/* Joyful Take design system.
   Tokens follow the Apple HIG color, type, spacing, radius, shadow, and
   motion scales. Every color is a semantic custom property with a light and
   a dark value, so the palette can be re-skinned in one place once the owner
   approves a brand direction. */

:root {
  color-scheme: light dark;

  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F2F2F7;
  --color-bg-tertiary: #FFFFFF;

  --color-label-primary: #000000;
  /* The stock HIG value rgba(60,60,67,0.60) measures about 3.4:1 on white,
     which fails WCAG AA for body-size text. Accessibility is mandatory here
     (project rules 27.12 and 28.16), so secondary is darkened to 0.78 alpha,
     about 5.6:1 on white and 5.0:1 on the secondary background. Tertiary is
     reserved for decorative, aria-hidden, or non-text use only. */
  --color-label-secondary: rgba(60, 60, 67, 0.78);
  --color-label-tertiary: rgba(60, 60, 67, 0.30);

  --color-fill-secondary: rgba(120, 120, 128, 0.16);
  --color-fill-tertiary: rgba(118, 118, 128, 0.12);
  --color-fill-quaternary: rgba(116, 116, 128, 0.08);

  --color-separator: rgba(60, 60, 67, 0.29);
  --color-separator-opaque: #C6C6C8;

  /* HIG system blue #007AFF measures about 4.0:1 on white, under the 4.5:1
     AA minimum for body-size link text. Light mode uses #0066CC (about 5.6:1
     on white, 5.0:1 on the secondary background). Dark mode keeps #0A84FF,
     which passes on the dark backgrounds. */
  --color-blue: #0066CC;
  --color-green: #34C759;
  --color-red: #FF3B30;
  --color-orange: #FF9500;
  --color-purple: #AF52DE;
  --color-gray: #8E8E93;
  --color-gray3: #C7C7CC;
  --color-gray5: #E5E5EA;
  --color-gray6: #F2F2F7;

  --mat-nav: rgba(255, 255, 255, 0.72);

  --s1: 4px;  --s2: 8px;  --s3: 12px; --s4: 16px; --s5: 20px;
  --s6: 24px; --s7: 32px; --s8: 40px; --s9: 48px; --s10: 64px;

  --r-xs: 4px; --r-sm: 8px; --r-md: 10px; --r-lg: 14px;
  --r-xl: 20px; --r-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);
  --shadow-lg: 0 8px 24px rgba(0,0,0,.10), 0 4px 8px rgba(0,0,0,.06);

  --ease-standard: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-enter: cubic-bezier(0.0, 0.0, 0.2, 1);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
               Arial, sans-serif, "Apple Color Emoji";
  --font-serif: ui-serif, Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  --measure: 68ch;
  --page-max: 1080px;
  --nav-h: 52px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg-primary: #000000;
    --color-bg-secondary: #1C1C1E;
    --color-bg-tertiary: #1C1C1E;
    --color-label-primary: #FFFFFF;
    --color-label-secondary: rgba(235, 235, 245, 0.72);
    --color-label-tertiary: rgba(235, 235, 245, 0.30);
    --color-fill-secondary: rgba(120, 120, 128, 0.32);
    --color-fill-tertiary: rgba(118, 118, 128, 0.24);
    --color-fill-quaternary: rgba(116, 116, 128, 0.18);
    --color-separator: rgba(84, 84, 88, 0.65);
    --color-separator-opaque: #38383A;
    --color-blue: #0A84FF;
    --color-green: #30D158;
    --color-red: #FF453A;
    --color-orange: #FF9F0A;
    --color-purple: #BF5AF2;
    --color-gray3: #48484A;
    --color-gray5: #2C2C2E;
    --color-gray6: #1C1C1E;
    --mat-nav: rgba(28, 28, 30, 0.72);
    --shadow-sm: 0 1px 3px rgba(0,0,0,.30);
    --shadow-md: 0 4px 12px rgba(0,0,0,.36);
    --shadow-lg: 0 8px 24px rgba(0,0,0,.42);
  }
}

