/* Shared article design for ipso "Short Reads".
   Each article sets its own palette by overriding these variables in a small
   inline <style> block, and supplies its own hero illustration and interactive. */
:root {
  color-scheme: light;
  --night: #120b14;            /* dark bands, buttons */
  --night-2: #1d1220;          /* cards on dark bands */
  --accent: #5a2147;           /* drop cap, quote band, quiz score */
  --accent-2: #3a1230;         /* quote band gradient end */
  --gold: #e2b867;             /* numbers, highlights on dark */
  --gold-2: #c9973f;
  --paper: #f7f1e6;
  --card: #fffaf1;
  --ink: #1d1720;
  --muted: #6b5f66;
  --line: #e4d9c6;
  --label: #c0532f;            /* chapter labels */
  --on-dark: #f1e4d6;
  --on-dark-muted: #bfaebb;
  --hero-ink: #fbefe0;
  --hero-dek: #f3dfd2;
  --hero-bg: linear-gradient(180deg, #160a19 0%, #2e1028 30%, #5a2147 55%, #a24b52 74%, #e08e59 88%, #f3c27a 100%);
  --h1-size: clamp(4rem, 16vw, 11.5rem);
  --display: "Fraunces", Georgia, "Times New Roman", serif;
  --text: "Source Serif 4", Georgia, "Times New Roman", serif;
  --ui: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { background: var(--paper); scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 20px/1.72 var(--text);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }

/* ---------- Reading progress + sticky bar ---------- */
.progress {
  position: fixed; top: 0; left: 0; right: 0; height: 3px; z-index: 50;
  background: linear-gradient(90deg, var(--gold-2), var(--gold));
  transform-origin: 0 50%; transform: scaleX(0);
}
.bar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 40;
  padding: calc(env(safe-area-inset-top, 0px) + 10px) 20px 10px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  background: color-mix(in srgb, var(--night) 86%, transparent);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  color: var(--on-dark); font: 600 13px/1 var(--ui); letter-spacing: .14em; text-transform: uppercase;
  transform: translateY(-110%); transition: transform .35s ease;
}
.bar.show { transform: none; }
.bar .actions { display: flex; gap: 8px; }
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 12px; border-radius: 999px; border: 1px solid color-mix(in srgb, var(--gold) 50%, transparent);
  background: transparent; color: var(--gold); text-decoration: none;
  font: 600 12px/1 var(--ui); letter-spacing: .08em; text-transform: uppercase; cursor: pointer;
}
.chip:hover, .chip:focus-visible { background: color-mix(in srgb, var(--gold) 14%, transparent); outline: none; }

/* ---------- Hero ---------- */
.hero {
  position: relative; min-height: 100vh; min-height: 100svh; overflow: hidden; isolation: isolate;
  display: grid; place-items: start center;
  background: var(--hero-bg);
  color: var(--hero-ink); text-align: center;
}
.hero .art { position: absolute; inset: auto 0 0 0; width: 100%; height: 62%; z-index: -1; }
.hero .art.full { inset: 0; height: 100%; }
.hero .layer { will-change: transform; }
.hero-inner { padding: clamp(80px, 16vh, 160px) 20px 0; max-width: 1000px; }
.eyebrow { font: 600 13px/1 var(--ui); letter-spacing: .36em; text-transform: uppercase; color: var(--gold); }
.hero h1 {
  margin: 18px 0 14px;
  font: 750 var(--h1-size)/.92 var(--display);
  font-variation-settings: "opsz" 144;
  letter-spacing: .02em; text-transform: uppercase;
  text-shadow: 0 6px 40px rgb(0 0 0 / .35);
}
.hero h1 .small { display: block; font-size: .38em; letter-spacing: .3em; font-weight: 600; margin-bottom: .2em; }
.hero .dek {
  max-width: 640px; margin: 0 auto;
  font: italic 400 clamp(1.15rem, 2.6vw, 1.5rem)/1.45 var(--display); color: var(--hero-dek);
}
.meta { margin-top: 22px; font: 600 12px/1 var(--ui); letter-spacing: .2em; text-transform: uppercase; color: color-mix(in srgb, var(--hero-ink) 78%, var(--gold)); }
.meta span + span::before { content: "·"; margin: 0 10px; color: var(--gold); }
.cue {
  position: absolute; left: 50%; bottom: calc(env(safe-area-inset-bottom, 0px) + 22px); translate: -50% 0;
  width: 40px; height: 40px; border-radius: 50%; display: grid; place-items: center;
  border: 1px solid color-mix(in srgb, var(--hero-ink) 45%, transparent); color: var(--hero-ink); text-decoration: none;
  animation: bob 2.4s ease-in-out infinite;
}
@keyframes bob { 50% { transform: translateY(7px); } }
@media (prefers-reduced-motion: reduce) {
  .cue, .hero .anim { animation: none !important; }
}

