/* Keyed Books — one-pager. Ledger paper aesthetic. */

:root {
  --paper:      #F6F1E7;
  --paper-tint: color-mix(in oklch, #F6F1E7 90%, #1F5F4A 10%);
  --ink:        #1C1A17;
  --ink-soft:   color-mix(in oklch, #1C1A17 62%, #F6F1E7 38%);
  --ink-faint:  color-mix(in oklch, #1C1A17 40%, #F6F1E7 60%);
  --green:      #1F5F4A;
  --green-soft: color-mix(in oklch, #1F5F4A 55%, #F6F1E7 45%);
  --rule:       color-mix(in oklch, #1C1A17 16%, #F6F1E7 84%);
  --rule-deep:  color-mix(in oklch, #1C1A17 26%, #F6F1E7 74%);

  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: "Vollkorn", Georgia, "Times New Roman", serif;
}

* { box-sizing: border-box; }

html {
  background: var(--paper);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

a { color: var(--green); }

.screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: var(--space-3xl) var(--space-lg);
}

.wrap {
  max-width: 640px;
  margin: 0 auto;
  width: 100%;
}

/* Alternating ledger-paper tone between screens for rhythm */
.mechanism, .fit { background: var(--paper-tint); }

/* Thin horizontal ledger rule, used sparingly */
.rule {
  height: 1px;
  background: var(--rule-deep);
  margin: var(--space-xl) 0;
}

/* ---------- Hero ---------- */

.hero .wrap { text-align: left; }

.kicker {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--green);
  margin: 0 0 var(--space-lg);
  display: flex;
  align-items: center;
  gap: 8px;
  opacity: 0;
  animation: rise 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.05s forwards;
}

.kicker .mark {
  width: 13px;
  height: 19.5px;
  fill: var(--green);
  flex: 0 0 auto;
}

.hero h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(2.1rem, 5vw + 1rem, 3.6rem);
  line-height: 1.08;
  letter-spacing: -0.01em;
  margin: 0;
  color: var(--ink);
  opacity: 0;
  animation: rise 0.8s cubic-bezier(0.16, 1, 0.3, 1) 0.18s forwards;
}

.hero .sub {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 500;
  font-size: clamp(1.15rem, 1.6vw + 0.8rem, 1.5rem);
  color: var(--ink-soft);
  margin: var(--space-lg) 0 0;
  max-width: 30ch;
  opacity: 0;
  animation: rise 0.8s cubic-bezier(0.16, 1, 0.3, 1) 0.32s forwards;
}

.hero .rule {
  max-width: 120px;
  margin: var(--space-2xl) 0 var(--space-lg);
  opacity: 0;
  animation: rise 0.8s cubic-bezier(0.16, 1, 0.3, 1) 0.44s forwards;
}

.scroll-cue {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
  text-decoration: none;
  border-bottom: 1px solid var(--rule-deep);
  padding-bottom: 2px;
  opacity: 0;
  animation: rise 0.8s cubic-bezier(0.16, 1, 0.3, 1) 0.56s forwards;
}

.scroll-cue:hover { color: var(--green); border-color: var(--green); }

@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---------- Mechanism (three steps) ---------- */

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: none;
}

.steps li {
  display: flex;
  gap: var(--space-lg);
  align-items: baseline;
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--rule);
}

.steps li:first-child { padding-top: 0; }
.steps li:last-child { border-bottom: none; }

.steps .num {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--green);
  flex: 0 0 auto;
  min-width: 2.2ch;
  font-variant-numeric: tabular-nums;
}

.steps p {
  margin: 0;
  font-size: 1.08rem;
  line-height: 1.55;
  color: var(--ink);
  max-width: 46ch;
}

/* ---------- Offer ---------- */

.offer .wrap { text-align: left; }

.price {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(3rem, 9vw, 5.5rem);
  line-height: 1;
  margin: 0;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.price-unit {
  font-family: var(--sans);
  font-weight: 500;
  font-size: 1.05rem;
  color: var(--ink-soft);
  margin-left: var(--space-sm);
  letter-spacing: 0.01em;
}

.offer-line {
  font-size: 1.15rem;
  color: var(--ink);
  margin: var(--space-md) 0 0;
}

.offer .rule {
  border-top: 1px solid var(--rule-deep);
  border-bottom: 1px solid var(--rule-deep);
  background: none;
  height: 0;
  max-width: 100%;
  margin: var(--space-xl) 0;
}

.offer-detail {
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--ink-soft);
  margin: 0;
  max-width: 46ch;
}

/* ---------- For / Not for ---------- */

.fit-grid {
  display: flex;
  flex-direction: column;
}

.fit-col {
  padding: var(--space-lg) 0;
}

.fit-col:first-child { padding-top: 0; }

.fit-label {
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--green);
  margin: 0 0 var(--space-sm);
}

.fit-col p:last-child {
  margin: 0;
  font-size: 1.08rem;
  line-height: 1.55;
  color: var(--ink);
  max-width: 42ch;
}

.fit-divider {
  height: 1px;
  background: var(--rule-deep);
}

/* ---------- Ask ---------- */

.ask .wrap { text-align: left; }

.ask h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.7rem, 3.6vw + 1rem, 2.5rem);
  line-height: 1.18;
  margin: 0 0 var(--space-xl);
  color: var(--ink);
  max-width: 20ch;
}

.mailto-btn {
  display: inline-block;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.98rem;
  letter-spacing: 0.02em;
  color: var(--paper);
  background: var(--ink);
  text-decoration: none;
  padding: 14px 26px;
  border: 1px solid var(--ink);
  transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s cubic-bezier(0.16,1,0.3,1);
}

.mailto-btn:hover {
  background: var(--green);
  border-color: var(--green);
  transform: translateY(-1px);
}

.ask-note {
  margin: var(--space-lg) 0 0;
  font-size: 0.92rem;
  color: var(--ink-faint);
}

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

.colophon {
  min-height: auto;
  padding: var(--space-3xl) var(--space-lg);
  background: var(--ink);
}

.about-row {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.portrait {
  width: 64px;
  height: 64px;
  border-radius: 2px;
  object-fit: cover;
  flex: 0 0 auto;
  filter: grayscale(8%);
}

.about-text p {
  margin: 0;
  color: var(--paper);
  font-size: 0.95rem;
  line-height: 1.5;
}

.about-text p + p {
  margin-top: var(--space-xs);
  color: color-mix(in oklch, #F6F1E7 55%, #1C1A17 45%);
  font-size: 0.85rem;
}

/* ---------- Wider screens ---------- */

@media (min-width: 720px) {
  .screen { padding: var(--space-4xl) var(--space-2xl); }

  .fit-grid {
    flex-direction: row;
    align-items: stretch;
    gap: var(--space-3xl);
  }

  .fit-col { flex: 1; padding: 0; }
  .fit-col:first-child { padding-top: 0; }

  .fit-divider { width: 1px; height: auto; align-self: stretch; }

  .price { font-size: clamp(4rem, 7vw, 6.5rem); }
}