/* golang-agents.com: the palette and type of the book cover. The theme
   follows the system setting; the header toggle overrides it, and the
   light theme is the light edition of the book. */

@font-face {
  font-family: "Cinzel";
  src: url("fonts/cinzel-latin-600-normal.woff2") format("woff2");
  font-weight: 600;
  font-display: swap;
}
@font-face {
  font-family: "Inter";
  src: url("fonts/inter-latin-wght-normal.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Space Grotesk";
  src: url("fonts/space-grotesk-latin-500-normal.woff2") format("woff2");
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: "Space Grotesk";
  src: url("fonts/space-grotesk-latin-600-normal.woff2") format("woff2");
  font-weight: 600;
  font-display: swap;
}

:root {
  --night: #040e19;
  --page: #071321;
  --panel: #0d1d30;
  --panel-deep: #0a1828;
  --line: #1e3550;
  --ivory: #f3ead6;
  --stone: #dad4c6;
  --soft: #9aa4af;
  --amber: #e9ae55;
  --amber-dim: rgba(233, 174, 85, 0.55);
  --amber-ink: #1a1206;
  --link: #7ccde8;
  --line-soft: rgba(30, 53, 80, 0.6);
  --accent-wash: rgba(233, 174, 85, 0.12);
  --accent-ring: rgba(233, 174, 85, 0.18);
  --button-hover: #f2c079;
  --outline-soft: rgba(243, 234, 214, 0.5);
  --outline-wash: rgba(243, 234, 214, 0.06);
  --hero-top: #030b14;
  --hero-glow: rgba(18, 48, 84, 0.55);
  --buy-top: #102440;
  --shadow: rgba(0, 0, 0, 0.7);
  --cover-glow: rgba(40, 90, 150, 0.22);
  --stars: 0.55;
  /* Syntax colors: the dark edition of the book. */
  --code-bg: #0d1d30;
  --syn-keyword: #bba5f0;
  --syn-type: #ebc170;
  --syn-constant: #eaa6c4;
  --syn-string: #8fd4b8;
  --syn-number: #f2a57e;
  --syn-comment: #8494a8;
  --syn-function: #82cbe6;
  --syn-key: #82cbe6;
  --syn-punct: #a7b0bc;
  --display: "Cinzel", "Trajan Pro", Georgia, serif;
  --label: "Space Grotesk", system-ui, sans-serif;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --gutter: clamp(1rem, 4vw, 2.5rem);
  --page-max: 80rem; /* the widest the page grows */
  --measure: 46rem; /* body text: about 90 characters a line */
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  margin: 0;
  background: var(--page);
  color: var(--stone);
  font-family: var(--body);
  font-size: 1.0625rem;
  line-height: 1.65;
  font-feature-settings: "cv11", "ss01";
  overflow-wrap: break-word;
}

img { display: block; max-width: 100%; height: auto; }

h1, h2, h3, h4 { color: var(--ivory); line-height: 1.2; margin: 0; text-wrap: balance; }

h1, h2 {
  font-family: var(--display);
  font-weight: 600;
  font-feature-settings: normal;
  letter-spacing: 0.01em;
}
h2 { font-size: clamp(1.7rem, 4.2vw, 2.5rem); margin-bottom: 1.25rem; }
h3 { font-family: var(--label); font-weight: 600; font-size: 1.15rem; }
h4 { font-family: var(--label); font-weight: 600; font-size: 1.05rem; }

p { margin: 0 0 1rem; }

a { color: var(--link); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }

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

code {
  font-family: var(--mono);
  font-size: 0.9em;
  color: var(--ivory);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.05em 0.35em;
}

cite { font-style: italic; }

.wrap {
  width: 100%;
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.narrow > * { max-width: 44rem; }

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 10;
  background: var(--amber);
  color: var(--amber-ink);
  padding: 0.5rem 1rem;
  font-weight: 600;
  border-radius: 4px;
}
.skip:focus { top: 1rem; }

/* Labels: the cover subtitle's letterspaced amber capitals. */
.eyebrow, .part-label, .cite, .subtitle {
  font-family: var(--label);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--amber);
}
.eyebrow { font-size: 0.8rem; margin-bottom: 0.75rem; }

/* The cover's ring ornament between two hairlines. */
.ornament {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  max-width: 15rem;
  margin: 1.25rem 0;
}
.ornament::before, .ornament::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--amber-dim);
}
.ornament span {
  flex: none;
  width: 18px;
  height: 18px;
  border: 2px solid var(--amber);
  border-radius: 50%;
  display: grid;
  place-items: center;
}
.ornament span::after {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
}

