:root {
  /* Monochrome Background */
  --bg: #f5f5f5;
  --bg-elevated: #ffffff;
  --card-bg: #ffffff;
  --card-bg-hover: #fafafa;

  /* Text Colors */
  --text: #000000;
  --text-muted: #666666;
  --text-dim: #999999;
  --text-emphasis: #000000;

  /* Borders - sharp and minimal */
  --border: #000000;
  --border-light: #e0e0e0;
  --border-focus: #000000;

  /* Status Colors - minimal palette */
  --green: #16a34a;
  --green-bg: #f0fdf4;
  --red: #dc2626;
  --red-bg: #fef2f2;

  /* Chart Colors */
  --bar-2025: #000000;
  --bar-2028: #666666;
  --chart-grid: #e0e0e0;
  --chart-axis: #666666;

  /* No shadows - flat design */
  --shadow: none;

  /* Layout */
  --radius: 2px;
  --max-width: 100%;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* Better touch interactions on mobile */
@media (hover: none) and (pointer: coarse) {
  .box-summary {
    padding: 0.5rem 0;
  }

  .assumptions summary {
    padding: 0.75rem;
  }

  input[type="number"],
  input[type="range"],
  input[type="checkbox"] {
    min-height: 44px; /* iOS minimum touch target */
  }

  .card input[type="number"] {
    font-size: 16px; /* Prevents iOS zoom on focus */
  }
}

body {
  font-family: "SF Mono", "Courier New", monospace;
  background: var(--bg);
  color: var(--text);
  line-height: 1.4;
  letter-spacing: 0;
  min-height: 100vh;
  margin: 0;
  padding: 0;
  overflow-x: hidden;
}

header {
  background: var(--bg);
  border-bottom: 2px solid var(--border);
  color: var(--text);
  padding: 1rem;
  text-align: left;
}

header h1 {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  margin: 0;
}

.share-btn {
  background: var(--bg);
  border: 2px solid var(--border);
  color: var(--text);
  padding: 0.5rem 1rem;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  cursor: pointer;
  font-family: "SF Mono", monospace;
  border-radius: var(--radius);
  transition: all 0.2s;
}

.share-btn:hover {
  background: var(--text);
  color: var(--bg);
}

.share-btn:active {
  transform: scale(0.95);
}

.share-btn.copied {
  background: var(--green);
  color: white;
  border-color: var(--green);
}

.subtitle {
  font-size: 0.7rem;
  margin-top: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  opacity: 0.7;
  word-wrap: break-word;
}

.creator-link {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: all 0.2s;
}

.creator-link:hover {
  color: var(--text);
  border-bottom-color: var(--text);
}

main {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1rem;
  padding: 1rem;
  height: calc(100vh - 120px);
  overflow: hidden;
}

/* Input Section */
.input-section {
  grid-column: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* Cards */
.cards {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.card {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem;
}

.card h2 {
  font-size: 0.75rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hint {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.65rem;
  text-transform: none;
}

.card label {
  display: block;
  font-size: 0.75rem;
  font-weight: 400;
  margin-bottom: 0.5rem;
  color: var(--text);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.card input[type="number"] {
  display: block;
  width: 100%;
  margin-top: 0.25rem;
  padding: 0.5rem;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-family: "SF Mono", monospace;
}

.card input[type="number"]:focus {
  outline: none;
  border-color: var(--border);
  background: var(--bg-elevated);
}

.checkbox-label {
  display: flex !important;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  accent-color: var(--border);
  cursor: pointer;
}

/* Tooltip */
.tooltip {
  color: var(--text-muted);
  cursor: help;
  position: relative;
  font-weight: 400;
}

.tooltip:hover::after {
  content: attr(data-tip);
  position: absolute;
  left: 50%;
  bottom: 100%;
  transform: translateX(-50%);
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius);
  font-size: 0.7rem;
  white-space: nowrap;
  max-width: 260px;
  white-space: normal;
  z-index: 10;
  pointer-events: none;
  line-height: 1.4;
  font-family: "SF Mono", monospace;
}

/* Assumptions */
.assumptions {
  margin-top: 0.5rem;
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
}

.assumptions summary {
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  font-weight: 700;
  font-size: 0.75rem;
  user-select: none;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.assumptions summary:hover {
  color: var(--accent);
}

