/* ==========================================================================
   LFE — Learn For Everybody · House stylesheet
   Frozen 2026-07-03 from "Offprint v2", chosen and calibrated by Ashish.
   Visual reference: offprint-v2.html (do not restyle that file; it is the spec).

   The contract: pages express THE LOOK through these tokens only.
   To re-theme every LFE page at once, edit the variables — nothing else.

   House rules distilled from the calibration session:
     1. Serif everywhere — body, UI labels, tabs, even chart ticks.
     2. One accent: ink-blue. No second colour, ever. Neutrals do the rest.
     3. Chrome budget: at most TWO boxed/ruled moments per page
        (e.g. one .panel + one .aside-rule). Everything else is hairlines.
     4. Restrained display voice: weight 600, tight leading, no shouting.
     5. Dark mode is warm charcoal — lamplight, not terminal.
   ========================================================================== */

:root {
  /* -- paper & ink ------------------------------------------------------ */
  --paper:    oklch(99.1% 0.004 96);   /* near-white, a whisper of warmth  */
  --ink:      oklch(24% 0.016 80);     /* warm near-black                  */
  --muted:    oklch(46% 0.014 80);     /* secondary text                   */
  --faint:    oklch(58% 0.012 82);     /* captions, ticks, footers         */
  --hairline: oklch(87.5% 0.009 92);   /* rules; the default "chrome"      */

  /* -- the one accent ---------------------------------------------------- */
  --accent:      oklch(45% 0.125 257); /* ink-blue: fountain pen, not SaaS */
  --accent-soft: oklch(45% 0.125 257 / 0.09);
  --band:        oklch(45% 0.125 257 / 0.06);  /* chart shading, washes    */
  --panel: color-mix(in oklch, var(--paper), oklch(45% 0.125 257) 4.5%);

  /* -- type -------------------------------------------------------------- */
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  /* No sans token. That is deliberate — see house rule 1. */

  /* -- scale ------------------------------------------------------------- */
  --text: 1.06rem;
  --leading: 1.72;
  --display: clamp(2.5rem, 7vw, 3.7rem);
  --h2: clamp(1.5rem, 4vw, 1.9rem);
  --h3: 1.32rem;
  --label: 0.84rem;        /* letterspaced caps labels                     */
  --caption: 0.86rem;
  --measure: 62ch;
  --page-max: 720px;       /* single-column reading measure                */
}

:root[data-theme="dark"] {
  --paper:    oklch(22.5% 0.012 80);   /* warm charcoal, not blue-black    */
  --ink:      oklch(90% 0.013 90);
  --muted:    oklch(70% 0.013 88);
  --faint:    oklch(58% 0.012 85);
  --hairline: oklch(35% 0.013 82);
  --accent:      oklch(73% 0.08 252);  /* same blue, lifted for dark paper */
  --accent-soft: oklch(73% 0.08 252 / 0.13);
  --band:        oklch(73% 0.08 252 / 0.07);
  --panel: color-mix(in oklch, var(--paper), oklch(73% 0.08 252) 6%);
}

/* ==========================================================================
   Base
   ========================================================================== */

* { box-sizing: border-box; }

html { color-scheme: light; }
html[data-theme="dark"] { color-scheme: dark; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: var(--text);
  line-height: var(--leading);
  transition: background 300ms ease, color 300ms ease;
}

@media (prefers-reduced-motion: reduce) {
  body { transition: none; }
}

a { color: inherit; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.page {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: 0 24px 6rem;
}

h1 {
  margin: 0;
  font-size: var(--display);
  font-weight: 600;
  line-height: 1.06;
  letter-spacing: -0.01em;
  max-width: 14ch;
}

h2 {
  margin: 0 0 1.4rem;
  font-size: var(--h2);
  font-weight: 600;
  line-height: 1.22;
  max-width: 24ch;
}

h3 {
  margin: 0.6rem 0 0.8rem;
  font-size: var(--h3);
  font-weight: 600;
  line-height: 1.3;
}

/* ==========================================================================
   Recurring parts (each maps 1:1 to a block in offprint-v2.html)
   ========================================================================== */

/* -- identity strip ------------------------------------------------------ */
.lfe-strip {
  padding: 1.1rem 0 0.85rem;
  border-bottom: 1px solid var(--hairline);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  display: flex;
  align-items: baseline;
  gap: 1.2rem;
}
.lfe-strip .domain {
  margin-left: auto;
  letter-spacing: 0.08em;
  color: var(--faint);
  font-weight: 400;
}