/* Header: the brand and the theme toggle, with the section nav beside
   them on wide screens and in a scrolling strip below them on narrow ones. */
.site-header {
  border-bottom: 1px solid var(--line-soft);
  background: var(--night);
}
.header-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  column-gap: 1rem;
  min-height: 3.75rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 3.75rem;
  font-family: var(--display);
  font-weight: 600;
  font-feature-settings: normal;
  color: var(--ivory);
  text-decoration: none;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.brand-ring {
  flex: none;
  width: 16px;
  height: 16px;
  border: 2px solid var(--amber);
  border-radius: 50%;
  display: grid;
  place-items: center;
}
.brand-ring::after {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--amber);
}
.theme-toggle {
  margin-left: auto;
  display: inline-grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: transparent;
  color: var(--stone);
  cursor: pointer;
}
.theme-toggle[hidden] { display: none; }
.theme-toggle:hover { color: var(--ivory); border-color: var(--amber-dim); }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="light"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="light"] .theme-toggle .icon-moon { display: block; }
.site-nav {
  flex: 1 1 100%;
  margin: 0 calc(-1 * var(--gutter));
  padding: 0 var(--gutter);
  overflow-x: auto;
  scrollbar-width: none;
  border-top: 1px solid var(--line-soft);
}
.site-nav::-webkit-scrollbar { display: none; }
.site-nav ul {
  display: flex;
  gap: 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
  white-space: nowrap;
}
.site-nav a {
  display: block;
  padding: 0.7rem 0;
  font-family: var(--label);
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--stone);
  text-decoration: none;
  border-bottom: 2px solid transparent;
}
.site-nav a:hover { color: var(--ivory); }
.site-nav a[aria-current="page"] { color: var(--ivory); border-bottom-color: var(--amber); }
.site-nav a.nav-book { color: var(--amber); }
@media (min-width: 72rem) {
  .header-row { flex-wrap: nowrap; }
  .site-nav { order: 2; flex: 0 1 auto; margin: 0 0 0 auto; padding: 0; border-top: 0; overflow: visible; }
  .site-nav a { padding: 1.1rem 0 1rem; }
  .theme-toggle { order: 3; margin-left: 0.5rem; }
}
@media (max-width: 23rem) {
  .brand { font-size: 0.95rem; }
  .site-nav ul { gap: 1rem; }
}

/* Hero: the cover's navy with a soft blue glow and a sparse star field. */
.hero {
  position: relative;
  overflow: hidden;
  padding: clamp(2.5rem, 7vw, 6rem) 0 clamp(3rem, 8vw, 6.5rem);
  background:
    radial-gradient(ellipse 60% 70% at 78% 45%, var(--hero-glow), transparent 70%),
    linear-gradient(180deg, var(--hero-top) 0%, var(--night) 50%, var(--page) 100%);
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: var(--stars);
  background-image:
    radial-gradient(1px 1px at 12% 18%, var(--ivory), transparent),
    radial-gradient(1px 1px at 31% 8%, var(--stone), transparent),
    radial-gradient(1px 1px at 47% 27%, var(--ivory), transparent),
    radial-gradient(1.5px 1.5px at 63% 12%, var(--ivory), transparent),
    radial-gradient(1px 1px at 82% 6%, var(--stone), transparent),
    radial-gradient(1px 1px at 92% 31%, var(--ivory), transparent),
    radial-gradient(1px 1px at 7% 62%, var(--stone), transparent),
    radial-gradient(1px 1px at 22% 84%, var(--ivory), transparent),
    radial-gradient(1px 1px at 54% 92%, var(--stone), transparent),
    radial-gradient(1.5px 1.5px at 38% 55%, var(--stone), transparent);
}
.hero-grid {
  position: relative;
  display: grid;
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}
.hero h1 {
  font-size: clamp(2.25rem, 7.4vw, 4.25rem);
  line-height: 1.08;
}
.hero .subtitle {
  font-size: clamp(0.8rem, 2.4vw, 0.98rem);
  margin: 1rem 0 0;
  letter-spacing: 0.22em;
}
.hook {
  font-size: clamp(1.3rem, 3.4vw, 1.7rem);
  line-height: 1.4;
  color: var(--ivory);
  max-width: 30ch;
}
.lede { color: var(--stone); max-width: 38rem; }
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin: 1.75rem 0;
}
@media (max-width: 29.99rem) {
  .actions .button { flex: 1 1 100%; }
}
.facts {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--label);
  font-size: 0.9rem;
  color: var(--soft);
}
.facts li { display: flex; align-items: center; gap: 0.5rem; }
.facts li::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--amber);
  flex: none;
}
.hero-cover { order: -1; justify-self: center; width: min(210px, 56vw); }
.hero-cover img {
  border-radius: 3px;
  box-shadow:
    0 0 0 1px var(--amber-dim),
    0 24px 50px -12px var(--shadow),
    0 0 90px var(--cover-glow);
}
@media (min-width: 37.5rem) {
  .hero-cover { width: 300px; }
}
@media (min-width: 60rem) {
  .hero-grid { grid-template-columns: minmax(0, 1fr) 420px; }
  .hero h1 { font-size: clamp(2.6rem, 4.6vw, 4.25rem); }
  .hero-cover { order: 0; width: 420px; }
}

