:root {
  --color-ivory: #f7f3ea;
  --color-cream: #efe7d8;
  --color-linen: #e4dac9;
  --color-sage: #a8b09a;
  --color-sage-soft: #e5e9df;
  --color-olive: #5f684c;
  --color-olive-dark: #39412f;
  --color-wood: #8c6f52;
  --color-ink: #2d2c28;
  --color-muted: #6e6a61;
  --color-line: rgba(57, 65, 47, 0.16);
  --shadow-soft: 0 18px 45px rgba(67, 58, 45, 0.08);
  --radius: 1.25rem;
  --content-width: 74rem;
  --reading-width: 45rem;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-sans: Arial, Helvetica, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--color-ivory);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: 1.125rem;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--color-olive-dark); text-underline-offset: 0.2em; }
a:hover { color: var(--color-olive); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--color-wood); outline-offset: 4px; }

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 1000;
  transform: translateY(-160%);
  background: var(--color-olive-dark);
  color: white;
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  text-decoration: none;
}
.skip-link:focus { transform: translateY(0); }

.shell { width: min(calc(100% - 2rem), var(--content-width)); margin-inline: auto; }
.shell--narrow { width: min(calc(100% - 2rem), var(--reading-width)); }

.site-header { border-bottom: 1px solid var(--color-line); background: rgba(247, 243, 234, 0.96); }
.site-header__inner {
  width: min(calc(100% - 2rem), var(--content-width));
  margin-inline: auto;
  min-height: 5.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}
.brand { display: inline-flex; flex-direction: column; text-decoration: none; }
.brand__eyebrow, .chapter-label, .chapter-nav__eyebrow {
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-olive);
  font-weight: 700;
}
.brand__title { font-family: var(--font-serif); font-size: 1.5rem; color: var(--color-olive-dark); }
.top-nav { display: flex; gap: 1.25rem; font-size: 0.95rem; }
.top-nav a { text-decoration: none; }

.hero { padding-bottom: clamp(4rem, 8vw, 7rem); }
.hero__image-wrap { width: min(calc(100% - 2rem), 86rem); margin: 2rem auto 0; }
.hero__image {
  width: 100%;
  max-height: 43rem;
  object-fit: cover;
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}
.hero__content { margin-top: clamp(3rem, 7vw, 6rem); }
h1, h2, h3 { font-family: var(--font-serif); color: var(--color-olive-dark); font-weight: 500; text-wrap: balance; }
h1 { margin: 0.6rem 0 1.2rem; font-size: clamp(2.5rem, 6vw, 4.5rem); line-height: 1.05; }
h2 { margin: 0 0 1.5rem; font-size: clamp(2rem, 4vw, 2.85rem); line-height: 1.16; }
h3 { margin: 0 0 0.7rem; font-size: 1.35rem; line-height: 1.25; }
.hero__subtitle { max-width: 42rem; font-family: var(--font-serif); font-size: clamp(1.25rem, 2vw, 1.6rem); color: var(--color-muted); }
.hero__lead { margin-top: 3rem; padding-left: 1.4rem; border-left: 2px solid var(--color-sage); font-family: var(--font-serif); font-size: clamp(1.25rem, 2vw, 1.55rem); }

.section { padding: clamp(4rem, 8vw, 7rem) 0; }
.section p { margin: 0 0 1.35rem; }
.section--soft { background: var(--color-sage-soft); }
.section--comparison { background: var(--color-cream); }
.section--quiet { background: #efece4; }
.section--closing { background: var(--color-olive-dark); color: #f8f4ea; }
.section--closing h2, .section--closing h3, .section--closing .closing-line, .section--closing .closing-question { color: white; }

.editorial-pause, .principle {
  margin: 3.25rem 0;
  padding: 2.25rem 0 2.25rem 1.5rem;
  border-left: 3px solid var(--color-sage);
  font-family: var(--font-serif);
  font-size: clamp(1.3rem, 2vw, 1.65rem);
  color: var(--color-olive-dark);
}
.editorial-pause p, .principle p { margin-bottom: 0.45rem; }
.statement { margin: 3rem 0 1.5rem !important; font-family: var(--font-serif); font-size: clamp(1.7rem, 3vw, 2.3rem); color: var(--color-olive-dark); }
.statement--small { font-size: clamp(1.45rem, 2.5vw, 1.9rem); }
.note { margin-top: 2rem !important; padding: 1.25rem 1.4rem; background: rgba(229, 233, 223, 0.55); border-left: 3px solid var(--color-sage); }

.editorial-figure { margin: 3rem 0; }
.editorial-figure img { width: 100%; border-radius: var(--radius); box-shadow: var(--shadow-soft); }
.editorial-figure figcaption { margin-top: 1rem; color: var(--color-muted); font-size: 0.95rem; }
.editorial-figure--wide { width: min(100%, 62rem); margin-inline: auto; }

.process-path {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 1rem;
  margin: 3rem 0;
  padding: 0;
  list-style: none;
}
.process-path li {
  position: relative;
  min-height: 7.5rem;
  display: grid;
  place-items: center;
  padding: 1.25rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: rgba(255,255,255,.34);
  text-align: center;
  font-family: var(--font-serif);
  color: var(--color-olive-dark);
}
.process-path li:not(:last-child)::after {
  content: "→";
  position: absolute;
  right: -1rem;
  top: 50%;
  transform: translate(50%, -50%);
  color: var(--color-olive);
  background: var(--color-sage-soft);
  padding: .1rem .25rem;
}

