/* ==========================================================================
   Should I Build This? — SaaS Opportunity Kill Test
   Design system: founder due-diligence memo.
   Palette: archival paper, ink, auditor blue, oxblood (KILL), ledger green (BUILD).
   Type: Libre Caslon Text (display) · Public Sans (body) · IBM Plex Mono (data).
   ========================================================================== */

:root {
  --paper: #f4f2ec;
  --sheet: #fdfcf8;
  --ink: #1a1e22;
  --ink-soft: #4c525a;
  --ink-faint: #63686e; /* 4.9:1 on --paper; keep ≥4.5:1 (WCAG AA small text) */
  --hairline: #d9d4c7;
  --hairline-dark: #b9b3a2;
  --ledger: #1f4e79;
  --ledger-soft: #e8eef4;
  --kill: #8c1d18;
  --kill-soft: #f6e9e8;
  --build: #1e6b45;
  --build-soft: #e7f0eb;
  --caution: #6e5417; /* ≥4.5:1 on --caution-soft (WCAG AA at chip size) */
  --caution-soft: #f5efdd;
  --unknown: #5b5f66;
  --unknown-soft: #ececea;

  --font-display: "Libre Caslon Text", "Iowan Old Style", Georgia, serif;
  --font-body: "Public Sans", -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  --w-page: 1120px;
  --w-memo: 780px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---- base text ---- */

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 0.6em;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(2.1rem, 4.6vw, 3.4rem); }
h2 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); }
h3 { font-size: 1.2rem; }

p { margin: 0 0 1em; }
p.lede { font-size: 1.2rem; color: var(--ink-soft); line-height: 1.6; }

a { color: var(--ledger); text-underline-offset: 3px; }
a:hover { color: var(--ink); }

:focus-visible {
  outline: 2px solid var(--ledger);
  outline-offset: 3px;
  border-radius: 1px;
}

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: var(--sheet);
  padding: 0.5rem 1rem; z-index: 100; font-family: var(--font-mono); font-size: 0.8rem;
}
.skip-link:focus { left: 0; }

/* ---- utility type ---- */

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--ledger);
  margin: 0 0 1rem;
}

.mono { font-family: var(--font-mono); }

/* ---- classification bar ---- */

.classification {
  background: var(--ink);
  color: #e8e4d8;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-align: center;
  padding: 0.45rem 1rem;
}
.classification strong { color: #f2b8b5; font-weight: 600; }

/* ---- header / nav ---- */

.site-header {
  border-bottom: 1px solid var(--hairline);
  background: var(--paper);
}
.site-header .inner {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.wordmark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
}
.wordmark .q { color: var(--kill); }
.site-nav { margin-left: auto; display: flex; align-items: center; gap: 1.4rem; }
.site-nav a {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
  text-decoration: none;
}
.site-nav a:hover { color: var(--ink); }
/* .site-nav a (0,1,1) outranks .btn-primary (0,1,0); restate button colors */
.site-nav a.btn-primary { color: var(--sheet); }
.site-nav a.btn-primary:hover { color: #fff; }
@media (max-width: 720px) {
  .site-nav a.nav-link { display: none; }
}

/* ---- buttons ---- */

.btn {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.86rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-decoration: none;
  text-align: center;
  padding: 0.8rem 1.5rem;
  border: 1.5px solid var(--ink);
  cursor: pointer;
  background: transparent;
  color: var(--ink);
  transition: background 0.15s, color 0.15s;
}
.btn-primary { background: var(--ink); color: var(--sheet); }
.btn-primary:hover { background: var(--kill); border-color: var(--kill); color: #fff; }
.btn:disabled {
  background: var(--ink-soft);
  border-color: var(--ink-soft);
  color: var(--sheet);
  cursor: default;
}
.btn-ghost:hover { background: var(--ink); color: var(--sheet); }
.btn-small { padding: 0.5rem 1rem; font-size: 0.76rem; }

/* ---- layout ---- */

.section {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 4.5rem 1.5rem;
}
.section + .section { border-top: 1px solid var(--hairline); }
.section-narrow { max-width: 860px; }

/* memo-style numbered section headers on the landing page */
.section-head {
  display: flex;
  align-items: baseline;
  gap: 1.2rem;
  margin-bottom: 2rem;
}
.section-no {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-faint);
  letter-spacing: 0.1em;
  white-space: nowrap;
  padding-top: 0.3rem;
}
.section-head h2 { margin: 0; }

/* ---- hero ---- */

.hero {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 4.5rem 1.5rem 5rem;
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: 4rem;
  align-items: center;
}
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 3rem; padding-top: 3rem; }
}
.hero-copy .lede { max-width: 34em; }
.hero-ctas { display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 2rem; align-items: center; }
.hero-note {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--ink-faint);
  margin-top: 1.1rem;
}