.assumptions-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.5rem;
  padding: 0 0.75rem 0.75rem;
}

.assumptions-grid label {
  font-size: 0.7rem;
  font-weight: 400;
  text-transform: uppercase;
}

.assumptions-grid input[type="number"] {
  display: block;
  width: 100%;
  margin-top: 0.25rem;
  padding: 0.35rem 0.5rem;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius);
  font-size: 0.75rem;
  font-family: "SF Mono", monospace;
}

.assumptions-grid input[type="number"]:focus {
  outline: none;
  border-color: var(--border);
  background: var(--bg-elevated);
}

/* Results */
.results-section {
  grid-column: 2;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto 1fr;
  gap: 0.5rem;
  overflow-y: auto;
}

.results-section > h2 {
  display: none;
}

/* Difference banner */
.difference-banner {
  padding: 0.75rem;
  border-radius: var(--radius);
  font-weight: 700;
  text-align: center;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border: 2px solid var(--border);
  grid-column: 1 / -1;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.difference-banner.savings {
  background: var(--green-bg);
  color: var(--green);
  border-color: var(--green);
}

.difference-banner.costs-more {
  background: var(--red-bg);
  color: var(--red);
  border-color: var(--red);
}

.difference-banner.neutral {
  background: var(--bg);
  color: var(--text);
  border-color: var(--border);
}

/* Comparison grid */
.comparison-grid {
  grid-column: 1;
  grid-row: 2 / 4;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.column {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem;
}

.column h3 {
  font-size: 0.75rem;
  margin-bottom: 0.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.result-body h4 {
  font-size: 0.75rem;
  margin-top: 0.5rem;
  margin-bottom: 0.35rem;
  color: var(--text);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-family: "SF Mono", monospace;
}

.result-body .line {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  padding: 0.1rem 0;
  font-family: "SF Mono", monospace;
}

.result-body .line.indent {
  padding-left: 1rem;
  color: var(--text-muted);
  font-size: 0.7rem;
}

.result-body .line.total {
  font-weight: 700;
  border-top: 1px solid var(--border);
  margin-top: 0.35rem;
  padding-top: 0.35rem;
  font-size: 0.75rem;
}

.result-body .line.grand-total {
  font-weight: 700;
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  margin-top: 0.5rem;
  padding: 0.5rem;
  font-size: 0.75rem;
  color: var(--text);
  font-family: "SF Mono", monospace;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.result-body .line.net-income {
  background: var(--green-bg);
  border-color: var(--green);
  color: var(--green);
}

/* Box details collapsible */
.box-details {
  margin: 0.35rem 0;
}

.box-summary {
  cursor: pointer;
  user-select: none;
  list-style: none;
  font-size: 0.75rem;
  padding: 0.2rem 0;
  color: var(--text-muted);
  font-family: "SF Mono", monospace;
  font-weight: 400;
}

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

.box-summary:hover {
  color: var(--text);
}

.box-details-content {
  margin-top: 0.35rem;
  padding-left: 0;
}

.box-details-content .line {
  font-size: 0.75rem;
}

.box-details[open] .box-summary {
  color: var(--text);
}

/* Bar chart */
.chart-section {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem;
}

.chart-section:first-of-type {
  grid-column: 2;
  grid-row: 2;
}

#projectionSection {
  grid-column: 2;
  grid-row: 3;
}

.chart-section h3 {
  font-size: 0.75rem;
  margin-bottom: 0.5rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.chart-row {
  margin-bottom: 0.5rem;
}

.chart-row-label {
  font-size: 0.7rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.bar-pair {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.bar-wrapper {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.bar-year {
  font-size: 0.65rem;
  min-width: 2.5rem;
  text-align: right;
  color: var(--text);
  font-family: "SF Mono", monospace;
}

.bar {
  height: 0.875rem;
  border-radius: var(--radius);
  min-width: 2px;
  position: relative;
}

.bar.bar-2025 {
  background: var(--bar-2025);
}

.bar.bar-2028 {
  background: var(--bar-2028);
}

.bar-value {
  font-size: 0.65rem;
  white-space: nowrap;
  color: var(--text);
  font-family: "SF Mono", monospace;
}