:root[data-theme="dark"] {
  --color-bg-primary: #000000;
  --color-bg-secondary: #1C1C1E;
  --color-bg-tertiary: #1C1C1E;
  --color-label-primary: #FFFFFF;
  --color-label-secondary: rgba(235, 235, 245, 0.72);
  --color-label-tertiary: rgba(235, 235, 245, 0.30);
  --color-fill-secondary: rgba(120, 120, 128, 0.32);
  --color-fill-tertiary: rgba(118, 118, 128, 0.24);
  --color-fill-quaternary: rgba(116, 116, 128, 0.18);
  --color-separator: rgba(84, 84, 88, 0.65);
  --color-separator-opaque: #38383A;
  --color-blue: #0A84FF;
  --color-green: #30D158;
  --color-red: #FF453A;
  --color-orange: #FF9F0A;
  --color-purple: #BF5AF2;
  --color-gray3: #48484A;
  --color-gray5: #2C2C2E;
  --color-gray6: #1C1C1E;
  --mat-nav: rgba(28, 28, 30, 0.72);
  --shadow-sm: 0 1px 3px rgba(0,0,0,.30);
  --shadow-md: 0 4px 12px rgba(0,0,0,.36);
  --shadow-lg: 0 8px 24px rgba(0,0,0,.42);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--color-bg-primary);
  color: var(--color-label-primary);
  font-family: var(--font-sans);
  font-size: 1.0625rem;         /* Body 17px */
  line-height: 1.65;
  letter-spacing: -0.0241em;    /* -0.41px at 17px */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  transition: background-color .2s var(--ease-standard), color .2s var(--ease-standard);
}

/* ---------- Accessibility ---------- */

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 700;
  background: var(--color-blue); color: #FFFFFF;
  padding: var(--s3) var(--s5); border-radius: 0 0 var(--r-md) 0;
  font-weight: 600; text-decoration: none;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--color-blue);
  outline-offset: 2px;
  border-radius: var(--r-xs);
}

.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media (prefers-contrast: more) {
  :root {
    --color-label-secondary: rgba(60, 60, 67, 0.92);
    --color-separator: rgba(60, 60, 67, 0.72);
  }
  :root[data-theme="dark"], :root:not([data-theme="light"]) {
    --color-label-secondary: rgba(235, 235, 245, 0.92);
  }
}

/* ---------- Layout ---------- */

.shell { width: 100%; max-width: var(--page-max); margin: 0 auto; padding: 0 var(--s4); }
@media (min-width: 768px) { .shell { padding: 0 var(--s6); } }
@media (min-width: 1280px) { .shell { padding: 0 var(--s8); } }

.measure { max-width: var(--measure); }

/* ---------- Navigation (thin material, s27.6) ---------- */

.nav {
  position: sticky; top: 0; z-index: 300;
  min-height: var(--nav-h);
  display: flex; align-items: center;
  border-bottom: 0.5px solid var(--color-separator);
  background: var(--color-bg-primary);
}
@supports ((-webkit-backdrop-filter: blur(1px)) or (backdrop-filter: blur(1px))) {
  .nav {
    background: var(--mat-nav);
    -webkit-backdrop-filter: blur(40px) saturate(200%);
    backdrop-filter: blur(40px) saturate(200%);
  }
}
.nav-inner {
  display: flex; align-items: center; gap: var(--s4);
  width: 100%; max-width: var(--page-max); margin: 0 auto;
  padding: var(--s2) var(--s4); min-height: var(--nav-h);
}
@media (min-width: 768px) { .nav-inner { padding: var(--s2) var(--s6); } }
@media (min-width: 1280px) { .nav-inner { padding: var(--s2) var(--s8); } }

.wordmark {
  font-size: 1.0625rem; font-weight: 600; letter-spacing: -0.0241em;
  color: var(--color-label-primary); text-decoration: none;
  display: inline-flex; align-items: center; min-height: 44px;
  white-space: nowrap;
}
.wordmark:hover { color: var(--color-blue); }
.wordmark .wordmark-dot { color: var(--color-blue); }

.nav-links { display: flex; align-items: center; gap: var(--s1); margin-left: auto; }
.nav-link {
  display: inline-flex; align-items: center; min-height: 44px;
  padding: 0 var(--s3); border-radius: var(--r-sm);
  font-size: 0.9375rem; font-weight: 400; letter-spacing: -0.016em;
  color: var(--color-label-secondary); text-decoration: none;
  transition: color .15s var(--ease-standard), background-color .15s var(--ease-standard);
}
.nav-link:hover { color: var(--color-label-primary); background: var(--color-fill-quaternary); }
.nav-link[aria-current="page"] { color: var(--color-label-primary); font-weight: 600; }
@media (max-width: 519px) { .nav-link.optional { display: none; } }