/* Buttons */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3rem;
  padding: 0.7rem 1.4rem;
  border-radius: 4px;
  font-family: var(--label);
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: 0.02em;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
}
.button.primary { background: var(--amber); color: var(--amber-ink); }
.button.primary:hover { background: var(--button-hover); }
.button.secondary { color: var(--ivory); border-color: var(--outline-soft); background: transparent; }
.button.secondary:hover { border-color: var(--ivory); background: var(--outline-wash); }
.button.block { width: 100%; }
@media (prefers-reduced-motion: no-preference) {
  .button { transition: background-color 0.15s, border-color 0.15s; }
}

/* Sections */
.section { padding: clamp(3.5rem, 8vw, 6rem) 0; }
.section.alt {
  background: var(--panel-deep);
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}
.big { font-size: clamp(1.08rem, 2.2vw, 1.2rem); }
.note { color: var(--soft); font-size: 0.95rem; margin-top: 1.5rem; }
.small { font-size: 0.875rem; color: var(--soft); }

/* The four stages */
.stages-title { margin: 2.5rem 0 1.25rem; }
.stages {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr));
}
.stages li {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--amber);
  border-radius: 4px;
  padding: 1.25rem 1.25rem 1rem;
}
.stage-n {
  display: inline-grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border: 2px solid var(--amber);
  border-radius: 50%;
  color: var(--amber);
  font-family: var(--label);
  font-weight: 600;
  margin-bottom: 0.75rem;
}
.stages h4 { margin-bottom: 0.4rem; }
.stages p { margin: 0; font-size: 0.97rem; }
@media (max-width: 39.99rem) {
  .stages li {
    display: grid;
    grid-template-columns: 2rem minmax(0, 1fr);
    column-gap: 0.9rem;
    padding: 1rem 1.1rem;
    border-top-width: 1px;
    border-left: 3px solid var(--amber);
  }
  .stage-n { grid-row: span 2; margin: 0; }
}

/* Parts and the checklist */
.parts {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 18rem), 1fr));
}
.parts li {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1.5rem;
}
.part-label { font-size: 0.75rem; margin-bottom: 0.4rem; }
.parts h3 {
  font-family: var(--display);
  font-feature-settings: normal;
  font-size: 1.45rem;
  margin-bottom: 0.75rem;
}
.parts p:last-child { margin: 0; }
.checklist-title { margin: 2.75rem 0 1rem; }
.checklist {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.6rem 2rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 22rem), 1fr));
}
.checklist li {
  position: relative;
  padding-left: 1.6rem;
}
.checklist li::before {
  content: "";
  position: absolute;
  left: 0.2rem;
  top: 0.55em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 3px var(--accent-ring);
}

/* Findings */
.findings {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 30rem), 1fr));
}
.findings li {
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  border-radius: 4px;
  padding: 1.5rem 1.5rem 1.25rem;
  display: flex;
  flex-direction: column;
}
.findings .figure {
  font-family: var(--display);
  font-feature-settings: normal;
  font-weight: 600;
  font-size: clamp(2.2rem, 6vw, 2.8rem);
  line-height: 1;
  color: var(--amber);
  margin-bottom: 0.9rem;
}
.findings .figure span {
  font-family: var(--label);
  font-weight: 500;
  font-size: 1rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--stone);
}
.findings h3 { font-size: 1.12rem; line-height: 1.4; margin-bottom: 0.75rem; }
.findings p { font-size: 0.97rem; }
.findings .cite { font-size: 0.72rem; margin: auto 0 0; padding-top: 0.5rem; }

/* Contents */
.toc { display: grid; gap: 1.25rem; margin-top: 1rem; }
.toc-part {
  display: grid;
  gap: 1rem 2.5rem;
  border-top: 1px solid var(--line);
  padding-top: 1.75rem;
}
.toc-head h3 {
  font-family: var(--display);
  font-feature-settings: normal;
  font-size: 1.6rem;
  margin-bottom: 0.3rem;
}
.toc-head p:last-child { color: var(--soft); font-size: 0.9rem; margin: 0; }
.toc-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: chapter;
  display: grid;
  gap: 0.25rem;
}
.toc-list[start="7"] { counter-reset: chapter 6; }
.toc-list[start="11"] { counter-reset: chapter 10; }
.toc-list li {
  counter-increment: chapter;
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  column-gap: 0.75rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line-soft);
}
.toc-list li:last-child { border-bottom: 0; }
.toc-list li::before {
  content: counter(chapter, decimal-leading-zero);
  grid-row: span 2;
  font-family: var(--label);
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--amber);
  line-height: 1.35;
}
.toc-list h4 { font-size: 1.05rem; margin-bottom: 0.2rem; }
.toc-list p { margin: 0; color: var(--soft); font-size: 0.95rem; }
@media (min-width: 52rem) {
  .toc-part { grid-template-columns: 14rem minmax(0, 1fr); }
}

