue { color: var(--negative); }

.rlabel {
  font-size: 0.68rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.risk-stat.ok .rlabel, .risk-stat.warn .rlabel, .risk-stat.bad .rlabel {
  color: inherit;
  opacity: 0.75;
}

.rvalue {
  font-size: 1rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.rdetail {
  font-size: 0.7rem;
  color: var(--muted);
}

.risk-stat.ok .rdetail, .risk-stat.warn .rdetail, .risk-stat.bad .rdetail {
  color: inherit;
  opacity: 0.75;
}

@media (max-width: 720px) {
  .info-panel dl {
    grid-template-columns: 1fr;
    gap: 0.3rem 0;
  }
  .info-panel dt {
    margin-top: 0.7rem;
  }
  .info-panel dt:first-child {
    margin-top: 0;
  }
  .risk-stats {
    grid-template-columns: 1fr;
  }
}

/* Prepayment slots */
.prepay-group {
  grid-column: 1 / -1;
}

.prepay-group .subtitle {
  font-weight: 400;
  font-size: 0.7rem;
  color: var(--muted);
  text-transform: none;
  letter-spacing: 0;
}

.prepay-slots {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.75rem;
  margin-bottom: 0.6rem;
}

.prepay-slot {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.7rem 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.slot-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.72rem;
}

.slot-num {
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.slot-warn {
  color: var(--warn);
  font-size: 0.7rem;
}

.prepay-slot label {
  display: grid;
  grid-template-columns: 60px 1fr;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* 4-column offer grid for 4 scenarios */
.offers {
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
}

/* Stats cols */
.stat-grid.cols-4 {
  grid-template-columns: repeat(2, 1fr);
}

/* Savings indicator inline in detail */
.savings-inline {
  color: var(--positive);
  font-weight: 600;
}

.stat.highlight-bg {
  background: var(--positive-bg);
  border-color: var(--positive);
}

.stat.highlight-bg .label {
  color: var(--positive);
}

/* Inline note in breakdown row */
.inline-note {
  font-size: 0.75rem;
  color: var(--muted);
  font-weight: 400;
  font-style: italic;
}

@media (max-width: 720px) {
  .prepay-slots {
    grid-template-columns: 1fr;
  }
  .prepay-slot label {
    grid-template-columns: 1fr;
  }
  .offers {
    grid-template-columns: 1fr;
  }
}

/* Target year calculator */
.target-section {
  margin-top: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
}

.target-controls {
  margin: 1rem 0 1.5rem;
  max-width: 500px;
}

.target-controls label {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.slider-wrap {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.75rem 1rem;
}

.slider-wrap input[type=range] {
  flex: 1;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border-strong);
  border-radius: 2px;
  outline: none;
}

.slider-wrap input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--surface);
  box-shadow: 0 1px 3px rgba(0,0,0,0.15);
}

.slider-wrap input[type=range]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--surface);
}

.slider-value {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  min-width: 3.5rem;
  text-align: right;
  text-transform: none;
  letter-spacing: 0;
}

.target-results {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.target-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
}

.target-card h4 {
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
  font-weight: 600;
}

.target-grid {
  display: grid;
  gap: 0.5rem;
}

.tstat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.6rem 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.tstat.primary {
  background: var(--accent-bg);
  border-color: var(--accent);
}

.tstat.primary .tvalue { color: var(--accent); }
.tstat.primary .tlabel { color: var(--accent); }

.tstat.saved {
  background: var(--positive-bg);
  border-color: var(--positive);
}

.tstat.saved .tvalue { color: var(--positive); }
.tstat.saved .tlabel { color: var(--positive); }

.tlabel {
  font-size: 0.68rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.tvalue {
  font-size: 1.05rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

.tdetail {
  font-size: 0.7rem;
  color: var(--muted);
}

.tstat.primary .tdetail, .tstat.saved .tdetail {
  color: inherit;
  opacity: 0.75;
}

/* --- Toggle groups (B in-principal / cash) --- */
.toggle-group {
  display: inline-flex;
  gap: 2px;
  padding: 2px;
  background: var(--surface-3);
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-top: 0.6rem;
}

.toggle-btn {
  background: transparent;
  border: none;
  padding: 0.35rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--muted);
  cursor: pointer;
  border-radius: 4px;
  transition: all 0.15s;
  font-family: inherit;
}