/* ---- the memo card (signature element) ---- */

.memo-card {
  position: relative;
  background: var(--sheet);
  border: 1px solid var(--hairline-dark);
  border-top: 3px double var(--ink);
  box-shadow: 0 1px 0 var(--hairline-dark), 0 14px 30px -18px rgba(26, 30, 34, 0.35);
  padding: 1.6rem 1.7rem 1.9rem;
  font-size: 0.86rem;
  max-width: 430px;
}
.memo-card-head {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid var(--hairline);
  padding-bottom: 0.6rem;
  margin-bottom: 0.9rem;
}
.memo-card-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.06rem;
  margin: 0 0 0.9rem;
}
.memo-line {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 0.42rem 0;
  border-bottom: 1px dotted var(--hairline);
}
.memo-line dt { color: var(--ink-soft); margin: 0; }
.memo-line dd { margin: 0; text-align: right; font-family: var(--font-mono); font-size: 0.76rem; }
.memo-card dl { margin: 0; }
.memo-quote {
  margin: 1.1rem 0 0;
  padding: 0.7rem 0.9rem;
  background: var(--kill-soft);
  border-left: 3px solid var(--kill);
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--ink);
}
.memo-quote cite {
  display: block;
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 0.66rem;
  color: var(--ink-faint);
  margin-top: 0.45rem;
}

/* verdict stamp */
.stamp {
  position: absolute;
  top: -1rem;
  right: -0.9rem;
  transform: rotate(-6deg);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 1.3rem;
  letter-spacing: 0.28em;
  padding: 0.35rem 0.9rem 0.35rem 1.15rem;
  color: var(--kill);
  border: 3px double var(--kill);
  background: rgba(253, 252, 248, 0.85);
  text-transform: uppercase;
}
.stamp-build { color: var(--build); border-color: var(--build); }

/* ---- evidence chips ---- */

.chip {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.12rem 0.45rem;
  border: 1px solid currentColor;
  border-radius: 2px;
  vertical-align: middle;
  white-space: nowrap;
}
.chip-fact { color: var(--build); background: var(--build-soft); }
.chip-estimate { color: var(--caution); background: var(--caution-soft); }
.chip-hypothesis { color: var(--ledger); background: var(--ledger-soft); }
.chip-unknown { color: var(--unknown); background: var(--unknown-soft); }
.chip-fail { color: var(--kill); background: var(--kill-soft); }
.chip-pass { color: var(--build); background: var(--build-soft); }

/* ---- comparison + generic tables ---- */

.doc-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  margin: 1.5rem 0;
  background: var(--sheet);
  border: 1px solid var(--hairline-dark);
}
.doc-table caption {
  caption-side: top;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
  padding-bottom: 0.5rem;
}
.doc-table th {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  text-align: left;
  color: var(--ink-soft);
  background: var(--paper);
  border-bottom: 2px solid var(--ink);
}
.doc-table th, .doc-table td {
  padding: 0.7rem 0.9rem;
  border-bottom: 1px solid var(--hairline);
  vertical-align: top;
}
.doc-table tbody tr:last-child td { border-bottom: none; }
.doc-table .num {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--ink-faint);
  white-space: nowrap;
}
.table-scroll { overflow-x: auto; }

/* ---- pricing ---- */

.pricing-sheet {
  background: var(--sheet);
  border: 1px solid var(--hairline-dark);
  border-top: 3px double var(--ink);
  max-width: 640px;
  margin: 0 auto;
  padding: 2.4rem 2.4rem 2.6rem;
}
.pricing-sheet .memo-card-head { margin-bottom: 1.4rem; }
.price-line {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin: 0 0 0.4rem;
}
.price-line .price {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 2.6rem;
  letter-spacing: -0.02em;
}
.price-line .price small {
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 0.74rem;
  color: var(--ink-faint);
  letter-spacing: 0.06em;
}
.included { list-style: none; margin: 1.4rem 0 1.8rem; padding: 0; }
.included li {
  padding: 0.55rem 0 0.55rem 1.6rem;
  border-bottom: 1px dotted var(--hairline);
  position: relative;
  font-size: 0.96rem;
}
.included li::before {
  content: "§";
  position: absolute;
  left: 0.15rem;
  font-family: var(--font-mono);
  color: var(--ledger);
  font-size: 0.8rem;
}
.pricing-sheet .btn { width: 100%; }
.guarantee {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
  text-align: center;
  margin-top: 0.9rem;
}
/* The refund term is the risk reversal, not fine print: it carries full ink
   weight while the surrounding terms stay quiet. */
.guarantee strong { color: var(--ink); }

/* ---- FAQ ---- */

.faq dt {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.08rem;
  margin: 1.8rem 0 0.4rem;
}
.faq dd { margin: 0; color: var(--ink-soft); max-width: 46em; }

