/* ==========================================================
   Degreed but Disposable — design tokens
   Paper + ink + one restrained stamp-red accent.
   ========================================================== */

:root {
  --paper: #F5F2EB;
  --paper-deep: #ECE6D9;
  --ink: #18150F;
  --ink-soft: #55503F;
  --ink-faint: #8C8674;
  --line: #D9D1BC;
  --line-strong: #B9AF95;
  --stamp: #7A2E1E;
  --stamp-soft: rgba(122, 46, 30, 0.08);
  --paper-rgb: 245, 242, 235;

  --font-display: "Fraunces", "Iowan Old Style", "Palatino Linotype", serif;
  --font-body: "Inter", -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", "SF Mono", monospace;

  --max-w: 1180px;
  --gutter: clamp(20px, 6vw, 72px);
}

@media (prefers-color-scheme: dark) {
  :root { /* Intentionally not inverted — the book keeps its paper tone regardless of system theme. */ }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: inherit; }

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

/* -------------------- Type scale -------------------- */

.eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

h1, h2, h3 { font-family: var(--font-display); margin: 0; font-weight: 500; }

.display-title {
  font-size: clamp(42px, 7vw, 84px);
  line-height: 1.04;
  letter-spacing: -0.01em;
  font-weight: 480;
}

.display-title em {
  font-style: italic;
  color: var(--stamp);
}

.section-title {
  font-size: clamp(28px, 3.4vw, 40px);
  line-height: 1.14;
}

p.lede {
  font-size: clamp(17px, 1.6vw, 20px);
  color: var(--ink-soft);
  max-width: 46ch;
  line-height: 1.65;
}

/* -------------------- Nav -------------------- */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(var(--paper-rgb), 0.86);
  backdrop-filter: saturate(140%) blur(6px);
  border-bottom: 1px solid var(--line);
}

.site-nav .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.site-nav .brand {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 60vw;
}

.site-nav .nav-actions {
  display: flex;
  gap: 10px;
}

/* -------------------- Buttons -------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid var(--ink);
  padding: 13px 22px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink);
  background: transparent;
  cursor: pointer;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease;
  white-space: nowrap;
}

.btn:hover { background: var(--ink); color: var(--paper); }

.btn.btn-primary { background: var(--ink); color: var(--paper); }
.btn.btn-primary:hover { background: var(--stamp); border-color: var(--stamp); color: var(--paper); }

.btn.btn-quiet {
  border-color: var(--line-strong);
  color: var(--ink-soft);
  padding: 10px 16px;
  font-size: 11px;
}
.btn.btn-quiet:hover { background: var(--ink); border-color: var(--ink); color: var(--paper); }

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

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

.hero {
  padding: 64px 0 96px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(32px, 6vw, 80px);
  align-items: center;
}

.hero-copy .eyebrow { margin-bottom: 22px; }

.hero-copy .display-title { margin-bottom: 20px; }

.hero-copy .subtitle {
  font-family: var(--font-display);
  font-size: clamp(18px, 2vw, 23px);
  font-style: italic;
  color: var(--ink-soft);
  margin-bottom: 10px;
}

.hero-copy .byline {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 40px;
}

.hero-copy .byline::before {
  content: "";
  display: inline-block;
  width: 22px;
  height: 1px;
  background: var(--line-strong);
  margin-right: 12px;
  vertical-align: middle;
}

/* -------------------- Book object + stamp -------------------- */

.book-figure {
  position: relative;
  display: flex;
  justify-content: center;
}

.book-cover {
  width: min(340px, 78vw);
  border: 1px solid var(--line-strong);
  padding: 10px;
  background: var(--paper);
  transition: transform 420ms cubic-bezier(.2,.8,.2,1);
}

.book-cover img, .book-cover svg { width: 100%; height: auto; display: block; }

.book-figure:hover .book-cover { transform: translateY(-4px) rotate(-0.6deg); }

.stamp {
  position: absolute;
  width: 118px;
  height: 118px;
  top: -18px;
  right: -6px;
  transform: rotate(-9deg);
  pointer-events: none;
  opacity: 0.92;
}

