/* catspeptides.com - mobile-first components, ck- prefix.
   Paper, ink and one highlighter. Base styles first, then one component per block,
   each widening at min-width breakpoints only. */

:root {
  --paper: #FDFBF7;
  --paper-quiet: #F5F5F5;
  --ink: #1A1A1A;
  --pencil: #4A4A4A;
  --hairline: #E0E0E0;
  --highlighter: #FFFF00;
  --unit: 8px;
  --radius: 8px;
  --shadow: 0 2px 12px rgba(26, 26, 26, 0.05);
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --measure: 68ch;
  --gap-major: clamp(4rem, 8vw, 8rem);
  --gap-section: clamp(3rem, 6vw, 5rem);
  color-scheme: light;
}

/* ---------- base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.6;
  overflow-wrap: break-word;
}
h1, h2, h3 { line-height: 1.2; margin: 0; }
p, ul, ol { margin: 0; }
img { display: block; max-width: 100%; height: auto; }
a { color: var(--ink); text-decoration-thickness: 1px; text-underline-offset: 0.2em; }
a:hover { background-color: var(--paper-quiet); }
a:focus-visible, summary:focus-visible, select:focus-visible, [tabindex="-1"]:focus-visible {
  outline: 3px solid var(--ink);
  outline-offset: 3px;
}
[tabindex="-1"]:focus:not(:focus-visible) { outline: none; }

/* ---------- ck-skip ---------- */
.ck-skip {
  position: absolute;
  left: 0.5rem;
  top: -5rem;
  z-index: 10;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 1rem;
  background-color: var(--paper);
  border: 1px solid var(--ink);
  border-radius: var(--radius);
}
.ck-skip:focus { top: 0.5rem; }

/* ---------- ck-shell ---------- */
.ck-shell {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* ---------- ck-masthead ---------- */
.ck-masthead {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1.25rem 0 1rem;
  border-bottom: 1px solid var(--hairline);
}
.ck-masthead__name {
  display: inline-flex;
  align-items: center;
  align-self: flex-start;
  min-height: 44px;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
  text-decoration: none;
}
.ck-masthead__tag { color: var(--pencil); font-size: 1rem; }

/* ---------- ck-layout ---------- */
.ck-layout { display: block; }

/* ---------- ck-index (side index) ---------- */
.ck-index {
  padding: 1rem 0 1.25rem;
  border-bottom: 1px solid var(--hairline);
  counter-reset: chapter;
}
.ck-index__label {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
  margin-bottom: 0.5rem;
}
.ck-index__chapters, .ck-index__sections {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.25rem;
}
.ck-index__chapters { counter-reset: chapter; }
.ck-index__link {
  counter-increment: chapter;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-height: 48px;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background-color: var(--paper);
  text-decoration: none;
  font-weight: 600;
}
.ck-index__link::before {
  content: counter(chapter, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--pencil);
}
.ck-index__link[aria-current="page"] {
  border-color: var(--ink);
  box-shadow: inset 4px 0 0 var(--ink);
}
.ck-index__onpage { margin-top: 1rem; }
.ck-index__summary {
  display: flex;
  align-items: center;
  min-height: 44px;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
}
.ck-index__sublink {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0.375rem 0.75rem;
  border-left: 2px solid var(--hairline);
  text-decoration: none;
  font-size: 1rem;
  line-height: 1.35;
}
.ck-index__sublink[aria-current="location"] { border-left-color: var(--ink); font-weight: 600; }

@media (min-width: 30rem) {
  .ck-index__chapters { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .ck-index__chapters--solo { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- ck-jump (built by js/jump.js) ---------- */
.ck-jump {
  position: sticky;
  top: 0;
  z-index: 5;
  display: grid;
  gap: 0.25rem;
  margin: 0 -1rem;
  padding: 0.5rem 1rem 0.75rem;
  background-color: var(--paper);
  border-bottom: 1px solid var(--hairline);
}
.ck-jump[hidden] { display: none; }
.ck-jump__label {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
}
.ck-jump__select {
  width: 100%;
  min-height: 48px;
  padding: 0.5rem 0.75rem;
  font: inherit;
  font-size: 1rem;
  color: var(--ink);
  background-color: var(--paper);
  border: 1px solid var(--ink);
  border-radius: var(--radius);
}

