/* ==========================================================================
   AI 2027 — style clone (Tufte-CSS-inspired)
   Palette:
     background        #fffff8  (warm cream)
     text              #111
     accent (default)  #2a623d  (slowdown green)
     race accent       #8b0000  (race red)
     dull bg / fg      #f0f0f0 / #666
   ========================================================================== */

/* ---- Fonts (self-hosted et-book) ---- */
@font-face {
  font-family: et-book;
  src: url("fonts/et-book-roman.woff") format("woff");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: et-book;
  src: url("fonts/et-book-italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: et-book;
  src: url("fonts/et-book-bold.woff") format("woff");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

/* ---- Base ---- */
:root {
  --vivid-background: #fffff8;
  --vivid-foreground: #000;
  --dull-background: #f0f0f0;
  --dull-foreground: #666;
  --accent: #2a623d;            /* slowdown green */
  --race-background: #8b0000;   /* race red */
  --slowdown-background: #2a623d;
  --line: #ccc;
}

html { font-size: 15px; scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

* { box-sizing: border-box; }

body {
  background-color: var(--vivid-background);
  color: #111;
  font-family: et-book, Palatino, "Palatino Linotype", "Palatino LT STD",
    "Book Antiqua", Georgia, serif;
  margin: 0;
  counter-reset: sidenote-counter;
  -webkit-font-smoothing: antialiased;
}

/* ---- Typography ---- */
h1, h2, h3, h4, h5 { font-weight: 400; line-height: 1; }

h1 { font-size: 68px; margin-top: 0; margin-bottom: 1.5rem; }
h2 { margin-top: 5rem; margin-bottom: 2rem; font-size: 2.2rem; }
h3 { font-size: 1.7rem; margin-top: 2rem; margin-bottom: 1.4rem; font-style: italic; }
h4 { font-size: 1.5rem; margin-top: 1.3rem; margin-bottom: 1.1rem; font-style: italic; }
h5 { font-size: 1.3rem; margin-top: 1.1rem; margin-bottom: 0.9rem; font-style: italic; }

p {
  margin-top: 1.4rem;
  margin-bottom: 1.4rem;
  font-size: 1.4rem;
  line-height: 2rem;
  vertical-align: baseline;
  text-wrap: pretty;
}

p.subtitle {
  font-style: italic;
  margin-top: 1rem;
  margin-bottom: 1rem;
  font-size: 1.8rem;
  line-height: 1;
}

p.author {
  font-style: normal;
  margin-top: 0.25rem;
  margin-bottom: 1rem;
  font-size: 24px;
  line-height: 1.4;
  letter-spacing: -1.2px;
}

p.author a {
  color: inherit;
  text-decoration: none;
}
p.author a:hover { text-decoration: underline; }

p.date {
  font-size: 1.1rem;
  color: var(--dull-foreground);
  margin-top: 1.5rem;
  letter-spacing: 0.02em;
}

p.published {
  font-family: Consolas, Menlo, "Liberation Mono", monospace;
  font-size: 11px;
  line-height: 1.4;
  letter-spacing: 0.03em;
  opacity: 0.55;
  margin: 0 0 0.75rem;
}

ul, ol, dl { font-size: 1.4rem; line-height: 2rem; list-style: revert; }

hr {
  display: block;
  height: 1px;
  width: 100%;
  border: 0;
  border-top: 1px solid var(--line);
  margin: 1em 0;
  padding: 0;
}

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-skip-ink: auto;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 1.5px;
}
a:hover { text-decoration-thickness: from-font; }
a.no-underline { text-decoration: none; }
a.no-underline:hover { text-decoration: underline; }

blockquote { font-size: 1.4rem; }
blockquote p { width: 100%; margin-right: 40px; }
blockquote footer { width: 100%; font-size: 1.1rem; text-align: right; }

span.newthought { font-variant: small-caps; font-size: 1.2em; }

code, pre > code {
  font-family: Consolas, "Liberation Mono", Menlo, Courier, monospace;
  font-size: 1rem;
  line-height: 1.42;
}