@media (max-width: 720px) {
  .stamp { width: 92px; height: 92px; top: -12px; right: 4px; }
}

/* -------------------- Sections -------------------- */

section { padding: 88px 0; }

.section-alt { background: var(--paper-deep); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section-head {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 48px;
  margin-bottom: 48px;
}

@media (max-width: 860px) {
  .section-head { grid-template-columns: 1fr; gap: 20px; }
}

.rule {
  border: none;
  border-top: 1px solid var(--line);
  margin: 0;
}

/* ---- The Book ---- */

.facts-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.fact-cell {
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 22px 20px;
}

.fact-cell .eyebrow { margin-bottom: 8px; }
.fact-cell .value { font-family: var(--font-display); font-size: 20px; }

@media (max-width: 720px) {
  .facts-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ---- Read online ---- */

.read-panel {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: clamp(32px, 5vw, 64px);
  align-items: start;
}

@media (max-width: 860px) { .read-panel { grid-template-columns: 1fr; } }

.toc-list { list-style: none; margin: 28px 0 0; padding: 0; border-top: 1px solid var(--line); }

.toc-list li {
  border-bottom: 1px solid var(--line);
}

.toc-list a {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 16px 4px;
  text-decoration: none;
  color: var(--ink);
  transition: color 150ms ease, padding-left 150ms ease;
}

.toc-list a:hover { color: var(--stamp); padding-left: 8px; }

.toc-num { font-family: var(--font-mono); font-size: 12px; color: var(--ink-faint); flex-shrink: 0; width: 2.4em; }
.toc-name { font-family: var(--font-display); font-size: 17px; flex: 1; }
.toc-words { font-family: var(--font-mono); font-size: 11px; color: var(--ink-faint); }

/* ---- Download ---- */

.file-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  border: 1px solid var(--line-strong);
  padding: 24px 28px;
}

.file-row + .file-row { border-top: none; }

.file-meta .label { font-family: var(--font-display); font-size: 20px; margin-bottom: 4px; }
.file-meta .sub { font-family: var(--font-mono); font-size: 12px; color: var(--ink-soft); letter-spacing: 0.04em; }

/* ---- Physical copy ---- */

.physical-panel {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
}
@media (max-width: 860px) { .physical-panel { grid-template-columns: 1fr; } }

.price-tag {
  font-family: var(--font-mono);
  font-size: 34px;
  letter-spacing: 0.02em;
  color: var(--stamp);
  margin: 8px 0 28px;
}

/* ---- Author ---- */

.author-panel {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px;
  align-items: start;
}
@media (max-width: 640px) { .author-panel { grid-template-columns: 1fr; } }

.author-portrait {
  width: 100%;
  aspect-ratio: 3/4;
  border: 1px solid var(--line-strong);
  background: var(--paper-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-faint);
  text-align: center;
  padding: 10px;
  overflow: hidden;
}

.author-portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ---- Closing ---- */

.closing {
  text-align: center;
  padding: 120px 0 100px;
}

.closing .display-title { margin-bottom: 8px; }
.closing .subtitle { font-family: var(--font-display); font-style: italic; font-size: clamp(17px, 2vw, 21px); color: var(--ink-soft); margin-bottom: 6px; }
.closing .byline { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-faint); margin-bottom: 44px; }
.closing .action-row { justify-content: center; }

footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
}

footer a { text-decoration: none; }
footer a:hover { color: var(--stamp); }

/* -------------------- Reveal-on-scroll -------------------- */

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 700ms ease, transform 700ms ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

/* -------------------- Focus visibility -------------------- */

a:focus-visible, button:focus-visible, .btn:focus-visible {
  outline: 2px solid var(--stamp);
  outline-offset: 3px;
}

@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero { padding: 40px 0 64px; }
  .book-figure { order: -1; margin-bottom: 8px; }
  section { padding: 64px 0; }
}