/* What you get */
.get-grid {
  display: grid;
  gap: 1.5rem;
  align-items: start;
}
.formats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
}
.formats li {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1.25rem;
}
.formats li.wide { grid-column: 1 / -1; }
.formats h3 { margin-bottom: 0.4rem; }
.formats p { margin: 0; font-size: 0.97rem; }
.buy-box {
  background: linear-gradient(180deg, var(--buy-top), var(--panel));
  border: 1px solid var(--amber-dim);
  border-radius: 6px;
  padding: 1.75rem;
  box-shadow: 0 20px 40px -20px var(--shadow);
}
.buy-title {
  font-family: var(--display);
  font-feature-settings: normal;
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--ivory);
  margin-bottom: 0.3rem;
}
.buy-formats { color: var(--soft); font-size: 0.95rem; }
.price {
  margin: 1.25rem 0;
  font-family: var(--display);
  font-weight: 600;
  font-size: 2.5rem;
  line-height: 1;
  color: var(--ivory);
}
.buy-box .small { margin: 1rem 0 0; }
@media (min-width: 60rem) {
  .get-grid { grid-template-columns: minmax(0, 1fr) 20rem; }
  .buy-box { position: sticky; top: 1.5rem; }
}

/* Sample */
.sample-list {
  list-style: none;
  margin: 1.5rem 0 2rem;
  padding: 0;
  display: grid;
  gap: 0.9rem;
}
.sample-list li {
  border-left: 3px solid var(--amber);
  background: var(--panel);
  border-radius: 0 4px 4px 0;
  padding: 1rem 1.25rem;
}
.sample-list h3 { font-size: 1.05rem; margin-bottom: 0.3rem; }
.sample-list p { margin: 0; font-size: 0.97rem; }

/* Author */
.author .ornament { margin: 0 0 1.5rem; }
.ring-only { max-width: 9rem; }

/* FAQ */
.faq { display: grid; gap: 0.75rem; }
.faq details {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
}
.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 1rem 3rem 1rem 1.25rem;
  position: relative;
  font-family: var(--label);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ivory);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  position: absolute;
  right: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.4rem;
  font-weight: 500;
  color: var(--amber);
}
.faq details[open] summary::after { content: "\2212"; }
.faq details > p { padding: 0 1.25rem; }
.faq details > p:last-child { padding-bottom: 0.25rem; }

/* Footer */
.site-footer {
  background: var(--night);
  border-top: 1px solid var(--line);
  padding: 2.5rem 0 3rem;
  font-size: 0.9rem;
  color: var(--soft);
}
.site-footer p { margin: 0 0 0.5rem; }
.footer-title {
  font-family: var(--display);
  font-feature-settings: normal;
  font-weight: 600;
  color: var(--ivory);
}
.footer-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 16rem), 1fr));
}

/* The light theme: the light edition of the book, on white. */
:root[data-theme="light"] {
  --night: #fbfaf7;
  --page: #ffffff;
  --panel: #f6f4ef;
  --panel-deep: #faf8f3;
  --line: #ddd6c8;
  --line-soft: #e8e2d6;
  --ivory: #08192b;
  --stone: #1b2633;
  --soft: #56616e;
  --amber: #965a0c;
  --amber-dim: rgba(160, 98, 15, 0.45);
  --amber-ink: #ffffff;
  --link: #0077a3;
  --accent-wash: rgba(160, 98, 15, 0.08);
  --accent-ring: rgba(160, 98, 15, 0.16);
  --button-hover: #87520c;
  --outline-soft: rgba(8, 25, 43, 0.45);
  --outline-wash: rgba(8, 25, 43, 0.04);
  --hero-top: #fbf8f2;
  --hero-glow: rgba(233, 174, 85, 0.14);
  --buy-top: #fbf3e4;
  --shadow: rgba(8, 25, 43, 0.2);
  --cover-glow: rgba(160, 98, 15, 0.12);
  --stars: 0;
  --code-bg: #f6f4ef;
  --syn-keyword: #6d28d9;
  --syn-type: #a04e08;
  --syn-constant: #be185d;
  --syn-string: #0f7363;
  --syn-number: #b23c0a;
  --syn-comment: #646c76;
  --syn-function: #03649a;
  --syn-key: #03649a;
  --syn-punct: #52606d;
  color-scheme: light;
}

