:root {
  --ink: #10251e;
  --muted: #607168;
  --line: #d8e2dc;
  --paper: #f6f8f4;
  --panel: #ffffff;
  --green: #146c43;
  --mint: #b9f2cf;
  --lime: #e8ff9a;
  --warn: #f4b942;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; }
a { color: inherit; }
button, textarea, select, input { font: inherit; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px clamp(20px, 5vw, 72px);
  border-bottom: 1px solid rgba(216, 226, 220, .9);
  background: rgba(246, 248, 244, .94);
  backdrop-filter: blur(14px);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 9px; color: white; background: var(--green); font-weight: 800; }
nav { display: flex; gap: 24px; }
nav a { color: var(--muted); text-decoration: none; font-size: .9rem; }
nav a:hover { color: var(--ink); }

main { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
.hero { display: grid; grid-template-columns: 1.5fr .8fr; gap: clamp(36px, 7vw, 92px); padding: clamp(72px, 11vw, 140px) 0 86px; align-items: end; }
.eyebrow { margin: 0 0 14px; color: var(--green); text-transform: uppercase; letter-spacing: .13em; font-size: .72rem; font-weight: 800; }
h1 { max-width: 850px; margin: 0; font-size: clamp(3rem, 7vw, 6.6rem); letter-spacing: -.065em; line-height: .93; }
.lede { max-width: 760px; margin: 28px 0 0; color: var(--muted); font-size: clamp(1.08rem, 2vw, 1.35rem); line-height: 1.6; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.button { display: inline-flex; justify-content: center; align-items: center; border: 1px solid var(--ink); border-radius: 999px; padding: 12px 18px; text-decoration: none; cursor: pointer; transition: transform .16s ease, background .16s ease; }
.button:hover { transform: translateY(-1px); }
.button.primary { border-color: var(--green); color: white; background: var(--green); }
.button.secondary { color: var(--ink); background: transparent; }
.button:disabled { cursor: not-allowed; opacity: .45; transform: none; }
.button.wide { width: 100%; border-radius: 10px; }
.principle-card { border: 1px solid var(--line); border-radius: 24px; padding: 28px; background: var(--panel); box-shadow: 0 20px 70px rgba(16, 37, 30, .08); }
.principle-card ol { display: grid; gap: 20px; margin: 0; padding: 0; list-style: none; }
.principle-card li { display: grid; grid-template-columns: 34px 1fr; gap: 10px; align-items: start; line-height: 1.45; }
.principle-card li span { color: var(--green); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

.workspace { padding: 80px 0; border-top: 1px solid var(--line); }
.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 24px; margin-bottom: 28px; }
.section-heading h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.4rem); letter-spacing: -.045em; }
.section-heading > p { max-width: 420px; margin: 0; color: var(--muted); text-align: right; }
.workspace-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 20px; }
.panel { min-height: 440px; border: 1px solid var(--line); border-radius: 22px; padding: clamp(22px, 4vw, 36px); background: var(--panel); }
.controls { display: grid; gap: 22px; align-content: start; }
label { display: grid; gap: 9px; font-weight: 700; font-size: .88rem; }
textarea, select { width: 100%; border: 1px solid var(--line); border-radius: 10px; color: var(--ink); background: #fbfcfa; padding: 12px; outline: none; }
textarea:focus, select:focus, input:focus { border-color: var(--green); box-shadow: 0 0 0 3px rgba(20, 108, 67, .12); }
.field-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.range-row { display: grid; grid-template-columns: 1fr 96px; gap: 12px; align-items: center; }
input[type="range"] { accent-color: var(--green); }
output { color: var(--muted); font-weight: 500; text-align: right; }
.result.empty { display: grid; place-items: center; }
.empty-state { max-width: 340px; text-align: center; }
.empty-state h3 { margin: 18px 0 8px; font-size: 1.5rem; }
.empty-state p { margin: 0; color: var(--muted); }
.signal { display: block; width: 82px; height: 5px; margin: auto; border-radius: 99px; background: var(--mint); box-shadow: 0 0 0 9px rgba(185, 242, 207, .25); }
.result-content { display: grid; gap: 24px; }
.route-head { display: flex; justify-content: space-between; align-items: start; gap: 18px; }
.route-head h3 { margin: 4px 0 0; font-size: 2rem; letter-spacing: -.04em; }
.badge { border-radius: 999px; padding: 7px 10px; color: var(--green); background: var(--mint); font-size: .72rem; font-weight: 800; text-transform: uppercase; }
.metric-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.metric { border: 1px solid var(--line); border-radius: 14px; padding: 15px; background: #fbfcfa; }
.metric strong { display: block; margin-top: 8px; font-size: 1.2rem; }
.metric span { color: var(--muted); font-size: .76rem; }
.reason-list { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; }
.reason-list li { display: grid; grid-template-columns: 18px 1fr; gap: 10px; color: var(--muted); line-height: 1.45; }
.reason-list li::before { content: "✓"; color: var(--green); font-weight: 900; }
.uncertainty { border-left: 3px solid var(--warn); padding: 12px 14px; color: var(--muted); background: #fff9ea; font-size: .88rem; line-height: 1.5; }

.method, .audit-section { padding: 80px 0; border-top: 1px solid var(--line); }
.method-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.method-grid article { border: 1px solid var(--line); border-radius: 18px; padding: 22px; background: var(--panel); }
.method-grid article > span { color: var(--green); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.method-grid h3 { margin: 30px 0 10px; }
.method-grid p { margin: 0; color: var(--muted); line-height: 1.55; }
.audit-list { display: grid; gap: 10px; }
.audit-empty { color: var(--muted); }
.audit-item { display: grid; grid-template-columns: 150px 1fr auto; gap: 16px; align-items: center; border: 1px solid var(--line); border-radius: 14px; padding: 16px; background: var(--panel); }
.audit-item code { color: var(--muted); }
.audit-item strong { font-size: .95rem; }
.audit-item span { color: var(--green); font-size: .85rem; font-weight: 700; }

footer { display: flex; justify-content: space-between; gap: 20px; width: min(1180px, calc(100% - 40px)); margin: 0 auto; padding: 34px 0 48px; border-top: 1px solid var(--line); color: var(--muted); font-size: .82rem; }

@media (max-width: 820px) {
  nav { display: none; }
  .hero, .workspace-grid { grid-template-columns: 1fr; }
  .principle-card { max-width: 620px; }
  .method-grid { grid-template-columns: 1fr 1fr; }
  .section-heading { align-items: start; flex-direction: column; }
  .section-heading > p { text-align: left; }
}

@media (max-width: 520px) {
  main { width: min(100% - 24px, 1180px); }
  .topbar { padding: 12px; }
  h1 { font-size: 3.25rem; }
  .field-grid, .metric-grid, .method-grid { grid-template-columns: 1fr; }
  .audit-item { grid-template-columns: 1fr; gap: 6px; }
  footer { flex-direction: column; width: calc(100% - 24px); }
}