:root {
  color-scheme: light dark;
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #1b1f24;
  --muted: #5b6470;
  --border: #dde1e6;
  --accent: #0b6bcb;
  --healthy: #1a7f4b;
  --healthy-bg: #e6f4ec;
  --thin: #8a5a00;
  --thin-bg: #fdf3dc;
  --loss: #b3261e;
  --loss-bg: #fbe9e7;
  --radius: 10px;
  font-family:
    "Inter",
    system-ui,
    -apple-system,
    "Segoe UI",
    sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12151a;
    --panel: #1b2027;
    --text: #e8ebef;
    --muted: #9aa4b1;
    --border: #2d343e;
    --accent: #5aa9f5;
    --healthy: #5cd08f;
    --healthy-bg: #173326;
    --thin: #f0c060;
    --thin-bg: #352a12;
    --loss: #f28b82;
    --loss-bg: #3b1b19;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

h1,
h2 {
  line-height: 1.25;
}

h2 {
  font-size: 1.05rem;
  margin: 0 0 0.5rem;
}

.page-header,
.layout,
.page-footer {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 16px;
}

.page-header {
  padding-top: 2rem;
}

.page-header h1 {
  margin: 0 0 0.25rem;
  font-size: 1.75rem;
}

.page-header p {
  margin: 0;
  color: var(--muted);
}

.layout {
  display: grid;
  grid-template-columns: minmax(280px, 360px) 1fr;
  gap: 20px;
  align-items: start;
  margin-top: 1.5rem;
}

@media (max-width: 820px) {
  .layout {
    grid-template-columns: 1fr;
  }
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
}

form.panel {
  position: sticky;
  top: 16px;
}

@media (max-width: 820px) {
  form.panel {
    position: static;
  }
}

.results {
  display: grid;
  gap: 16px;
  min-width: 0;
}

.hint {
  color: var(--muted);
  font-size: 0.85rem;
  margin: 0.15rem 0 0;
}

.examples {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: 0.9rem;
}

button {
  font: inherit;
  font-size: 0.85rem;
  padding: 5px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
}

button:hover {
  border-color: var(--accent);
}

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

.field {
  display: block;
  margin-top: 14px;
}

.label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 4px;
}

.input-wrap {
  position: relative;
  display: block;
}

.input-wrap input {
  width: 100%;
  font: inherit;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
}

.input-wrap.prefix input {
  padding-left: 24px;
}

.input-wrap.suffix input {
  padding-right: 28px;
}

.input-wrap.prefix::before,
.input-wrap.suffix::after {
  content: attr(data-unit);
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

.input-wrap.prefix::before {
  left: 10px;
}

.input-wrap.suffix::after {
  right: 10px;
}

input[aria-invalid="true"] {
  border-color: var(--loss);
}

.helper {
  margin-top: 14px;
  border-top: 1px solid var(--border);
  padding-top: 10px;
}

.helper summary {
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--accent);
}

.helper-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.helper > button {
  margin-top: 10px;
}

.errors {
  color: var(--loss);
  font-size: 0.9rem;
  padding-left: 1.1rem;
  margin: 12px 0 0;
}

.errors:empty {
  display: none;
}

.verdict {
  border-radius: var(--radius);
  padding: 18px 20px;
  display: flex;
  align-items: center;
  gap: 20px;
  border: 1px solid var(--border);
  background: var(--panel);
}

.verdict p {
  margin: 0;
  font-size: 1.05rem;
}

.verdict.healthy {
  background: var(--healthy-bg);
  border-color: var(--healthy);
}

.verdict.thin {
  background: var(--thin-bg);
  border-color: var(--thin);
}

.verdict.loss {
  background: var(--loss-bg);
  border-color: var(--loss);
}

.ratio {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 96px;
}

#ratio {
  white-space: nowrap;
  font-size: 2.2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.ratio-label {
  font-size: 0.8rem;
  color: var(--muted);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.card-label {
  font-size: 0.8rem;
  color: var(--muted);
}

.card-value {
  font-size: 1.4rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.card-note {
  font-size: 0.8rem;
  color: var(--muted);
}

.chart svg {
  width: 100%;
  height: auto;
  display: block;
  margin-top: 8px;
}

.chart .axis,
.chart .grid {
  stroke: var(--border);
}

.chart text {
  fill: var(--muted);
  font-size: 11px;
}

.chart .curve {
  fill: none;
  stroke: var(--accent);
  stroke-width: 2.5;
}

.chart .cac-line {
  stroke: var(--loss);
  stroke-dasharray: 5 4;
  stroke-width: 1.5;
}

.chart .ltv-line {
  stroke: var(--healthy);
  stroke-dasharray: 2 4;
  stroke-width: 1.5;
}

.chart .payback-dot {
  fill: var(--accent);
}

.chart .label-strong {
  fill: var(--text);
  font-weight: 600;
}

.levers {
  margin: 0;
  padding-left: 1.1rem;
}

.levers li + li {
  margin-top: 4px;
}

.table-wrap {
  overflow-x: auto;
}

table {
  border-collapse: separate;
  border-spacing: 3px;
  font-variant-numeric: tabular-nums;
  font-size: 0.9rem;
  margin-top: 6px;
}

th {
  font-weight: 600;
  color: var(--muted);
  padding: 4px 8px;
  text-align: center;
  white-space: nowrap;
}

td {
  text-align: center;
  padding: 6px 10px;
  border-radius: 4px;
  min-width: 64px;
}

td.healthy {
  background: var(--healthy-bg);
  color: var(--healthy);
}

td.thin {
  background: var(--thin-bg);
  color: var(--thin);
}

td.loss {
  background: var(--loss-bg);
  color: var(--loss);
}

td.current {
  outline: 2px solid var(--text);
  font-weight: 700;
}

.method summary {
  cursor: pointer;
  list-style: none;
}

.method summary h2 {
  display: inline;
}

.method summary::before {
  content: "▸ ";
  color: var(--muted);
}

.method[open] summary::before {
  content: "▾ ";
}

.method li + li {
  margin-top: 6px;
}

.page-footer {
  color: var(--muted);
  font-size: 0.85rem;
  padding-top: 2rem;
  padding-bottom: 2rem;
}

.page-footer a {
  color: var(--accent);
}