/* With no choice made in the toggle, follow the system setting. */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --night: #fbfaf7;
    --page: #ffffff;
    --panel: #f6f4ef;
    --panel-deep: #faf8f3;
    --line: #ddd6c8;
    --line-soft: #e8e2d6;
    --ivory: #08192b;
    --stone: #1b2633;
    --soft: #56616e;
    --amber: #965a0c;
    --amber-dim: rgba(160, 98, 15, 0.45);
    --amber-ink: #ffffff;
    --link: #0077a3;
    --accent-wash: rgba(160, 98, 15, 0.08);
    --accent-ring: rgba(160, 98, 15, 0.16);
    --button-hover: #87520c;
    --outline-soft: rgba(8, 25, 43, 0.45);
    --outline-wash: rgba(8, 25, 43, 0.04);
    --hero-top: #fbf8f2;
    --hero-glow: rgba(233, 174, 85, 0.14);
    --buy-top: #fbf3e4;
    --shadow: rgba(8, 25, 43, 0.2);
    --cover-glow: rgba(160, 98, 15, 0.12);
    --stars: 0;
    --code-bg: #f6f4ef;
    --syn-keyword: #6d28d9;
    --syn-type: #a04e08;
    --syn-constant: #be185d;
    --syn-string: #0f7363;
    --syn-number: #b23c0a;
    --syn-comment: #646c76;
    --syn-function: #03649a;
    --syn-key: #03649a;
    --syn-punct: #52606d;
    color-scheme: light;
  }
  :root:not([data-theme="dark"]) .theme-toggle .icon-sun { display: none; }
  :root:not([data-theme="dark"]) .theme-toggle .icon-moon { display: block; }
}


/* Guides, section pages, and the glossary */
.guide, .section-page { padding: clamp(2.25rem, 6vw, 4rem) 0 clamp(3rem, 7vw, 5rem); }
.guide-head { max-width: var(--measure); margin-bottom: 2.25rem; }
.guide-head .lede { max-width: none; }
.guide-head .eyebrow a { color: inherit; text-decoration: none; }
.guide-head .eyebrow a:hover { text-decoration: underline; }
.guide-head h1 {
  font-size: clamp(1.8rem, 4.6vw, 2.6rem);
  line-height: 1.15;
  margin-bottom: 1rem;
}
.guide-head .lede {
  font-size: clamp(1.08rem, 2.4vw, 1.22rem);
  line-height: 1.55;
  color: var(--ivory);
}
.meta { font-family: var(--label); font-size: 0.88rem; color: var(--soft); margin: 0; }

/* Text keeps to the measure, about 90 characters a line; code, tables,
   rows of result cards, and the when-to-use blocks may run wider, up to
   the column's width. A single result card keeps to the measure, since
   it is mostly text. */
.prose { max-width: 60rem; }
.prose > * { max-width: var(--measure); }
.prose > .listing, .prose > table, .prose > .table-scroll,
.prose > .result-cards, .prose > .fit, .prose > .loop-stages { max-width: 100%; }
.prose > * + * { margin-top: 0; }
.prose h2 {
  font-size: clamp(1.4rem, 3.4vw, 1.75rem);
  margin: 2.75rem 0 1rem;
}
.prose h3 { font-size: 1.15rem; margin: 2rem 0 0.75rem; }
.prose h2 + h3 { margin-top: 1rem; }
.prose ul, .prose ol { padding-left: 1.4rem; margin: 0 0 1.1rem; }
.prose li { margin-bottom: 0.4rem; }
.prose li::marker { color: var(--amber); }
.prose strong { color: var(--ivory); font-weight: 600; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }
.prose img { margin: 1.5rem 0; }
.prose blockquote {
  margin: 1.5rem 0;
  padding: 1rem 1.25rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  border-radius: 0 4px 4px 0;
}
.prose blockquote > :last-child { margin-bottom: 0; }
.prose table {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  line-height: 1.45;
}
.prose th, .prose td {
  text-align: left;
  vertical-align: top;
  padding: 0.55rem 0.9rem 0.55rem 0;
  border-bottom: 1px solid var(--line);
}
.prose th {
  font-family: var(--label);
  font-weight: 600;
  color: var(--ivory);
  border-bottom-color: var(--amber-dim);
}
.prose td code, .prose th code { white-space: nowrap; }
.prose dl { margin: 0 0 1.25rem; }
.prose dt { font-family: var(--label); font-weight: 600; color: var(--ivory); }
.prose dd { margin: 0.2rem 0 1rem 0; }