/* ---- Sidenotes / margin notes ---- */
.sidenote, .marginnote {
  float: right;
  clear: right;
  margin-right: -42%;
  width: 38%;
  margin-top: 0.3rem;
  margin-bottom: 0;
  font-size: 1.1rem;
  line-height: 1.3;
  vertical-align: baseline;
  position: relative;
}

.sidenote-number { counter-increment: sidenote-counter; }
.sidenote-number:after,
.sidenote:before {
  content: counter(sidenote-counter);
  font-family: et-book, Georgia, serif;
  position: relative;
  vertical-align: baseline;
  font-size: 1rem;
}
.sidenote-number:after { top: -0.5rem; left: 0.1rem; }
.sidenote:before { content: counter(sidenote-counter) " "; top: -0.5rem; }

/* ---- Figures ---- */
figure {
  padding: 0;
  border: 0;
  max-width: 100%;
  margin: 0 0 3em;
  font: inherit;
}
figcaption {
  padding-top: 1.5em;
  top: 3.5em;
  font-size: 1.1rem;
  line-height: 1.6;
  font-style: italic;
  position: relative;
  opacity: 0.654;
}

/* ---- Epigraph ---- */
div.epigraph { margin: 5em 0; }
div.epigraph > blockquote { margin-top: 3em; margin-bottom: 3em; }
div.epigraph > blockquote,
div.epigraph > blockquote > p { font-style: italic; }
div.epigraph > blockquote > footer { font-style: normal; }
div.epigraph > blockquote > footer > cite { font-style: italic; }

/* ==========================================================================
   Layout
   ========================================================================== */
.page {
  display: grid;
  grid-template-columns: minmax(0, 700px) 320px;
  column-gap: 9rem;
  max-width: 1228px;
  margin: 0 6rem 0 auto;
  padding: 0 2rem;
}

/* ---- Header ---- */
.site-header {
  padding: 3rem 0 1rem;
}

.site-title { margin: 0; }
.site-title a { text-decoration: none; }
.site-title a:hover { text-decoration: none; }

.header-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2.5rem;
  font-size: 1.25rem;
  padding-top: 0.4rem;
}
.header-nav a { text-decoration: none; }
.header-nav a:hover { text-decoration: underline; }

.btn-outline {
  border: 1.5px solid #111;
  border-radius: 6px;
  padding: 0.1rem 0.6rem;
  text-decoration: none;
}
.btn-outline:hover { background: var(--dull-background); }

/* Dropdowns (CSS hover / focus-within) */
.dropdown { position: relative; }
.dropdown > button {
  background: none;
  border: none;
  font: inherit;
  color: inherit;
  cursor: pointer;
  padding: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.15rem;
}
.dropdown > button:hover { text-decoration: underline; }
.dropdown .caret { font-size: 0.6em; position: relative; top: -1px; }

.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  min-width: 190px;
  margin-top: 0.25rem;
  background: #fff;
  border: 1px solid #111;
  border-radius: 6px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.12);
  padding: 0.4rem 0;
  display: none;
  z-index: 50;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 0.9rem;
  font-variant: normal;
}
.dropdown:hover .dropdown-menu,
.dropdown:focus-within .dropdown-menu { display: block; }

.dropdown-menu a {
  display: block;
  padding: 0.5rem 1rem;
  text-decoration: none;
  white-space: nowrap;
}
.dropdown-menu a:hover {
  background: var(--accent);
  color: #fff;
}
.dropdown-menu .flag { margin-right: 0.5rem; }
.dropdown-menu .lang-code { float: right; opacity: 0.6; font-size: 0.8rem; }

/* Byline row (date + actions + authors) */
.byline-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 0.5rem;
}
.byline-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-size: 1.3rem;
}
.byline-meta .date { font-weight: 700; }
.meta-sep { width: 1px; height: 16px; background: #111; }
.meta-link { display: inline-flex; align-items: center; gap: 0.4rem; cursor: pointer; }
.meta-link a, .meta-link span { text-decoration: none; }
.meta-link a:hover { text-decoration: underline; }
.byline-authors {
  font-size: 1.3rem;
  letter-spacing: -0.03em;
  text-align: right;
}