.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; margin-left: var(--s1);
  border: none; border-radius: var(--r-full); cursor: pointer;
  background: transparent; color: var(--color-label-secondary);
  -webkit-appearance: none; appearance: none;
  touch-action: manipulation;
  transition: background-color .15s var(--ease-standard), color .15s var(--ease-standard);
}
.theme-toggle:hover { background: var(--color-fill-tertiary); color: var(--color-label-primary); }
.theme-toggle:active { transform: scale(0.94); }
.theme-toggle svg { width: 20px; height: 20px; }
.theme-toggle .icon-dark { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-dark { display: block; }
:root[data-theme="dark"] .theme-toggle .icon-light { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon-dark { display: block; }
  :root:not([data-theme="light"]) .theme-toggle .icon-light { display: none; }
}

/* ---------- Typography ---------- */

h1, h2, h3 { letter-spacing: -0.02em; margin: 0; }

.masthead { padding: var(--s9) 0 var(--s7); border-bottom: 0.5px solid var(--color-separator); }
.masthead h1 {
  font-size: 2.125rem; font-weight: 700; line-height: 1.206; letter-spacing: 0.0109em;
  margin-bottom: var(--s3);
}
@media (min-width: 768px) { .masthead h1 { font-size: 2.125rem; } }
.masthead .tagline {
  font-size: 1.0625rem; color: var(--color-label-secondary);
  max-width: 52ch; margin: 0;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: var(--s2);
  font-size: 0.8125rem; font-weight: 600; line-height: 1.385;
  letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--color-label-secondary);
}
.eyebrow .dot { width: 6px; height: 6px; border-radius: var(--r-full); background: var(--color-blue); flex: none; }
.eyebrow.is-major .dot { background: var(--color-blue); }
.eyebrow.is-accessory .dot { background: var(--color-orange); }

/* ---------- Article ---------- */

.article-header { padding: var(--s8) 0 var(--s6); }
.article-header h1 {
  font-size: 1.75rem; font-weight: 700; line-height: 1.214; letter-spacing: -0.013em;
  margin: var(--s4) 0 var(--s4); max-width: 22ch;
}
@media (min-width: 735px) { .article-header h1 { font-size: 2.125rem; line-height: 1.18; max-width: 20ch; } }
@media (min-width: 1068px) { .article-header h1 { font-size: 2.5rem; } }

.deck {
  font-size: 1.1875rem; line-height: 1.55; color: var(--color-label-secondary);
  max-width: 56ch; margin: 0 0 var(--s6); letter-spacing: -0.014em;
}

.article-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: var(--s2) var(--s3);
  font-size: 0.8125rem; line-height: 1.385; color: var(--color-label-secondary);
  padding-top: var(--s4); border-top: 0.5px solid var(--color-separator);
}
.article-meta .sep { color: var(--color-label-tertiary); }
.article-meta a { color: var(--color-label-secondary); }
.article-meta a:hover { color: var(--color-blue); }

.prose { max-width: var(--measure); padding: var(--s6) 0 var(--s8); }
.prose > * + * { margin-top: var(--s5); }
.prose p { margin: 0; }
/* The two resets above this line are MORE specific (class + type) than the
   general sibling rule, so they silently zeroed the gaps between consecutive
   paragraphs and around lists. These same-specificity-or-higher rules placed
   later restore the rhythm explicitly. Found by the owner on the live site. */
.prose > * + p { margin-top: var(--s5); }
.prose h2 {
  font-size: 1.375rem; font-weight: 700; line-height: 1.273; letter-spacing: -0.016em;
  margin-top: var(--s8); scroll-margin-top: calc(var(--nav-h) + var(--s4));
}
.prose h3 {
  font-size: 1.25rem; font-weight: 600; line-height: 1.25; letter-spacing: -0.019em;
  margin-top: var(--s7); scroll-margin-top: calc(var(--nav-h) + var(--s4));
}
.prose h2 + p, .prose h3 + p { margin-top: var(--s3); }
.prose a { color: var(--color-blue); text-decoration: underline; text-underline-offset: 0.18em; text-decoration-thickness: 0.06em; }
.prose a:hover { text-decoration-thickness: 0.12em; }
.prose strong { font-weight: 600; }
.prose ul, .prose ol { margin: 0; padding-left: var(--s6); }
.prose > * + ul, .prose > * + ol { margin-top: var(--s5); }
.prose li + li { margin-top: var(--s2); }
.prose li::marker { color: var(--color-label-tertiary); }

.pullquote { margin: var(--s7) 0; padding: 0 0 0 var(--s5); border-left: 3px solid var(--color-blue); }
.pullquote blockquote { margin: 0; }
.pullquote p {
  font-size: 1.25rem; line-height: 1.45; font-weight: 400;
  letter-spacing: -0.019em; color: var(--color-label-primary);
}
.pullquote figcaption {
  margin-top: var(--s3); font-size: 0.8125rem; color: var(--color-label-secondary);
}
.pullquote figcaption a { color: var(--color-label-secondary); }