/* ---------- Article ---------- */
.wrap { max-width: 700px; margin: 0 auto; padding: 0 22px; }
.why {
  position: relative; margin: -64px auto 0; max-width: 760px; z-index: 2;
  background: var(--card); border-radius: 18px; padding: 28px 30px;
  box-shadow: 0 24px 60px -20px rgb(29 23 32 / .35), 0 0 0 1px color-mix(in srgb, var(--gold-2) 25%, transparent);
}
.why .label { font: 700 12px/1 var(--ui); letter-spacing: .2em; text-transform: uppercase; color: var(--label); }
.why p { margin: 10px 0 0; font-size: 1.12rem; }

.chapter { margin-top: 84px; }
.chapter .num { font: 700 12px/1 var(--ui); letter-spacing: .24em; text-transform: uppercase; color: var(--label); }
.chapter h2 {
  margin: 10px 0 18px;
  font: 650 clamp(2rem, 5vw, 2.8rem)/1.08 var(--display); font-variation-settings: "opsz" 96;
  letter-spacing: -.01em; color: var(--night);
}
.chapter h3 { margin: 34px 0 8px; font: 650 1.35rem/1.25 var(--display); color: var(--accent); }
.chapter h3 .dates { font: 400 15px var(--ui); color: var(--muted); margin-left: .4em; }
p { margin: 0 0 20px; }
.lead { font-size: 1.18em; }
.lead::first-letter {
  float: left; margin: .02em .1em 0 0;
  font: 750 4.4em/.78 var(--display); color: var(--accent);
}
strong { font-weight: 600; }
.wrap ul.list { padding-left: 0; list-style: none; margin: 0 0 20px; }
.wrap ul.list li { position: relative; padding-left: 28px; margin-bottom: 12px; }
.wrap ul.list li::before { content: ""; position: absolute; left: 4px; top: .62em; width: 9px; height: 9px; border-radius: 2px; rotate: 45deg; background: var(--label); }

figure { margin: 34px 0; }
.card {
  background: var(--card); border-radius: 16px; padding: 18px;
  box-shadow: 0 0 0 1px var(--line), 0 10px 30px -18px rgb(29 23 32 / .35);
}
.scroll-x { overflow-x: auto; }
.card svg { display: block; width: 100%; height: auto; }
.card.scroll-x svg { min-width: 540px; }
figcaption { margin-top: 12px; font: 400 14px/1.5 var(--ui); color: var(--muted); text-align: center; }
.formula { text-align: center; padding: 22px 18px; }
.formula .eq { font: 400 1.7rem/1.4 var(--display); display: inline-flex; align-items: center; gap: .35em; flex-wrap: wrap; justify-content: center; }
.formula .frac { display: inline-flex; flex-direction: column; text-align: center; }
.formula .frac > span:first-child { border-bottom: 1.5px solid currentColor; padding: 0 .2em; }
.formula .sqrt { border-top: 1.5px solid currentColor; padding: 0 .15em; display: inline-flex; }
.formula .key { display: block; margin-top: 10px; font: 400 14px/1.5 var(--ui); color: var(--muted); }