/* Legend */
.chart-legend {
  display: flex;
  gap: 1rem;
  margin-top: 0.5rem;
  font-size: 0.7rem;
  color: var(--text);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  font-family: "SF Mono", monospace;
}

.legend-swatch {
  width: 10px;
  height: 10px;
  border-radius: var(--radius);
  display: inline-block;
}

.legend-swatch.c2025 { background: var(--bar-2025); }
.legend-swatch.c2028 { background: var(--bar-2028); }

/* Projection chart */
.projection-controls {
  margin-bottom: 0.5rem;
}

.projection-controls label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.projection-controls input[type="range"] {
  flex: 1;
  max-width: 200px;
  accent-color: var(--border);
  cursor: pointer;
}

#projectionYearsLabel {
  font-weight: 700;
  min-width: 4rem;
  font-family: "SF Mono", monospace;
}

.canvas-container {
  position: relative;
  width: 100%;
  aspect-ratio: 2.5 / 1;
  max-height: 220px;
}

#projectionCanvas {
  width: 100%;
  height: 100%;
  display: block;
}

.projection-tooltip {
  display: none;
  position: absolute;
  pointer-events: none;
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.4rem 0.5rem;
  border-radius: var(--radius);
  font-size: 0.7rem;
  line-height: 1.4;
  white-space: nowrap;
  z-index: 20;
  font-family: "SF Mono", monospace;
}

.projection-summary {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.5rem;
  flex-wrap: wrap;
}

.summary-card {
  flex: 1;
  min-width: 100px;
  padding: 0.4rem 0.5rem;
  border-radius: var(--radius);
  font-size: 0.7rem;
  text-align: center;
  border: 1px solid var(--border);
}

.summary-card .summary-label {
  font-weight: 700;
  margin-bottom: 0.15rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.summary-card .summary-value {
  font-weight: 700;
  font-size: 0.8rem;
  font-family: "SF Mono", monospace;
}

.summary-card.no-tax {
  background: var(--bg);
  border-color: var(--border-light);
  color: var(--text-muted);
}

.summary-card.system-2025 {
  background: var(--bg);
  border-color: var(--border);
  color: var(--text);
}

.summary-card.system-2028 {
  background: var(--bg);
  border-color: var(--border);
  color: var(--text);
}

.projection-empty {
  text-align: center;
  color: var(--text-muted);
  padding: 1rem 0;
  font-size: 0.7rem;
}

/* Footer */
footer {
  padding: 0.75rem 1rem;
  border-top: 2px solid var(--border);
  background: var(--bg);
}

.disclaimer {
  font-size: 0.65rem;
  color: var(--text-muted);
  line-height: 1.4;
  font-style: normal;
}

/* Responsive */
@media (max-width: 1400px) {
  main {
    grid-template-columns: 1fr;
    height: auto;
  }

  .input-section {
    grid-column: 1;
  }

  .results-section {
    grid-column: 1;
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto auto;
  }

  .difference-banner {
    grid-column: 1;
  }

  .comparison-grid {
    grid-column: 1;
    grid-row: 2;
    flex-direction: row;
    gap: 0.5rem;
  }

  .comparison-grid .column {
    flex: 1;
  }

  .chart-section:first-of-type {
    grid-column: 1;
    grid-row: 3;
  }

  #projectionSection {
    grid-column: 1;
    grid-row: 4;
  }
}

@media (max-width: 768px) {
  body {
    font-size: 0.875rem;
  }

  header {
    padding: 0.75rem;
  }

  header h1 {
    font-size: 0.875rem;
  }

  .subtitle {
    font-size: 0.65rem;
  }

  .share-btn {
    font-size: 0.65rem;
    padding: 0.4rem 0.75rem;
  }

  main {
    padding: 0.5rem;
    gap: 0.5rem;
  }

  .comparison-grid {
    flex-direction: column;
  }

  .card {
    padding: 0.5rem;
  }

  .card h2 {
    font-size: 0.7rem;
    margin-bottom: 0.5rem;
  }

  .card label {
    font-size: 0.7rem;
    margin-bottom: 0.35rem;
  }

  .card input[type="number"] {
    padding: 0.4rem;
    font-size: 0.8rem;
  }

  .assumptions summary {
    padding: 0.4rem 0.5rem;
    font-size: 0.7rem;
  }

  .assumptions-grid {
    padding: 0 0.5rem 0.5rem;
  }

  .difference-banner {
    padding: 0.5rem;
    font-size: 0.7rem;
  }

  .column {
    padding: 0.5rem;
  }

  .column h3 {
    font-size: 0.7rem;
  }

  .result-body h4 {
    font-size: 0.7rem;
    margin-top: 0.4rem;
    margin-bottom: 0.25rem;
  }