.notebox {
  background: var(--color-fill-quaternary);
  border-radius: var(--r-lg); padding: var(--s5);
  margin: var(--s6) 0;
}
.notebox p { margin: 0; }
.notebox .notebox-label {
  font-size: 0.8125rem; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--color-label-secondary);
  margin-bottom: var(--s2) !important;
}

.keyfacts {
  background: var(--color-bg-secondary);
  border-radius: var(--r-lg); padding: var(--s5);
  margin: var(--s6) 0;
}
.keyfacts-title {
  font-size: 0.8125rem !important; font-weight: 600 !important; letter-spacing: 0.06em !important;
  text-transform: uppercase; color: var(--color-label-secondary);
  margin: 0 0 var(--s4) !important;
}
.keyfacts dl { margin: 0; display: grid; gap: var(--s3); }
.keyfact { display: grid; grid-template-columns: 1fr; gap: var(--s1); }
@media (min-width: 600px) { .keyfact { grid-template-columns: 11rem 1fr; gap: var(--s4); } }
.keyfact dt { font-size: 0.9375rem; font-weight: 600; color: var(--color-label-secondary); }
.keyfact dd { margin: 0; font-size: 0.9375rem; line-height: 1.5; }

.table-scroll { overflow-x: auto; margin: var(--s6) 0; border-radius: var(--r-lg); }
.table-scroll:focus-visible { outline: 3px solid var(--color-blue); outline-offset: 2px; }
table { border-collapse: collapse; width: 100%; font-size: 0.9375rem; }
caption { text-align: left; font-size: 0.8125rem; color: var(--color-label-secondary); padding-bottom: var(--s3); }
th, td { text-align: left; padding: var(--s3) var(--s4); border-bottom: 0.5px solid var(--color-separator); vertical-align: top; }
th { font-weight: 600; font-size: 0.8125rem; letter-spacing: 0.04em; text-transform: uppercase; color: var(--color-label-secondary); }
tbody tr:last-child td { border-bottom: none; }

/* ---------- References ---------- */

.references { max-width: var(--measure); padding-top: var(--s7); border-top: 0.5px solid var(--color-separator); }
.references h2 {
  font-size: 0.8125rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--color-label-secondary); margin: 0 0 var(--s2);
}
.references .refs-note { font-size: 0.8125rem; color: var(--color-label-secondary); margin: 0 0 var(--s5); }
.references ol { margin: 0; padding-left: var(--s6); display: grid; gap: var(--s4); }
.references li { font-size: 0.9375rem; line-height: 1.5; }
.references li::marker { color: var(--color-label-tertiary); font-variant-numeric: tabular-nums; }
.references a { color: var(--color-blue); text-decoration: underline; text-underline-offset: 0.18em; }
.references .ref-meta { display: block; color: var(--color-label-secondary); font-size: 0.8125rem; margin-top: 2px; }

/* ---------- Related ---------- */

.related { padding: var(--s8) 0 0; }
.related h2 {
  font-size: 0.8125rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--color-label-secondary); margin: 0 0 var(--s4);
}
.related-list { display: grid; gap: var(--s3); margin: 0; padding: 0; list-style: none; }
@media (min-width: 735px) { .related-list { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--s4); } }

.card {
  display: block; padding: var(--s5); border-radius: var(--r-lg);
  background: var(--color-bg-secondary); text-decoration: none; color: inherit;
  box-shadow: var(--shadow-sm); height: 100%;
  transition: transform .2s var(--ease-standard), box-shadow .2s var(--ease-standard);
}
@media (hover: hover) and (pointer: fine) {
  .card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
}
.card:active { transform: scale(0.995); }
.card h3 {
  font-size: 1.0625rem; font-weight: 600; line-height: 1.35; letter-spacing: -0.019em;
  margin: var(--s3) 0 var(--s2);
}
.card p { margin: 0; font-size: 0.9375rem; line-height: 1.5; color: var(--color-label-secondary); }
.card .card-foot { margin-top: var(--s3); font-size: 0.8125rem; color: var(--color-label-secondary); }

/* ---------- Home and edition lists ---------- */

.edition-head { padding: var(--s8) 0 var(--s5); }
.edition-head h2 {
  font-size: 1.375rem; font-weight: 700; line-height: 1.273; margin: var(--s2) 0 var(--s2);
}
.edition-head p { margin: 0; color: var(--color-label-secondary); font-size: 0.9375rem; max-width: 60ch; }