/* ---- Article ---- */
.article {
  grid-column: 1;
  padding: 0 0 3rem;
  min-width: 0;
}

.article > section:first-of-type h2 { margin-top: 0.5rem; }

/* ---- Sidebar (sticky, scrollable contents, hidden scrollbar) ---- */
.sidebar {
  grid-column: 2;
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  overflow-y: auto;
  padding: 4rem 0 1.5rem;
  scrollbar-width: none;              /* Firefox */
  -ms-overflow-style: none;           /* Edge / IE */
}
.sidebar::-webkit-scrollbar { display: none; }  /* Chrome / Safari */

.lede { font-size: 1.55rem; }

/* Footnote superscripts */
sup.fn {
  font-size: 0.75rem;
  color: var(--accent);
  position: relative;
  top: -0.5em;
  cursor: pointer;
}
sup.fn a { color: var(--accent); text-decoration: none; }
sup.fn a:hover { text-decoration: underline; }

/* ---- Intro tab boxes ---- */
.tab-boxes { margin-top: 0; margin-bottom: 4rem; }
.tab-tabs { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tab-btn {
  font-family: inherit;
  background: none;
  border: 1.5px solid #111;
  border-radius: 6px;
  padding: 0.25rem 0.6rem;
  font-size: 1.2rem;
  line-height: 1.4;
  text-align: left;
  white-space: nowrap;
  cursor: pointer;
  color: #111;
}
.tab-btn:hover { background: var(--dull-background); }
.tab-btn.active { background: #111; color: #fff; }

.tab-panel {
  display: none;
  margin-top: 0.75rem;
  border: 1.5px solid #111;
  border-radius: 6px;
  padding: 1rem 1.25rem;
  font-size: 1.15rem;
  line-height: 1.4;
}
.tab-panel.open { display: block; }
.tab-panel p { font-size: 1.15rem; line-height: 1.4; margin: 0.5rem 0; }
.tab-panel > :first-child { margin-top: 0; }
.tab-panel > :last-child { margin-bottom: 0; }

/* ---- Scenario chapters ---- */
.chapter { margin-top: 4.5rem; }
.chapter-label {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.95rem;
  color: var(--dull-foreground);
}
.chapter h2 { margin-top: 0.5rem; margin-bottom: 1.5rem; }
.chapter-label + h2 { margin-top: 0.5rem; }

/* ---- Metric callout panels ---- */
.metric-panel {
  border: 1.5px solid #111;
  border-radius: 6px;
  padding: 1.75rem 2rem;
  margin: 2.75rem 0;
}
.metric-panel h4 { margin-top: 0; margin-bottom: 1.5rem; font-style: normal; font-size: 1.3rem; }
.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 1.75rem;
}
.metric .value {
  font-size: 1.9rem;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}
.metric .label { font-size: 1rem; color: var(--dull-foreground); margin-top: 0.4rem; }

/* ---- Scenario endings (slowdown / race) ---- */
.ending { margin-top: 4rem; padding: 1.5rem 2rem; border-radius: 6px; border: 1.5px solid #111; }
.ending.slowdown { --ending-accent: var(--slowdown-background); }
.ending.race { --ending-accent: var(--race-background); }
.ending h3 { margin-top: 0; color: var(--ending-accent); font-style: normal; }
.ending .ending-badge {
  display: inline-block;
  background: var(--ending-accent);
  color: #fff;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.15rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.75rem;
}
.race-accent { color: var(--race-background); }
.slowdown-accent { color: var(--slowdown-background); }

/* ---- Footnotes ---- */
.footnotes { margin-top: 6rem; }
.footnotes h2 { margin-bottom: 2rem; }
.footnotes ol { padding-left: 1.5rem; }
.footnotes li {
  font-size: 1.1rem;
  line-height: 1.6;
  margin-bottom: 0.9rem;
  padding-left: 0.25rem;
}
.footnotes li::marker { color: var(--accent); }
.footnotes a.backlink { text-decoration: none; font-size: 0.85rem; margin-left: 0.4rem; }