  .result-body .line {
    font-size: 0.7rem;
    padding: 0.08rem 0;
    gap: 0.25rem;
  }

  .result-body .line span:first-child {
    flex: 1;
    min-width: 0;
    word-break: break-word;
  }

  .result-body .line span:last-child {
    flex-shrink: 0;
    text-align: right;
  }

  .result-body .line.indent {
    font-size: 0.65rem;
    padding-left: 0.75rem;
  }

  .result-body .line.total {
    font-size: 0.7rem;
    margin-top: 0.25rem;
    padding-top: 0.25rem;
  }

  .result-body .line.grand-total {
    font-size: 0.7rem;
    padding: 0.4rem;
    margin-top: 0.4rem;
  }

  .box-summary {
    font-size: 0.7rem;
    padding: 0.15rem 0;
  }

  .box-details-content .line {
    font-size: 0.7rem;
  }

  .chart-section {
    padding: 0.5rem;
  }

  .chart-section h3 {
    font-size: 0.7rem;
    margin-bottom: 0.4rem;
    padding-bottom: 0.4rem;
  }

  .chart-row {
    margin-bottom: 0.4rem;
  }

  .chart-row-label {
    font-size: 0.65rem;
    margin-bottom: 0.2rem;
  }

  .bar-wrapper {
    gap: 0.25rem;
  }

  .bar-year {
    font-size: 0.6rem;
    min-width: 2rem;
  }

  .bar {
    height: 0.75rem;
  }

  .bar-value {
    font-size: 0.6rem;
  }

  .chart-legend {
    font-size: 0.65rem;
    margin-top: 0.4rem;
    gap: 0.75rem;
  }

  .legend-swatch {
    width: 8px;
    height: 8px;
  }

  .projection-controls label {
    font-size: 0.65rem;
    gap: 0.4rem;
  }

  .projection-controls input[type="range"] {
    max-width: 150px;
  }

  #projectionYearsLabel {
    font-size: 0.65rem;
    min-width: 3.5rem;
  }

  .canvas-container {
    aspect-ratio: 1.5 / 1;
    max-height: 180px;
  }

  .projection-summary {
    flex-direction: column;
    gap: 0.4rem;
  }

  .summary-card {
    padding: 0.35rem 0.4rem;
    font-size: 0.65rem;
    min-width: auto;
  }

  .summary-card .summary-value {
    font-size: 0.7rem;
  }

  .projection-tooltip {
    font-size: 0.65rem;
    padding: 0.3rem 0.4rem;
  }

  .tooltip:hover::after {
    left: 0;
    transform: none;
    max-width: 200px;
    font-size: 0.65rem;
  }

  footer {
    padding: 0.5rem;
  }

  .disclaimer {
    font-size: 0.6rem;
  }
}

@media (max-width: 480px) {
  header h1 {
    font-size: 0.8rem;
  }

  .subtitle {
    font-size: 0.6rem;
  }

  main {
    padding: 0.4rem;
  }

  .card {
    padding: 0.4rem;
  }

  .card h2 {
    font-size: 0.65rem;
  }

  .card label {
    font-size: 0.65rem;
  }

  .difference-banner {
    font-size: 0.65rem;
    padding: 0.4rem;
  }

  .result-body h4 {
    font-size: 0.65rem;
  }

  .result-body .line {
    font-size: 0.65rem;
  }

  .result-body .line.indent {
    font-size: 0.6rem;
  }

  .result-body .line.grand-total {
    font-size: 0.65rem;
    padding: 0.35rem;
  }

  .chart-section h3 {
    font-size: 0.65rem;
  }

  .bar-year,
  .bar-value {
    font-size: 0.55rem;
  }

  .canvas-container {
    max-height: 150px;
  }
}