/* ---------- Full-bleed bands ---------- */
.band { margin-top: 90px; padding: 80px 22px; background: var(--night); color: var(--on-dark); }
.band .inner { max-width: 1040px; margin: 0 auto; }
.band h3 {
  margin: 0 0 6px; text-align: center;
  font: 650 clamp(1.8rem, 4.4vw, 2.6rem)/1.1 var(--display); color: var(--hero-ink);
}
.band .sub { margin: 0 auto 36px; max-width: 560px; text-align: center; font: 400 15px/1.5 var(--ui); color: var(--on-dark-muted); }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 18px; }
.stat { padding: 26px 22px; border-radius: 16px; background: var(--night-2); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--gold) 18%, transparent); }
.stat b { display: block; font: 700 clamp(2.8rem, 6vw, 3.8rem)/1 var(--display); color: var(--gold); font-variant-numeric: tabular-nums; }
.stat b small { font-size: .42em; margin-left: .18em; letter-spacing: .02em; }
.stat > span { display: block; margin-top: 10px; font: 400 15px/1.45 var(--ui); color: color-mix(in srgb, var(--on-dark) 85%, var(--night)); }

/* Interactive "stage" (dark panel used by each article's own demo) */
.lab { display: grid; gap: 20px; }
.stage { width: 100%; height: auto; display: block; border-radius: 16px; background: radial-gradient(ellipse at 50% 30%, color-mix(in srgb, var(--night-2) 80%, white 6%), var(--night)); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--gold) 18%, transparent); }
.steps { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.steps button, .pill {
  font: 600 13px/1 var(--ui); padding: 11px 14px; border-radius: 999px; cursor: pointer;
  color: var(--on-dark); background: var(--night-2); border: 1px solid color-mix(in srgb, var(--gold) 28%, transparent);
}
.steps button[aria-pressed="true"], .pill[aria-pressed="true"], .pill.primary { background: var(--gold); color: var(--night); border-color: var(--gold); }
.steps button:focus-visible, .pill:focus-visible { outline: 2px solid var(--gold); outline-offset: 2px; }
.caption { min-height: 3.2em; margin: 0 auto; max-width: 640px; text-align: center; font: 400 17px/1.55 var(--ui); color: var(--on-dark); }
.legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 18px; font: 400 13px/1 var(--ui); color: var(--on-dark-muted); }
.legend i { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; }
.readout { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px 26px; font: 400 14px/1.3 var(--ui); color: var(--on-dark-muted); text-align: center; }
.readout b { display: block; font: 700 1.7rem/1.1 var(--display); color: var(--gold); font-variant-numeric: tabular-nums; }
.control { display: grid; gap: 8px; max-width: 520px; width: 100%; margin: 0 auto; font: 600 13px/1 var(--ui); color: var(--on-dark-muted); text-align: center; }
.control input[type=range] { width: 100%; accent-color: var(--gold); }

/* Quote */
.quote { background: linear-gradient(135deg, var(--accent), var(--accent-2)); }
.quote blockquote { margin: 0 auto; max-width: 860px; text-align: center; }
.quote blockquote p { margin: 0; font: italic 500 clamp(1.8rem, 5vw, 3.2rem)/1.18 var(--display); color: var(--hero-ink); }
.quote blockquote p::before { content: "“"; display: block; font-size: 2.2em; line-height: .6; color: var(--gold); }
.quote cite { display: block; margin-top: 22px; font: 600 12px/1.4 var(--ui); font-style: normal; letter-spacing: .24em; text-transform: uppercase; color: var(--gold); }

/* Timeline */
.timeline {
  display: grid; grid-auto-flow: column; grid-auto-columns: minmax(220px, 260px); gap: 14px;
  overflow-x: auto; scroll-snap-type: x mandatory; padding: 4px 2px 18px; list-style: none; margin: 0;
}
.timeline li { scroll-snap-align: start; padding: 20px; border-radius: 16px; background: var(--night-2); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--gold) 16%, transparent); }
.timeline li.hi { box-shadow: inset 0 0 0 2px var(--gold); }
.timeline b { display: block; font: 700 1.7rem/1 var(--display); color: var(--gold); }
.timeline span { display: block; margin-top: 10px; font: 400 15px/1.45 var(--ui); color: color-mix(in srgb, var(--on-dark) 88%, var(--night)); }
.hint { text-align: center; font: 400 13px/1 var(--ui); color: var(--on-dark-muted); opacity: .7; margin-top: 4px; }