/* ---------- ck-main ---------- */
.ck-main { padding: 1.5rem 0 0; min-width: 0; }

/* ---------- ck-hero ---------- */
.ck-hero {
  display: grid;
  gap: 1.5rem;
  align-items: center;
}
.ck-hero__text { display: grid; gap: 1rem; }
.ck-kicker {
  font-family: var(--mono);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--pencil);
}
.ck-hero__title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.08;
}
.ck-hero__lede { font-size: 1.1875rem; max-width: var(--measure); }
.ck-hero__media { margin: 0; }
.ck-hero__img, .ck-row__img {
  width: 100%;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background-color: var(--paper-quiet);
}
@media (min-width: 48rem) {
  .ck-hero { grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 2.5rem; }
  .ck-hero--solo { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- ck-opener (chapter opener) ---------- */
.ck-opener {
  margin-top: 2.5rem;
  padding: 1rem 0 1rem 1.25rem;
  border-left: 4px solid var(--ink);
  font-size: 1.1875rem;
  max-width: var(--measure);
}

/* ---------- ck-section ---------- */
.ck-section { margin-top: var(--gap-section); }
.ck-section__title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
  max-width: var(--measure);
  scroll-margin-top: 6rem;
}
.ck-prose { max-width: var(--measure); margin-top: 1rem; }
.ck-section__title + .ck-prose { margin-top: 0; }

.ck-section--alert {
  padding: 1.25rem;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background-color: var(--paper);
  box-shadow: var(--shadow);
}
.ck-highlight {
  background-color: var(--highlighter);
  padding: 0 0.25em;
  -webkit-box-decoration-break: clone;
  box-decoration-break: clone;
}

/* ---------- ck-row (zig-zag text and image) ---------- */
.ck-row { display: grid; gap: 1.5rem; }
.ck-row__media { margin: 0; }
@media (min-width: 48rem) {
  .ck-row { grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 2.5rem; align-items: start; }
  .ck-row--flip .ck-row__media { order: -1; }
  .ck-row--flip { grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr); }
}

/* ---------- ck-check (checklist) ---------- */
.ck-check {
  list-style: none;
  padding: 0;
  margin-top: 1rem;
  max-width: var(--measure);
  display: grid;
  gap: 0.75rem;
}
.ck-check__item { position: relative; padding-left: 2.25rem; }
.ck-check__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.2em;
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--pencil);
  border-radius: 4px;
  background-color: var(--paper);
}

/* ---------- ck-questions ---------- */
.ck-questions {
  list-style: none;
  padding: 0;
  margin-top: 1rem;
  max-width: var(--measure);
  display: grid;
  gap: 1rem;
  counter-reset: question;
}
.ck-questions__item {
  counter-increment: question;
  position: relative;
  padding: 1rem 1rem 1rem 3.25rem;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background-color: var(--paper);
  box-shadow: var(--shadow);
}
.ck-questions__item::before {
  content: counter(question);
  position: absolute;
  left: 1rem;
  top: 1rem;
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 0.8125rem;
  border: 1px solid var(--ink);
  border-radius: 4px;
}
.ck-questions__ask { font-weight: 700; }
.ck-questions__why { margin-top: 0.5rem; color: var(--pencil); }

/* ---------- ck-faq ---------- */
.ck-faq { display: grid; gap: 1.5rem; max-width: var(--measure); }
.ck-faq__item { padding-top: 1.25rem; border-top: 1px solid var(--hairline); }
.ck-faq__q { font-size: 1.1875rem; font-weight: 700; }
.ck-faq__item .ck-prose { margin-top: 0.5rem; }

