:root {
  --iron: #1c1b19;
  --iron-2: #2a2825;
  --iron-3: #3a3733;
  --ash: #8e8880;
  --paper: #f4efe6;
  --paper-2: #e9e2d5;
  --ink: #1c1b19;
  --ember: #c4501f;
  --ember-hot: #e2692f;
  --line: rgba(28, 27, 25, 0.14);
  --serif: "Fraunces", Georgia, "Times New Roman", serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, Menlo, monospace;
  --max: 1120px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-underline-offset: 3px; }
a:hover { color: var(--ember); }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
  background: var(--iron);
  color: var(--paper);
  border-bottom: 1px solid var(--iron-3);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px; gap: 16px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font: 700 20px/1 var(--serif); letter-spacing: -0.01em; text-decoration: none;
}
.brand:hover { color: var(--paper); }
.brand-mark { width: 28px; height: 28px; flex: none; }
.nav { display: flex; gap: 22px; font-size: 14px; }
.nav a { text-decoration: none; color: #cfc8bc; }
.nav a:hover { color: var(--ember-hot); }

/* Hero */
.hero {
  background:
    radial-gradient(ellipse 60% 70% at 85% 110%, rgba(196, 80, 31, 0.35), transparent 70%),
    var(--iron);
  color: var(--paper);
  padding: 96px 0 104px;
}
.eyebrow {
  font: 500 12px/1 var(--mono); letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--ember-hot);
}
.hero h1 {
  font: 600 clamp(40px, 7vw, 76px)/1.02 var(--serif);
  letter-spacing: -0.025em; margin: 18px 0 24px; max-width: 14ch;
}
.hero p.lede { font-size: 20px; color: #d9d2c5; max-width: 54ch; margin: 0 0 36px; }

.signup { display: flex; gap: 10px; flex-wrap: wrap; max-width: 520px; }
.signup input[type="email"] {
  flex: 1 1 240px; min-width: 0;
  padding: 14px 16px; font: inherit; font-size: 16px;
  border: 1px solid var(--iron-3); border-radius: 4px;
  background: var(--iron-2); color: var(--paper);
}
.signup input[type="email"]::placeholder { color: var(--ash); }
.signup input[type="email"]:focus { outline: 2px solid var(--ember); outline-offset: 1px; }
.btn {
  padding: 14px 22px; font: 600 15px/1 var(--sans);
  border: 0; border-radius: 4px; cursor: pointer;
  background: var(--ember); color: #fff;
}
.btn:hover { background: var(--ember-hot); }
.btn:disabled { opacity: 0.6; cursor: default; }
.signup-note { font-size: 13px; color: var(--ash); margin-top: 12px; min-height: 1.4em; }
.signup-note.ok { color: #9fd49a; }
.signup-note.err { color: #f29a7a; }
.hp { position: absolute; left: -9999px; }

/* Sections */
section { padding: 88px 0; }
.section-head { max-width: 680px; margin-bottom: 48px; }
.section-head h2 {
  font: 600 clamp(30px, 4vw, 42px)/1.1 var(--serif); letter-spacing: -0.02em; margin: 12px 0 14px;
}
.section-head p { color: #4d4943; margin: 0; }
.eyebrow.dark { color: var(--ember); }

.pillars {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 2px solid var(--ink);
}
.pillar { padding: 28px 24px 8px 0; border-right: 1px solid var(--line); }
.pillar + .pillar { padding-left: 24px; }
.pillar:last-child { border-right: 0; }
.pillar .num { font: 500 13px/1 var(--mono); color: var(--ember); }
.pillar h3 { font: 600 22px/1.2 var(--serif); margin: 14px 0 10px; }
.pillar p { font-size: 15px; color: #4d4943; margin: 0 0 14px; }
.pillar ul { margin: 0; padding: 0; list-style: none; font-size: 14px; }
.pillar li { padding: 7px 0; border-top: 1px dashed var(--line); }