/* Code listings, highlighted at build time. */
.listing { margin: 1.5rem 0 1.75rem; }
.listing figcaption {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--soft);
  margin-bottom: 0.4rem;
  overflow-wrap: anywhere;
}
.listing figcaption a { color: var(--soft); }
.listing figcaption a:hover { color: var(--link); }
.listing pre {
  margin: 0;
  padding: 1rem 1.1rem;
  overflow-x: auto;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 0.84rem;
  line-height: 1.55;
  tab-size: 4;
  color: var(--stone);
}
.listing pre:focus-visible { outline-offset: 2px; }
.listing code { background: none; border: 0; padding: 0; font-size: inherit; color: inherit; }
.chroma .line { display: block; }
.chroma .k, .chroma .kd, .chroma .kn, .chroma .kp, .chroma .kr, .chroma .ow { color: var(--syn-keyword); }
.chroma .kt, .chroma .nc, .chroma .nb, .chroma .bp { color: var(--syn-type); }
.chroma .kc, .chroma .no { color: var(--syn-constant); }
.chroma .s, .chroma .sa, .chroma .sb, .chroma .sc, .chroma .dl, .chroma .sd, .chroma .s2,
.chroma .se, .chroma .sh, .chroma .si, .chroma .sx, .chroma .sr, .chroma .s1, .chroma .ss { color: var(--syn-string); }
.chroma .m, .chroma .mb, .chroma .mf, .chroma .mh, .chroma .mi, .chroma .il, .chroma .mo { color: var(--syn-number); }
.chroma .c, .chroma .ch, .chroma .cm, .chroma .c1, .chroma .cs, .chroma .cp, .chroma .cpf { color: var(--syn-comment); }
.chroma .nf, .chroma .fm { color: var(--syn-function); }
.chroma .nt, .chroma .na { color: var(--syn-key); }
.chroma .p, .chroma .o { color: var(--syn-punct); }
.chroma .gp { color: var(--amber); user-select: none; }
.chroma .go { color: var(--stone); }
.chroma .err { color: inherit; background: none; }

/* The four stages, as a cycle. */
.loop-stages {
  list-style: none;
  margin: 1.5rem 0 1.75rem;
  padding: 0;
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 10rem), 1fr));
  counter-reset: stage;
}
.loop-stages li {
  counter-increment: stage;
  position: relative;
  margin: 0;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--amber);
  border-radius: 4px;
  padding: 0.9rem 1rem 0.85rem;
  font-size: 0.95rem;
  line-height: 1.45;
}
.loop-stages li::before {
  content: counter(stage);
  display: inline-grid;
  place-items: center;
  width: 1.6rem;
  height: 1.6rem;
  margin-bottom: 0.5rem;
  border: 2px solid var(--amber);
  border-radius: 50%;
  color: var(--amber);
  font-family: var(--label);
  font-weight: 600;
  font-size: 0.85rem;
}
.loop-stages strong { display: block; font-family: var(--label); margin-bottom: 0.2rem; }
.loop-back {
  font-family: var(--label);
  font-size: 0.9rem;
  color: var(--soft);
  margin-top: -0.75rem;
}

/* A measured result, set apart. */
.result {
  margin: 1.75rem 0;
  padding: 1.25rem 1.4rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  border-radius: 4px;
}
.result .figure {
  font-family: var(--display);
  font-feature-settings: normal;
  font-weight: 600;
  font-size: clamp(2rem, 6vw, 2.6rem);
  line-height: 1;
  color: var(--amber);
  margin-bottom: 0.6rem;
}
.result .figure span {
  font-family: var(--label);
  font-weight: 500;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--stone);
}
.result p:last-child { margin-bottom: 0; }
.result .method, .findings .method {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.2rem 0.9rem;
  margin: 0.9rem 0 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--line);
  font-size: 0.88rem;
  line-height: 1.45;
}
.result .method div, .findings .method div { display: contents; }
.result .method dt, .findings .method dt {
  font-family: var(--label);
  font-weight: 600;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--soft);
  padding-top: 0.15rem;
}
.result .method dd, .findings .method dd { margin: 0; color: var(--stone); }
.findings .method { margin-top: auto; }
.findings .method + .cite { margin-top: 0; }
.result-source {
  font-family: var(--label);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  color: var(--soft);
}
.result-cards {
  display: grid;
  gap: 1rem;
  margin: 1.5rem 0 2rem;
}
.result-cards .result { margin: 0; display: flex; flex-direction: column; }
.result-cards .result-source { margin-top: auto; }
@media (min-width: 60rem) {
  /* Wider than the prose column, as wide as the page's grid. */
  .home-body .result-cards {
    max-width: none;
    grid-template-columns: repeat(3, 1fr);
    width: min(calc(100vw - 2 * var(--gutter) - 1rem), calc(var(--page-max) - 2 * var(--gutter)));
  }
}

/* When to use a design, and when not to. */
.fit {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
  margin: 1.75rem 0;
}
.fit > div {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--amber);
  border-radius: 4px;
  padding: 1rem 1.2rem 0.4rem;
}
.fit > .fit-leave { border-top-color: var(--soft); }
.fit-title {
  font-family: var(--label);
  font-weight: 600;
  color: var(--ivory);
  margin-bottom: 0.5rem;
}
.fit ul { padding-left: 1.1rem; font-size: 0.95rem; line-height: 1.5; }
.fit li { margin-bottom: 0.5rem; }

/* The examples catalog. */
.table-scroll { max-width: 100%; overflow-x: auto; margin: 1.5rem 0; }
.table-scroll:focus-visible { outline: 2px solid var(--amber); outline-offset: 2px; }
.prose .table-scroll table { display: table; margin: 0; overflow: visible; }
.catalog .num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.catalog th[scope="row"] { font-family: inherit; font-weight: 400; white-space: nowrap; border-bottom-color: var(--line); }
.catalog td code { white-space: nowrap; }
.catalog .none { color: var(--soft); }