/* ---------- ck-cards (evidence cards) ---------- */
.ck-cards {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 1.5rem;
}
.ck-evidence {
  display: grid;
  gap: 1rem;
  padding: 1.25rem;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background-color: var(--paper);
  box-shadow: var(--shadow);
}
.ck-evidence__head { display: grid; gap: 0.5rem; align-content: start; }
.ck-evidence__body { display: grid; gap: 0.75rem; align-content: start; }
.ck-evidence__tag {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
}
.ck-evidence__claim { font-size: 1.25rem; font-weight: 700; }
.ck-evidence__checked { font-family: var(--mono); font-size: 1rem; color: var(--pencil); }
.ck-grade {
  justify-self: start;
  padding: 0.25rem 0.625rem;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  font-family: var(--mono);
  font-size: 0.875rem;
  font-weight: 500;
}
.ck-grade--warn { background-color: var(--highlighter); }
@media (min-width: 48rem) {
  .ck-evidence { grid-template-columns: minmax(0, 15rem) minmax(0, 1fr); gap: 2rem; padding: 1.5rem; }
}

/* ---------- ck-sourcelist ---------- */
.ck-sourcebox { margin-top: 1.25rem; max-width: var(--measure); }
.ck-sourcebox__label {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
}
.ck-sourcelist { list-style: none; padding: 0; display: grid; gap: 0.125rem; }
.ck-source {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0.375rem 0;
  font-size: 1rem;
  line-height: 1.35;
}
.ck-source::after { content: "\2197"; margin-left: 0.4em; font-size: 0.875em; text-decoration: none; }

/* ---------- ck-recap ---------- */
.ck-recap {
  margin-top: var(--gap-major);
  padding: 1.25rem 1.25rem 1.5rem;
  max-width: calc(var(--measure) + 2.5rem);
  background-color: var(--paper-quiet);
  border: 1px solid var(--hairline);
  border-left: 4px solid var(--ink);
  border-radius: var(--radius);
}
.ck-recap__title {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  scroll-margin-top: 6rem;
}
.ck-recap__list { margin-top: 0.75rem; padding-left: 1.25rem; display: grid; gap: 0.5rem; }

/* ---------- ck-next ---------- */
.ck-next {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 56px;
  margin-top: 2rem;
  max-width: calc(var(--measure) + 2.5rem);
  padding: 0.75rem 1.25rem;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  font-weight: 700;
  text-decoration: none;
}
.ck-next::after { content: "\2192"; font-family: var(--mono); }

/* ---------- ck-footer ---------- */
.ck-footer {
  margin-top: var(--gap-major);
  padding: 1.5rem 0 2.5rem;
  border-top: 1px solid var(--hairline);
  display: grid;
  gap: 1rem;
}
.ck-footer__line { font-size: 1rem; color: var(--pencil); max-width: var(--measure); }
.ck-footer__links { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 0.25rem 1.5rem; }
.ck-footer__link { display: inline-flex; align-items: center; min-height: 44px; font-size: 1rem; }

/* ---------- wide screens: the side index ---------- */
@media (min-width: 48rem) {
  .ck-shell { padding: 0 1.5rem; }
  .ck-jump { margin: 0 -1.5rem; padding-left: 1.5rem; padding-right: 1.5rem; }
}
@media (min-width: 64rem) {
  body { font-size: 1.0625rem; }
  .ck-layout {
    display: grid;
    grid-template-columns: 15rem minmax(0, 1fr);
    gap: 4rem;
    align-items: start;
  }
  .ck-index {
    position: sticky;
    top: 1.5rem;
    max-height: calc(100vh - 3rem);
    overflow-y: auto;
    padding: 1.5rem 0.25rem 1.5rem 0;
    border-bottom: 0;
  }
  .ck-index__chapters { grid-template-columns: minmax(0, 1fr); }
  .ck-jump, .ck-jump:not([hidden]) { display: none; }
  .ck-main { padding-top: 2.5rem; }
  .ck-hero__title { font-size: clamp(2.5rem, 4.2vw, 4rem); }
}

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

/* ---------- print: a clean sheet for the exam room ---------- */
@media print {
  body { background-color: #fff; font-size: 12pt; }
  .ck-index, .ck-jump, .ck-next, .ck-footer nav, .ck-skip, .ck-hero__media, .ck-row__media { display: none !important; }
  .ck-layout, .ck-hero, .ck-row, .ck-evidence { display: block; }
  .ck-section { margin-top: 1.5rem; break-inside: avoid-page; }
  .ck-questions__item, .ck-evidence, .ck-recap { box-shadow: none; break-inside: avoid; }
  .ck-source::after { content: " (" attr(href) ")"; font-size: 9pt; }
}