.post-list { list-style: none; margin: 0; padding: 0; }
.post-item { border-top: 0.5px solid var(--color-separator); }
.post-item:first-child { border-top: none; }
.post-link {
  display: block; padding: var(--s6) 0; text-decoration: none; color: inherit;
  transition: background-color .15s var(--ease-standard);
}
@media (hover: hover) and (pointer: fine) {
  .post-link:hover .post-title { color: var(--color-blue); }
}
.post-title {
  font-size: 1.375rem; font-weight: 700; line-height: 1.25; letter-spacing: -0.019em;
  margin: var(--s3) 0 var(--s2); max-width: 26ch;
  transition: color .15s var(--ease-standard);
}
@media (min-width: 735px) { .post-title { font-size: 1.75rem; line-height: 1.21; } }
.post-deck { margin: 0; color: var(--color-label-secondary); font-size: 1.0625rem; max-width: 58ch; }
.post-foot {
  margin-top: var(--s4); font-size: 0.8125rem; color: var(--color-label-secondary);
  display: flex; flex-wrap: wrap; gap: var(--s2) var(--s3); align-items: center;
}
.post-foot .sep { color: var(--color-label-tertiary); }

.post-item.is-accessory .post-title { font-size: 1.25rem; line-height: 1.3; max-width: 34ch; }
@media (min-width: 735px) { .post-item.is-accessory .post-title { font-size: 1.375rem; } }
.post-item.is-accessory .post-link { padding: var(--s5) 0; }

/* ---------- Standing pages ---------- */

.page-header { padding: var(--s9) 0 var(--s5); }
.page-header h1 {
  font-size: 1.75rem; font-weight: 700; line-height: 1.214; margin-bottom: var(--s3);
}
@media (min-width: 735px) { .page-header h1 { font-size: 2.125rem; } }
.page-header .deck { margin-bottom: var(--s3); }
.page-updated { font-size: 0.8125rem; color: var(--color-label-secondary); }

/* ---------- Footer ---------- */

.footer {
  margin-top: var(--s10); padding: var(--s8) 0 var(--s9);
  border-top: 0.5px solid var(--color-separator);
  background: var(--color-bg-secondary);
}
.footer-grid { display: grid; gap: var(--s6); }
@media (min-width: 735px) { .footer-grid { grid-template-columns: 1.4fr 1fr; gap: var(--s8); } }
.footer .about { font-size: 0.9375rem; color: var(--color-label-secondary); max-width: 46ch; margin: var(--s3) 0 0; line-height: 1.55; }
.footer h2 {
  font-size: 0.8125rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--color-label-secondary); margin: 0 0 var(--s3);
}
.footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--s1); }
.footer a {
  color: var(--color-label-secondary); text-decoration: none; font-size: 0.9375rem;
  display: inline-flex; align-items: center; min-height: 32px;
}
.footer a:hover { color: var(--color-blue); text-decoration: underline; }
.footer .colophon {
  margin-top: var(--s8); padding-top: var(--s5); border-top: 0.5px solid var(--color-separator);
  font-size: 0.8125rem; color: var(--color-label-secondary); line-height: 1.55;
}
.footer .colophon p { margin: 0 0 var(--s2); max-width: 76ch; }

/* ---------- Method banner ---------- */

.method-line {
  max-width: var(--measure); margin-top: var(--s7);
  padding: var(--s4) var(--s5); border-radius: var(--r-lg);
  background: var(--color-fill-quaternary);
  font-size: 0.8125rem; line-height: 1.55; color: var(--color-label-secondary);
}
.method-line a { color: var(--color-blue); }

/* ---------- Error page ---------- */

.error-wrap { padding: var(--s10) 0; text-align: left; max-width: 46ch; }
.error-wrap h1 { font-size: 2.125rem; font-weight: 700; margin-bottom: var(--s4); }
.error-wrap p { color: var(--color-label-secondary); margin: 0 0 var(--s6); }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 44px; padding: 0 var(--s5); border-radius: var(--r-full);
  background: var(--color-blue); color: #FFFFFF; text-decoration: none;
  font-size: 1.0625rem; font-weight: 600; letter-spacing: -0.0241em;
  touch-action: manipulation;
  transition: filter .15s var(--ease-standard), transform .15s var(--ease-standard);
}
.btn:hover { filter: brightness(1.08); }
.btn:active { transform: scale(0.97); }