.observation-list { margin: 0; padding: 0; list-style: none; }
.observation-list li { position: relative; padding: .55rem 0 .55rem 1.4rem; }
.observation-list li::before { content: "—"; position: absolute; left: 0; color: var(--color-sage); }
.two-column-list { columns: 2; column-gap: 3rem; margin: 2rem 0 2.5rem; }
.two-column-list li { break-inside: avoid; }
.keywords, .fiber-examples {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin: 2rem 0 2.5rem;
}
.keywords span, .fiber-examples span {
  padding: .5rem .85rem;
  border: 1px solid var(--color-line);
  border-radius: 999px;
  background: rgba(255,255,255,.42);
  font-family: var(--font-serif);
  color: var(--color-olive-dark);
}

.fiber-groups, .trait-grid, .example-cards, .summary-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
  margin: 3rem 0;
}
.fiber-card, .trait-grid article, .example-cards article, .summary-groups article,
.blend-types article, .composition-list article, .composition-examples article, .ore-grid article {
  padding: 1.75rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: rgba(255,255,255,.38);
}
.fiber-card__number { display: block; margin-bottom: 1rem; color: var(--color-olive); font-size: .76rem; font-weight: 700; letter-spacing: .18em; }
.trait-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.comparison, .split-list, .blend-types, .composition-examples {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
  margin: 2.5rem 0 3rem;
}
.comparison__item, .split-list > div {
  padding: 2rem;
  background: rgba(255,255,255,.34);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}
.comparison__label { display: block; margin-bottom: .75rem; color: var(--color-olive); font-size: .78rem; font-weight: 700; letter-spacing: .16em; text-transform: uppercase; }

.composition-list { display: grid; gap: 1rem; margin: 2.5rem 0; }
.composition-list article { display: grid; grid-template-columns: minmax(12rem, .7fr) minmax(0, 1.3fr); gap: 1.5rem; align-items: start; }
.composition-list__value { font-family: var(--font-serif); font-size: 1.4rem; color: var(--color-olive-dark); }
.composition-list p, .composition-examples p { margin-bottom: 0; }
.question-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .8rem; margin: 2rem 0; }
.question-grid span { padding: 1rem 1.15rem; border-left: 3px solid var(--color-sage); background: rgba(255,255,255,.32); font-family: var(--font-serif); color: var(--color-olive-dark); }

.ore-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.25rem; margin: 3rem 0; }
.ore-grid article > span { display: grid; place-items: center; width: 2.4rem; height: 2.4rem; margin-bottom: 1rem; border-radius: 50%; background: var(--color-olive-dark); color: white; font-family: var(--font-serif); }

.summary-groups article { background: rgba(255,255,255,.08); border-color: rgba(255,255,255,.16); }
.summary-groups p { margin-bottom: 0; }
.closing-question { margin: 2rem 0 .25rem !important; font-family: var(--font-serif); font-size: clamp(1.35rem, 2.5vw, 1.8rem); }
.closing-line { margin-top: 3.5rem !important; font-family: var(--font-serif); font-size: clamp(1.7rem, 3vw, 2.3rem); }

.chapter-nav { border-top: 1px solid var(--color-line); background: var(--color-cream); }
.chapter-nav__inner { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 1.5rem; padding-block: 2.5rem; }
.chapter-nav__item { display: inline-flex; flex-direction: column; text-decoration: none; }
.chapter-nav__item--next { text-align: right; }
.chapter-nav__item--disabled { color: var(--color-muted); }
.chapter-nav__title { font-family: var(--font-serif); font-size: 1.2rem; }
.chapter-nav__index { font-size: .95rem; }
.site-footer { padding: 2rem 0; background: #282b24; color: #e9e4d9; text-align: center; font-size: .9rem; }
.back-to-top { position: fixed; right: 1rem; bottom: 1rem; width: 2.75rem; height: 2.75rem; border: 1px solid var(--color-line); border-radius: 50%; background: var(--color-ivory); color: var(--color-olive-dark); box-shadow: var(--shadow-soft); cursor: pointer; }

@media (max-width: 850px) {
  body { font-size: 1.05rem; }
  .site-header__inner { align-items: flex-start; flex-direction: column; padding-block: 1rem; }
  .top-nav { flex-wrap: wrap; }
  .process-path { grid-template-columns: 1fr; }
  .process-path li { min-height: auto; }
  .process-path li:not(:last-child)::after { content: "↓"; right: 50%; top: auto; bottom: -1rem; transform: translate(50%, 50%); }
  .fiber-groups, .trait-grid, .example-cards, .summary-groups, .ore-grid, .comparison, .split-list, .blend-types, .composition-examples { grid-template-columns: 1fr; }
  .composition-list article { grid-template-columns: 1fr; gap: .5rem; }
  .two-column-list { columns: 1; }
  .chapter-nav__inner { grid-template-columns: 1fr; text-align: center; }
  .chapter-nav__item, .chapter-nav__item--next { text-align: center; }
}

@media (max-width: 540px) {
  .shell, .shell--narrow, .site-header__inner, .hero__image-wrap { width: min(calc(100% - 1.25rem), var(--content-width)); }
  .hero__image { min-height: 17rem; object-fit: cover; border-radius: .9rem; }
  .section { padding-block: 3.5rem; }
  .question-grid { grid-template-columns: 1fr; }
  .fiber-card, .trait-grid article, .example-cards article, .summary-groups article, .blend-types article, .composition-list article, .composition-examples article, .ore-grid article, .comparison__item, .split-list > div { padding: 1.35rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}