/* The end of a guide */
.guide-foot { max-width: var(--measure); margin-top: 3rem; }
.book-line {
  padding: 1rem 1.25rem;
  border: 1px solid var(--amber-dim);
  border-radius: 4px;
  background: var(--accent-wash);
  font-size: 0.97rem;
}
.book-line p { margin: 0; }
.pager {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr));
  margin-top: 1.5rem;
}
.pager a {
  display: block;
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--panel);
  color: var(--ivory);
  font-family: var(--label);
  font-weight: 600;
  text-decoration: none;
}
.pager a:hover { border-color: var(--amber-dim); }
.pager span {
  display: block;
  font-weight: 500;
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 0.2rem;
}
.pager-next { text-align: right; }
.pager-prev:only-child { grid-column: 1; }
.pager-next:only-child { grid-column: -2; }

/* Lists of pages */
.cards {
  list-style: none;
  margin: 0 0 2.5rem;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 20rem), 1fr));
}
.cards a {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 1.25rem 1.35rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--amber);
  border-radius: 4px;
  color: var(--stone);
  text-decoration: none;
}
.cards a:hover { border-color: var(--amber-dim); border-top-color: var(--amber); }
.card-kind, .card-cite {
  font-family: var(--label);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber);
}
.card-kind { margin-bottom: 0.35rem; }
.card-title {
  font-family: var(--label);
  font-weight: 600;
  font-size: 1.12rem;
  line-height: 1.3;
  color: var(--ivory);
  margin-bottom: 0.5rem;
}
.cards a:hover .card-title { text-decoration: underline; text-underline-offset: 0.18em; }
.card-desc { font-size: 0.95rem; line-height: 1.5; margin-bottom: 0.75rem; }
.card-cite { margin-top: auto; color: var(--soft); }

/* The home page */
.home-hero { padding: clamp(2.5rem, 7vw, 5rem) 0 clamp(2.5rem, 6vw, 4rem); }
.home-hero .wrap { position: relative; }
.home-hero h1 { font-size: clamp(2.3rem, 7.4vw, 4rem); line-height: 1.08; }
.home-hero .hook { max-width: 36ch; }
.home-body { padding: clamp(2rem, 5vw, 3.5rem) 0 1rem; }
.home-body .prose h2:first-child { margin-top: 0; }
.home-sections { padding: 1.5rem 0 clamp(3.5rem, 8vw, 5.5rem); }
.home-sections h2 { font-size: clamp(1.4rem, 3.4vw, 1.75rem); }
.paths {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 19rem), 1fr));
}
.paths > li {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1.25rem 1.35rem;
}
.paths h3 { font-family: var(--display); font-feature-settings: normal; font-size: 1.3rem; margin-bottom: 0.5rem; }
.paths h3 a { color: var(--ivory); text-decoration: none; }
.paths h3 a:hover { text-decoration: underline; }
.paths p { font-size: 0.95rem; margin-bottom: 0.75rem; }
.paths ul { margin: 0; padding-left: 1.1rem; font-size: 0.95rem; }
.paths ul li { margin-bottom: 0.25rem; }
.paths ul li::marker { color: var(--amber); }
.paths > li > :last-child { margin-bottom: 0; }

/* The glossary: each term a small heading, linkable by its id. */
.glossary .prose h3 { font-size: 1.1rem; margin: 1.75rem 0 0.35rem; }
.glossary .cite-line { display: block; margin-top: 0.3rem; font-family: var(--label); font-size: 0.85rem; color: var(--soft); }
.glossary .letters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.9rem;
  list-style: none;
  padding: 0;
  margin: 0 0 2rem;
  font-family: var(--label);
  font-weight: 600;
}
.glossary .letters li::marker { content: none; }
.glossary .prose h2.letter {
  font-family: var(--display);
  font-size: 1.5rem;
  color: var(--amber);
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.3rem;
  margin-top: 2.75rem;
}
:target { scroll-margin-top: 1rem; }

/* A guide's map of the loop: the four stages, its own marked. */
.stage-map { margin-top: 1.25rem; }
.stage-map-label {
  font-family: var(--label);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--soft);
  margin-bottom: 0.5rem;
}
.stage-map ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 9.5rem), 1fr));
  gap: 0.4rem;
}
.stage-map li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-family: var(--label);
  font-size: 0.86rem;
  color: var(--soft);
}
.stage-map li.on { color: var(--ivory); border-color: var(--amber); background: var(--accent-wash); }
.sm-n {
  flex: none;
  display: inline-grid;
  place-items: center;
  width: 1.3rem;
  height: 1.3rem;
  border: 1.5px solid currentColor;
  border-radius: 50%;
  font-size: 0.72rem;
  font-weight: 600;
}
.stage-map li.on .sm-n { color: var(--amber); }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.prose .loop-stages { padding-left: 0; }
.prose .loop-stages li { margin: 0; }
.prose .loop-stages li::marker { content: none; }

