:root {
  --bg: #fbfbf8; --card: #ffffff; --ink: #1c2027; --muted: #5d6472; --line: #e6e5df;
  --brand: #2f6b57; --brand-ink: #ffffff; --brand-soft: #e7f0ec; --warn: #9a5b13;
  color-scheme: light dark;
  font-family: 'Geist', ui-sans-serif, system-ui, -apple-system, 'Segoe UI', sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.6; font-size: 17px;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #121417; --card: #1a1d22; --ink: #ecebe7; --muted: #a3a9b5; --line: #2b2f37;
    --brand: #86c9b1; --brand-ink: #0f2a21; --brand-soft: #1c302a; --warn: #e7b26b; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); }
a { color: var(--brand); }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 20px; }
.narrow { max-width: 760px; }

.nav { display: flex; align-items: center; justify-content: space-between; padding: 18px 0; gap: 12px; flex-wrap: wrap; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--ink); text-decoration: none; }
.logo span { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 8px; background: var(--brand); color: var(--brand-ink); }
.nav nav { display: flex; gap: 18px; flex-wrap: wrap; font-size: .95rem; }
.nav nav a { color: var(--muted); text-decoration: none; }
.nav nav a:hover { color: var(--ink); }

.btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: 9px; font-weight: 600; text-decoration: none; border: 1px solid var(--line); color: var(--ink); background: var(--card); }
.btn.primary { background: var(--brand); color: var(--brand-ink); border-color: var(--brand); }
.btn:hover { filter: brightness(1.05); }

.hero { padding: 56px 0 40px; }
.eyebrow { text-transform: uppercase; letter-spacing: .12em; font-size: .78rem; color: var(--brand); font-weight: 600; margin: 0 0 10px; }
h1 { font-size: clamp(2rem, 4.5vw, 3.1rem); line-height: 1.12; letter-spacing: -.02em; margin: 0 0 18px; }
h2 { font-size: clamp(1.4rem, 2.6vw, 1.9rem); letter-spacing: -.01em; line-height: 1.2; margin: 48px 0 14px; }
h3 { font-size: 1.1rem; margin: 0 0 6px; }
.lead { font-size: 1.2rem; color: var(--muted); max-width: 680px; margin: 0 0 26px; }
.actions { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.small { font-size: .88rem; color: var(--muted); }

.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 20px 22px; }
.card p { margin: 0; color: var(--muted); font-size: .97rem; }
.steps { counter-reset: s; }
.steps .card h3::before { counter-increment: s; content: counter(s); display: inline-grid; place-items: center; width: 26px; height: 26px; margin-right: 8px; border-radius: 50%; background: var(--brand-soft); color: var(--brand); font-size: .85rem; }

table { width: 100%; border-collapse: collapse; font-size: .95rem; background: var(--card); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
th, td { padding: 10px 14px; border-bottom: 1px solid var(--line); text-align: left; }
th { font-size: .78rem; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
@media (max-width: 640px) {
  table { display: block; overflow-x: auto; font-size: .88rem; }
  th, td { padding: 8px 10px; }
  .card { padding: 16px; }
  .cta { padding: 24px 18px; }
}
tfoot td { font-weight: 700; border-bottom: 0; }
.formula { font-family: ui-monospace, 'Cascadia Code', monospace; background: var(--brand-soft); padding: 14px 16px; border-radius: 10px; font-size: .95rem; overflow-x: auto; }
.note { border-left: 3px solid var(--warn); padding: 4px 14px; color: var(--muted); }

details { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px 18px; margin-bottom: 10px; }
summary { font-weight: 600; cursor: pointer; }
details p { color: var(--muted); margin: 10px 0 0; }

.cta { margin: 56px 0; padding: 32px; border-radius: 14px; background: var(--brand-soft); text-align: center; }
.cta h2 { margin-top: 0; }
.cta p { color: var(--muted); }

.calc { display: grid; gap: 12px; }
.calc label { display: flex; flex-direction: column; gap: 4px; font-size: .9rem; color: var(--muted); }
.calc input { font: inherit; padding: 9px 12px; border-radius: 8px; border: 1px solid var(--line); background: var(--bg); color: var(--ink); }
.calc .row { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); }
.calc output { font-size: 1.8rem; font-weight: 700; color: var(--brand); }

footer { border-top: 1px solid var(--line); margin-top: 64px; padding: 28px 0 40px; color: var(--muted); font-size: .9rem; }
footer .links { display: flex; gap: 18px; flex-wrap: wrap; margin-bottom: 10px; }
footer a { color: var(--muted); }