/* Ledger paper, deep-forest ink — a business-case document, not a fintech app. */

:root {
  --bg: #eaeee0;
  --paper: #f7f8f0;
  --ink: #1c2b21;
  --ink-muted: #5c6b5e;
  --rule: #c7d0bd;
  --rule-strong: #1c2b21;
  --forest: #1b4d3e;
  --forest-soft: #dde6d9;
  --gold: #8a6a22;
  --gold-soft: #efe6cf;
  --shadow: 0 18px 40px rgba(20, 32, 24, 0.1);

  --font-display: "Fraunces", "Iowan Old Style", ui-serif, Georgia, serif;
  --font-sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101d17;
    --paper: #17271f;
    --ink: #edf0e5;
    --ink-muted: #a3b3a3;
    --rule: #33473b;
    --rule-strong: #edf0e5;
    --forest: #7fb59a;
    --forest-soft: #1f3a2e;
    --gold: #e0bb63;
    --gold-soft: #2c2517;
    --shadow: 0 18px 44px rgba(0, 0, 0, 0.45);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  min-height: 100vh;
  padding: 48px 20px 64px;
}

.wrap {
  max-width: 920px;
  margin: 0 auto;
}

.header {
  text-align: center;
  margin-bottom: 32px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12px;
  font-weight: 600;
  color: var(--gold);
  margin: 0 0 10px;
}

.header h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 40px;
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}

.sub {
  color: var(--ink-muted);
  font-size: 15px;
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.5;
}

.ledger {
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 4px;
  box-shadow: var(--shadow);
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
}

@media (max-width: 760px) {
  .ledger {
    grid-template-columns: 1fr;
  }
}

.ledger-heading {
  margin: 0 0 20px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--ink-muted);
  border-bottom: 1px solid var(--rule);
  padding-bottom: 12px;
}

.ledger-inputs {
  padding: 32px 30px;
  border-right: 1px solid var(--rule);
}

@media (max-width: 760px) {
  .ledger-inputs {
    border-right: none;
    border-bottom: 1px solid var(--rule);
  }
}

.field {
  padding: 16px 0;
  border-bottom: 1px dashed var(--rule);
}

.field:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.field-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 10px;
}

.field label {
  font-weight: 600;
  font-size: 13.5px;
  color: var(--ink);
}

.field .unit {
  font-size: 11px;
  color: var(--ink-muted);
  white-space: nowrap;
}

.field input[type="number"] {
  width: 100%;
  padding: 9px 10px;
  font-family: var(--font-mono);
  font-size: 16px;
  font-variant-numeric: tabular-nums;
  border: 1px solid var(--rule);
  border-radius: 2px;
  margin-bottom: 10px;
  background: var(--bg);
  color: var(--ink);
}

.field input[type="number"]:focus {
  outline: 2px solid var(--forest);
  outline-offset: 1px;
}

.field input[type="range"] {
  width: 100%;
  accent-color: var(--forest);
}

.ledger-result {
  padding: 32px 30px;
  display: flex;
  flex-direction: column;
}

.hero-metric {
  text-align: center;
  padding: 22px 12px 26px;
  margin-bottom: 22px;
  background: var(--gold-soft);
  border: 1px solid var(--rule);
  border-radius: 4px;
}

.hero-label {
  margin: 0 0 8px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--ink-muted);
}

.hero-value {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 64px;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--gold);
  letter-spacing: -0.02em;
}

.sub-metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.metric {
  background: var(--forest-soft);
  border-radius: 4px;
  padding: 16px 18px;
}

.metric-label {
  margin: 0 0 6px;
  font-size: 11px;
  font-weight: 600;
  color: var(--ink-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.metric-value {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 26px;
  font-variant-numeric: tabular-nums;
  color: var(--forest);
  letter-spacing: -0.01em;
}

.footer-note {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--rule);
  font-size: 13px;
  color: var(--ink-muted);
  line-height: 1.5;
}

.page-footer {
  text-align: center;
  margin-top: 30px;
  font-size: 13px;
  color: var(--ink-muted);
}

.page-footer a {
  color: var(--forest);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.page-footer a:hover {
  opacity: 0.8;
}