/* ---- Footer ---- */
.site-footer {
  margin-top: 4rem;
  padding: 2rem 0 3rem;
  border-top: 1px solid var(--line);
  font-size: 1.05rem;
  color: var(--dull-foreground);
}

/* ---- Subtitle (article title block) ---- */
p.subtitle-secondary {
  font-style: italic;
  margin-top: 0.25rem;
  margin-bottom: 1rem;
  font-size: 1.4rem;
  line-height: 1.35;
  color: var(--dull-foreground);
}

/* ---- Contents / table of contents ---- */
.contents {
  margin: 0;
  border: none;
  border-left: 1px solid var(--line);
  border-radius: 0;
  padding: 0 0 0 1.25rem;
}
.contents h2 { margin: 0 0 1rem; font-size: 1.15rem; color: var(--dull-foreground); }
.contents ol {
  padding-left: 1.25rem;
  margin: 0;
  font-size: 1.02rem;
  line-height: 1.7;
}
.contents li { margin-bottom: 0.3rem; break-inside: avoid; }
.contents a { text-decoration: none; }
.contents a:hover { text-decoration: underline; }

/* ---- Thesis statement (the key bold one-liner) ---- */
p.statement {
  font-size: 1.7rem;
  line-height: 1.45;
  text-align: center;
  font-weight: 700;
  margin: 3rem auto;
  max-width: 90%;
}

/* ---- Lede ---- */
p.lede { font-size: 1.55rem; line-height: 2.1rem; }

/* ---- Tables ---- */
.table-wrapper {
  overflow-x: auto;
  margin: 2rem 0 3rem;
}
table { border-collapse: collapse; width: 100%; }
th, td {
  border: 1px solid #bbb;
  padding: 0.65rem 0.9rem;
  text-align: left;
  vertical-align: top;
}
th {
  background: var(--dull-background);
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1.4;
}
td { font-size: 1.02rem; line-height: 1.5; }

/* ---- References ---- */
.references .ref-category {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 2.75rem 0 1rem;
  line-height: 1.3;
}
.references .ref-category a { text-decoration: underline; }
.references .ref {
  margin: 1.5rem 0;
  padding-left: 2rem;
  border-left: 2px solid var(--line);
}
.references .ref-title { font-size: 1.2rem; line-height: 1.5; }
.references .ref-title a { text-decoration: underline; }
.ref-link {
  display: block;
  margin: 0.4rem 0;
}
.references p { font-size: 1.15rem; line-height: 1.75; margin: 0.55rem 0; }
.references p a { text-decoration: none; }
.references p a:hover { text-decoration: underline; }

/* ---- Author note ---- */
.author-note {
  margin-top: 4rem;
  padding: 1.75rem 2rem;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 1rem;
}
.author-note h3 { font-style: italic; margin-top: 0; }
.author-note p { font-style: italic; font-size: 1.2rem; line-height: 1.8; }

section { scroll-margin-top: 1rem; }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1100px) {
  .sidenote, .marginnote { margin-right: -25%; width: 22%; }
  h1 { font-size: 54px; }
  .page { grid-template-columns: 1fr; max-width: 700px; margin: 0 auto; }
  .article { grid-column: 1; }
  .sidebar {
    display: none;
  }
  .contents { border-left: none; padding-left: 0; }
}

@media (max-width: 860px) {
  .page { padding: 0 1.25rem; }
  .sidenote, .marginnote {
    float: none;
    clear: both;
    margin: 0.5rem 0 0.5rem 1rem;
    width: auto;
    display: block;
    font-size: 1rem;
    line-height: 1.45;
  }
  .site-header { flex-direction: column; }
  .header-nav { gap: 1.25rem; font-size: 1.1rem; }
  h1 { font-size: 46px; }
  .byline-row { flex-direction: column; align-items: flex-start; }
  .byline-authors { text-align: left; }
  p { font-size: 1.25rem; line-height: 1.5; }
}

@media (max-width: 560px) {
  .metric-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .contents ol { columns: 1; }
  p.statement { font-size: 1.4rem; }
}