/* Aside card */
.aside {
  margin: 40px 0; display: grid; grid-template-columns: 64px 1fr; gap: 18px; align-items: start;
  padding: 24px; border-radius: 16px; background: var(--card); box-shadow: 0 0 0 1px var(--line);
}
.aside .icon { width: 64px; height: 56px; color: var(--accent); }
.aside h4 { margin: 0 0 6px; font: 650 1.3rem/1.2 var(--display); }
.aside p { margin: 0; font-size: .95em; }

/* Quiz */
.quiz { margin-top: 90px; }
.quiz .chapter { margin-top: 0; text-align: center; }
.q { margin-top: 22px; padding: 22px; border-radius: 16px; background: var(--card); box-shadow: 0 0 0 1px var(--line); }
.q h4 { margin: 0 0 14px; font: 600 1.1rem/1.35 var(--display); }
.opts { display: grid; gap: 8px; }
.opts button {
  text-align: left; font: 400 16px/1.35 var(--ui); padding: 12px 14px; border-radius: 12px; cursor: pointer;
  background: #fff; color: var(--ink); border: 1px solid var(--line);
}
.opts button:hover:not(:disabled) { border-color: var(--gold-2); }
.opts button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.opts button.right { background: #e9f4e6; border-color: #5d9a52; }
.opts button.wrong { background: #f8e4df; border-color: #c0532f; }
.opts button:disabled { cursor: default; }
.explain { margin: 12px 0 0; font: 400 15px/1.5 var(--ui); color: var(--muted); }
.score { margin-top: 18px; text-align: center; font: 600 15px/1.4 var(--ui); color: var(--accent); min-height: 1.4em; }

/* Come back tomorrow */
.tomorrow {
  margin: 70px auto 0; max-width: 760px; padding: 38px 30px; border-radius: 22px; text-align: center;
  background: radial-gradient(ellipse at 50% 0, var(--accent-2), var(--night)); color: var(--on-dark);
}
.tomorrow h3 { margin: 0 0 8px; font: 650 clamp(1.6rem, 4vw, 2.2rem)/1.15 var(--display); color: var(--hero-ink); }
.tomorrow p { margin: 0 auto 22px; max-width: 480px; font: 400 16px/1.55 var(--ui); color: var(--on-dark-muted); }
.streak { display: inline-block; margin-bottom: 18px; padding: 8px 14px; border-radius: 999px; background: color-mix(in srgb, var(--gold) 14%, transparent); color: var(--gold); font: 600 13px/1 var(--ui); letter-spacing: .06em; }
.btns { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.btn { display: inline-block; padding: 14px 20px; border-radius: 999px; text-decoration: none; cursor: pointer; font: 700 14px/1 var(--ui); letter-spacing: .04em; border: 0; }
.btn.primary { background: var(--gold); color: var(--night); }
.btn.ghost { background: transparent; color: var(--gold); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--gold) 60%, transparent); }
.btn:focus-visible { outline: 2px solid var(--hero-ink); outline-offset: 3px; }

footer.end { margin: 50px 0 0; padding: 28px 22px calc(env(safe-area-inset-bottom, 0px) + 40px); text-align: center; font: 400 14px/1.5 var(--ui); color: var(--muted); }

.reveal { opacity: 0; transform: translateY(18px); transition: opacity .8s ease, transform .8s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

@media (max-width: 560px) {
  body { font-size: 18.5px; }
  .why { margin-top: -48px; padding: 22px; border-radius: 14px; }
  .band { padding: 60px 18px; }
  .aside { grid-template-columns: 1fr; }
  .bar .title { display: none; }
  .cue { display: none; }
}