/* Calculator */
.calc-section { background: var(--paper-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.calc {
  display: grid; grid-template-columns: 1fr 1.15fr; gap: 0;
  background: var(--paper); border: 1px solid var(--line); border-radius: 6px; overflow: hidden;
}
.calc-inputs { padding: 32px; border-right: 1px solid var(--line); }
.calc-out { padding: 32px; background: var(--iron); color: var(--paper); }
.field { margin-bottom: 26px; }
.field label { display: block; font-weight: 600; font-size: 14px; margin-bottom: 10px; }
.seg { display: flex; flex-wrap: wrap; gap: 6px; }
.seg button {
  font: 500 14px/1 var(--sans); padding: 10px 14px; border-radius: 4px; cursor: pointer;
  border: 1px solid var(--line); background: transparent; color: var(--ink);
}
.seg button[aria-pressed="true"] { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.range-row { display: flex; align-items: center; gap: 14px; }
.range-row input[type="range"] { flex: 1; accent-color: var(--ember); }
.range-row output { font: 600 22px/1 var(--mono); min-width: 2ch; text-align: right; }
.calc-out .label { font: 500 12px/1 var(--mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ash); }
.calc-out .big { font: 600 clamp(34px, 5vw, 52px)/1.05 var(--serif); margin: 12px 0 6px; letter-spacing: -0.02em; }
.calc-out .sub { color: #cfc8bc; margin: 0 0 24px; }
.calc-out dl { display: grid; grid-template-columns: auto 1fr; gap: 10px 18px; margin: 0 0 24px; font-size: 15px; }
.calc-out dt { color: var(--ash); }
.calc-out dd { margin: 0; }
.calc-out .fine { font-size: 13px; color: var(--ash); border-top: 1px solid var(--iron-3); padding-top: 14px; margin: 0; }

/* Principles */
.principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.principle h3 { font: 600 20px/1.25 var(--serif); margin: 0 0 10px; }
.principle p { margin: 0; color: #4d4943; font-size: 15px; }
.principle .rule { width: 32px; height: 3px; background: var(--ember); margin-bottom: 18px; }

/* Newsletter band */
.band { background: var(--iron); color: var(--paper); }
.band .wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.band h2 { font: 600 clamp(28px, 4vw, 40px)/1.1 var(--serif); margin: 12px 0 12px; letter-spacing: -0.02em; }
.band p { color: #cfc8bc; margin: 0; }
.band ol { margin: 0; padding: 0; list-style: none; counter-reset: n; }
.band ol li { counter-increment: n; padding: 14px 0; border-top: 1px solid var(--iron-3); display: flex; gap: 14px; }
.band ol li::before { content: "0" counter(n); font: 500 13px/1.8 var(--mono); color: var(--ember-hot); }

/* Prose pages */
.page-hero { background: var(--iron); color: var(--paper); padding: 72px 0 64px; }
.page-hero h1 { font: 600 clamp(36px, 6vw, 58px)/1.05 var(--serif); letter-spacing: -0.02em; margin: 14px 0 14px; max-width: 18ch; }
.page-hero p { color: #d9d2c5; font-size: 19px; max-width: 58ch; margin: 0; }
.prose { max-width: 720px; padding: 64px 0 96px; }
.prose h2 { font: 600 28px/1.2 var(--serif); margin: 48px 0 12px; letter-spacing: -0.01em; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font: 600 19px/1.3 var(--sans); margin: 28px 0 8px; }
.prose p, .prose li { color: #35322e; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin: 6px 0; }
.prose table { width: 100%; border-collapse: collapse; font-size: 15px; margin: 18px 0; }
.prose th, .prose td { text-align: left; padding: 10px 12px 10px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.prose th { font: 600 12px/1.3 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: #6b665e; }
.callout { border-left: 3px solid var(--ember); background: var(--paper-2); padding: 16px 20px; margin: 24px 0; }
.updated { font: 500 13px/1 var(--mono); color: #6b665e; }

/* Footer */
.site-footer { background: #141311; color: var(--ash); padding: 48px 0; font-size: 14px; }
.site-footer .wrap { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.site-footer a { color: #cfc8bc; text-decoration: none; margin-right: 20px; }
.site-footer a:hover { color: var(--ember-hot); }
.site-footer .tag { font-family: var(--serif); color: #cfc8bc; font-size: 16px; }

@media (max-width: 900px) {
  .pillars { grid-template-columns: 1fr 1fr; }
  .pillar:nth-child(2) { border-right: 0; }
  .pillar:nth-child(3) { padding-left: 0; }
  .pillar:nth-child(n+3) { border-top: 1px solid var(--line); }
  .calc { grid-template-columns: 1fr; }
  .calc-inputs { border-right: 0; border-bottom: 1px solid var(--line); }
  .principles { grid-template-columns: 1fr; gap: 32px; }
  .band .wrap { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .wrap { padding: 0 16px; }
  .nav { gap: 14px; font-size: 13px; }
  .nav .hide-sm { display: none; }
  .hero { padding: 64px 0 72px; }
  section { padding: 64px 0; }
  .pillars { grid-template-columns: 1fr; }
  .pillar, .pillar + .pillar { padding: 24px 0 8px; border-right: 0; border-top: 1px solid var(--line); }
  .pillar:first-child { border-top: 0; }
  .calc-inputs, .calc-out { padding: 24px 20px; }
}