.toggle-btn:hover {
  color: var(--text);
}

.toggle-btn.active {
  background: var(--surface);
  color: var(--accent);
  box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}

/* Toggle in target card — smaller */
.tcard-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.tcard-header h4 {
  margin: 0;
}

.tcard-header .toggle-group {
  margin-top: 0;
}

.tcard-header .toggle-btn {
  padding: 0.25rem 0.55rem;
  font-size: 0.72rem;
}

/* Toggle in risk card */
.rcard-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.7rem;
}

.rcard-header h3 {
  margin: 0;
}

.rcard-header .toggle-group {
  margin-top: 0;
}

.rcard-header .toggle-btn {
  padding: 0.22rem 0.5rem;
  font-size: 0.7rem;
}

/* 3-column offer grid */
.offers {
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
}

/* Fix stat grid for 3-col when 3 stats */
.stat-grid.cols-3 {
  grid-template-columns: 1fr 1fr;
}
.stat-grid.cols-3 > .stat:last-child {
  grid-column: 1 / -1;
}

/* --- Mode toggle header --- */
.mode-toggle-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.mode-toggle-header h3 {
  margin: 0;
}

.mode-toggle .toggle-btn {
  padding: 0.45rem 0.85rem;
  font-size: 0.82rem;
}

/* --- 4-slot layout --- */
.prepay-group .prepay-slots {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

/* --- End mode section --- */
.end-mode-section {
  margin: 1rem 0 0.6rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--border);
}

.section-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.55rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.end-mode-toggle {
  display: flex;
  flex-wrap: wrap;
  margin-bottom: 0.6rem;
}

.end-mode-btn {
  font-size: 0.78rem;
  padding: 0.5rem 0.85rem;
}

.target-year-sub {
  margin-top: 0.7rem;
  padding: 0.8rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
}

.target-year-sub label {
  display: flex;
  gap: 0.6rem;
  align-items: center;
  font-size: 0.78rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
}

.target-year-sub .input-wrap {
  max-width: 140px;
}

.target-year-sub .note {
  margin: 0;
  font-size: 0.78rem;
  color: var(--muted);
}

/* --- Mode content container --- */
.mode-content {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* --- Periods table --- */
.periods {
  margin: 1rem 0 0.5rem;
  padding: 0.85rem 1rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.periods h4 {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--accent);
  margin: 0 0 0.6rem;
}

.periods-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.periods-table td {
  padding: 0.38rem 0;
  border-bottom: 1px solid var(--border);
}

.periods-table tr:last-child td {
  border-bottom: none;
}

.periods-table tr.balloon td {
  color: var(--accent);
  font-weight: 600;
  background: var(--accent-bg);
}

.periods-table tr.balloon td:first-child {
  border-radius: 4px 0 0 4px;
  padding-left: 0.5rem;
}
.periods-table tr.balloon td:last-child {
  border-radius: 0 4px 4px 0;
  padding-right: 0.5rem;
}

.period-monthly {
  text-align: right;
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  color: var(--text);
}

.period-count {
  text-align: right;
  color: var(--muted);
  font-size: 0.78rem;
  width: 5rem;
  padding-right: 0.25rem !important;
}

@media (max-width: 720px) {
  .mode-toggle-header {
    flex-direction: column;
    align-items: flex-start;
  }
  .mode-toggle, .end-mode-toggle {
    width: 100%;
  }
  .periods-table td:last-child {
    display: none;  /* hide count on mobile */
  }
}

/* Prepayment annotation in period breakdown */
.period-prepay-note {
  font-size: 0.72rem;
  color: var(--accent);
  margin-top: 0.2rem;
  font-weight: 500;
}

/* Stacked toggle (for longer labels like slider options) */
.toggle-group.stacked {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding: 3px;
}

.toggle-group.stacked .toggle-btn {
  text-align: left;
  padding: 0.55rem 0.85rem;
  font-size: 0.8rem;
  line-height: 1.3;
}

.toggle-group.stacked .toggle-btn + .toggle-btn {
  margin-top: 2px;
}

@media (min-width: 900px) {
  .toggle-group.stacked {
    flex-direction: row;
    flex-wrap: wrap;
  }
  .toggle-group.stacked .toggle-btn {
    flex: 1 1 auto;
    text-align: center;
    margin-top: 0;
    min-width: 200px;
  }
  .toggle-group.stacked .toggle-btn + .toggle-btn {
    margin-top: 0;
  }
}