/* ---- footer ---- */

.site-footer {
  border-top: 1px solid var(--hairline);
  margin-top: 2rem;
}
.site-footer .inner {
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 2rem 1.5rem 2.6rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 2rem;
  justify-content: space-between;
}
.site-footer a { color: var(--ink-soft); }

/* ==========================================================================
   Memo document pages (sample case, checkout)
   ========================================================================== */

.memo-page {
  max-width: var(--w-memo);
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
}
.memo-doc {
  background: var(--sheet);
  border: 1px solid var(--hairline-dark);
  border-top: 3px double var(--ink);
  box-shadow: 0 1px 0 var(--hairline-dark), 0 18px 40px -24px rgba(26, 30, 34, 0.3);
  padding: clamp(1.5rem, 5vw, 3.5rem);
  position: relative;
}
.memo-doc-head {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--hairline);
  padding-bottom: 1rem;
  margin-bottom: 2.2rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0.5rem 2rem;
}
.memo-doc-head div span { display: block; color: var(--ink-faint); font-size: 0.62rem; margin-bottom: 0.15rem; }
.memo-doc h1 { font-size: clamp(1.7rem, 3.6vw, 2.4rem); margin-bottom: 0.4em; }
.memo-doc h2 {
  font-size: 1.25rem;
  margin-top: 2.6em;
  padding-top: 1.4em;
  border-top: 1px solid var(--hairline);
}
.memo-doc h2 .sec-no {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--ink-faint);
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 0.5rem;
}
.memo-doc ul { padding-left: 1.2rem; }
.memo-doc li { margin-bottom: 0.4rem; }

.finding {
  margin: 1.6rem 0;
  padding: 1.1rem 1.3rem;
  border-left: 3px solid var(--ledger);
  background: var(--ledger-soft);
}
.finding-fatal { border-left-color: var(--kill); background: var(--kill-soft); }
.finding p:last-child { margin-bottom: 0; }
.finding .label {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--kill);
  display: block;
  margin-bottom: 0.4rem;
}
.finding blockquote {
  margin: 0.6rem 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--hairline-dark);
  font-family: var(--font-display);
  font-size: 1.02rem;
}

.verdict-block {
  margin: 2rem 0 0.5rem;
  border: 3px double var(--kill);
  padding: 1.6rem 1.8rem;
  position: relative;
  background: var(--sheet);
}
.verdict-block .verdict-word {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 2rem;
  letter-spacing: 0.3em;
  color: var(--kill);
  display: block;
  margin-bottom: 0.6rem;
}
.verdict-block p { margin-bottom: 0.5em; }

.memo-cta {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 3px double var(--ink);
  text-align: center;
}
.memo-cta .btn { margin-top: 1rem; }

/* ---- checkout ---- */

.checkout-steps { list-style: none; display: flex; gap: 1.5rem; padding: 0; margin: 0 0 2rem; }
.checkout-steps li {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
}
.checkout-steps li[aria-current="step"] { color: var(--kill); font-weight: 600; }

.order-line {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--hairline);
  gap: 1rem;
}
.order-line.total {
  border-bottom: 3px double var(--ink);
  font-weight: 600;
}
.order-line .amount { font-family: var(--font-mono); }

.email-step { margin-top: 1.8rem; }
.email-step[hidden] { display: none; }
.memo-doc h2.step-title {
  border-top: none;
  padding-top: 0;
  margin-top: 0;
  font-size: 1.15rem;
}
.email-form { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-top: 1rem; }
.email-form[hidden] { display: none; }
.email-form input[type="email"] {
  flex: 1 1 240px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  padding: 0.75rem 0.9rem;
  border: 1.5px solid var(--ink);
  background: var(--sheet);
  color: var(--ink);
}
.email-form input[type="email"]:focus-visible { outline-offset: 0; }
.form-note { font-size: 0.82rem; color: var(--ink-faint); margin-top: 0.8rem; }
.capture-done {
  border-left: 3px solid var(--build);
  background: var(--build-soft);
  padding: 1rem 1.2rem;
  margin-top: 1rem;
}
.capture-done[hidden] { display: none; }

/* sample end sentinel is invisible but must occupy layout for the observer */
.memo-end-sentinel { height: 1px; }

/* ---- utilities ---- */

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.after-cta-note {
  font-size: 0.85rem;
  color: var(--ink-soft);
  text-align: center;
  margin: 0.9rem 0 0;
}

/* ---- print: the memo should read as an actual document ---- */

@media print {
  .classification, .site-header, .site-footer, .memo-cta,
  .hero-ctas, .btn, .skip-link { display: none !important; }
  body { background: #fff; font-size: 11pt; }
  .memo-doc, .memo-card, .pricing-sheet {
    box-shadow: none;
    border-color: #999;
  }
  .memo-doc { padding: 0; border: none; }
  a { color: inherit; text-decoration: none; }
  .doc-table th { background: #fff; }
}