/* The home page's loop figure */
.home-hero-grid { display: grid; gap: 2rem; align-items: center; }
.loop-figure { display: none; width: 100%; max-width: 380px; justify-self: center; overflow: visible; }
@media (min-width: 60rem) {
  .home-hero-grid { grid-template-columns: minmax(0, 1fr) 380px; }
  .loop-figure { display: block; }
}
.lf-ring { fill: none; stroke: var(--line); stroke-width: 1.5; }
.lf-arc { fill: none; stroke: var(--amber); stroke-width: 2; }
.lf-head { fill: var(--amber); }
.lf-node circle { fill: var(--page); stroke: var(--amber); stroke-width: 2; }
.lf-node text { fill: var(--amber); font-family: var(--label); font-weight: 600; font-size: 16px; text-anchor: middle; }
.lf-label { fill: var(--ivory); font-family: var(--label); font-weight: 600; font-size: 17px; text-anchor: middle; }
.lf-center { fill: var(--ivory); font-family: var(--display); font-size: 22px; text-anchor: middle; }
.lf-sub { fill: var(--soft); font-family: var(--label); font-size: 13px; text-anchor: middle; letter-spacing: 0.06em; }
.lf-label.lf-start { text-anchor: start; }
.lf-label.lf-end { text-anchor: end; }
@media (min-width: 60rem) {
  .home-hero-grid { grid-template-columns: minmax(0, 1fr) 440px; }
  .loop-figure { max-width: 440px; }
}
@media (max-width: 71.99rem) {
  .site-nav { -webkit-mask-image: linear-gradient(to right, #000 calc(100% - 2.5rem), transparent); mask-image: linear-gradient(to right, #000 calc(100% - 2.5rem), transparent); }
  .site-nav ul { padding-right: 2.5rem; }
}
@media (max-width: 40rem) {
  .listing pre { font-size: 0.78rem; padding: 0.85rem 0.9rem; }
  .prose table { font-size: 0.9rem; }
}

/* "On this page", beside a guide on wide screens. */
.toc { display: none; }
@media (min-width: 72rem) {
  .guide-body { display: grid; grid-template-columns: minmax(0, 1fr) 14rem; gap: 3rem; align-items: start; }
  .toc {
    display: block;
    position: sticky;
    top: 1.5rem;
    padding-left: 1rem;
    border-left: 1px solid var(--line);
    font-family: var(--label);
    font-size: 0.88rem;
  }
  .toc p {
    font-size: 0.75rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--amber);
    margin-bottom: 0.6rem;
  }
  .toc ol { list-style: none; margin: 0; padding: 0; }
  .toc li { margin-bottom: 0.45rem; line-height: 1.35; }
  .toc a { color: var(--soft); text-decoration: none; }
  .toc a:hover { color: var(--ivory); text-decoration: underline; }
}

/* A guide's closing line about consulting, quieter than the book line. */
.work-line { margin: 0.75rem 0 0; font-size: 0.9rem; color: var(--soft); }

/* Work with me: the services beside the contact form on wide screens. */
.work-grid { display: grid; gap: 2.5rem; align-items: start; }
@media (min-width: 62rem) {
  .work-grid { grid-template-columns: minmax(0, 1fr) 24rem; gap: 4rem; }
  .contact { position: sticky; top: 1.5rem; }
}
.contact {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--amber);
  border-radius: 4px;
  padding: 1.5rem;
}
.contact h2 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.contact > p { font-size: 0.95rem; }
.field { margin-bottom: 1rem; }
.field label {
  display: block;
  margin-bottom: 0.3rem;
  font-family: var(--label);
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--ivory);
}
.field input, .field textarea {
  width: 100%;
  padding: 0.65rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--page);
  color: var(--stone);
  font: inherit;
  font-size: 1rem;
}
.field textarea { resize: vertical; min-height: 8rem; }
.field input:focus-visible, .field textarea:focus-visible { outline: 2px solid var(--amber); outline-offset: 1px; }
/* The honeypot: off screen, not display:none, so bots still fill it. */
.hp { position: absolute; left: -9999px; top: -9999px; width: 1px; height: 1px; overflow: hidden; }
.turnstile { min-height: 65px; margin: 0.25rem 0 1rem; }
.contact .button { width: 100%; }
.contact .button:disabled { opacity: 0.7; cursor: wait; }
.contact-status { min-height: 1.5em; margin: 0.75rem 0 0; font-size: 0.95rem; }
.contact-status.ok { color: var(--syn-string); }
.contact-status.error { color: var(--syn-constant); }
.contact-alt { margin: 1rem 0 0; font-size: 0.92rem; color: var(--soft); }
@media (max-width: 26rem) {
  .contact { padding: 1.25rem 1rem; }
}
.turnstile { max-width: 100%; overflow: hidden; }