.lfe-strip a {
  color: inherit;
  text-decoration: none;
}
.lfe-strip a:hover { color: var(--accent); }

.theme-toggle {
  font: inherit;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: none;
  border: none;
  border-bottom: 1px solid var(--hairline);
  color: var(--faint);
  padding: 0 0 2px;
  cursor: pointer;
}
.theme-toggle:hover { color: var(--accent); border-bottom-color: var(--accent); }

/* -- house header, bar 2: sticky section nav with scroll-spy --------------
   The house header is TWO bars: the .lfe-strip above (identity: wordmark →
   LFE home, link out to econforeverybody.com, theme toggle) scrolls away;
   this nav sticks and shows where you are. Markup:
     <nav class="lfe-nav"><div class="lfe-nav-row"> …hash links… </div></nav>
   (put the row inside the page's own width container on wide layouts).
   lfe-theme.js marks the section in view with .is-current — darker, bolder.
   Tabbed pieces (e.g. macro/india-growth) use their tabbar as bar 2 instead. */
.lfe-nav {
  position: sticky;
  top: 0;
  z-index: 30;
  background: var(--paper);
  border-bottom: 1px solid var(--hairline);
}
.lfe-nav-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 1.3rem;
  padding: 0.72rem 0;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}
.lfe-nav a {
  color: var(--faint);
  text-decoration: none;
  padding-bottom: 2px;
}
.lfe-nav a:hover { color: var(--ink); }
.lfe-nav a.is-current {
  color: var(--ink);
  font-weight: 700;
  box-shadow: inset 0 -2px 0 var(--accent);
}

/* keep anchored sections clear of the sticky nav */
html { scroll-padding-top: 3.6rem; }

/* -- masthead ------------------------------------------------------------ */
.masthead { padding: 4.5rem 0 0; }

.eyebrow,
.kicker {
  margin: 0 0 1.1rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.17em;
  text-transform: uppercase;
  color: var(--accent);
}
.eyebrow { margin-bottom: 1.4rem; }

.dek {
  margin: 1.6rem 0 0;
  max-width: 52ch;
  font-size: 1.22rem;
  line-height: 1.55;
  color: var(--muted);
  font-style: italic;
}

.keyline {
  margin: 2.6rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid var(--hairline);
  font-size: 0.92rem;
  letter-spacing: 0.02em;
  color: var(--muted);
}
.keyline strong {
  font-size: 1.32rem;
  font-weight: 600;
  color: var(--ink);
  padding: 0 0.15rem;
}

/* -- tabs ---------------------------------------------------------------- */
.tabs {
  margin-top: 3.2rem;
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  padding: 0.8rem 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1.7rem;
  font-size: var(--label);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}
.tabs a { text-decoration: none; color: var(--faint); padding-bottom: 3px; }
.tabs a:hover { color: var(--ink); }
.tabs a.active { color: var(--ink); border-bottom: 2px solid var(--accent); }
.tabs .math-link { margin-left: auto; color: var(--accent); }

/* -- chapters ------------------------------------------------------------ */
.chapter { padding-top: 4rem; }
.chapter p:not(.kicker) { max-width: var(--measure); margin: 1.1rem 0 0; }

/* -- chart (SVG styled via tokens so dark mode flips it) ------------------ */
.chart { margin: 3.4rem 0 0; }
.chart svg { display: block; width: 100%; height: auto; }

.grid-line       { stroke: var(--hairline); stroke-width: 1; }
.axis-line       { stroke: var(--faint); stroke-width: 1; }
.line-primary    { stroke: var(--accent); stroke-width: 1.9; fill: none; }
.line-reference  { stroke: var(--muted); stroke-width: 1.4; stroke-dasharray: 6 5; fill: none; }
.clock-band      { fill: var(--band); }
.marker-rule     { stroke: var(--accent); stroke-width: 1; stroke-dasharray: 2 4; }
.marker-dot      { fill: var(--accent); stroke: var(--paper); stroke-width: 2.5; }
.tick-label      { fill: var(--faint); font-family: var(--serif); font-size: 12px; }
.chart-annot     { fill: var(--ink); font-family: var(--serif); font-size: 14.5px; font-style: italic; }
.chart-annot-sub { fill: var(--faint); font-family: var(--serif); font-size: 11.5px; font-style: italic; }
.legend-label    { fill: var(--muted); font-family: var(--serif); font-size: 12px; }

figcaption {
  margin-top: 0.9rem;
  font-size: var(--caption);
  font-style: italic;
  line-height: 1.6;
  color: var(--faint);
  max-width: 60ch;
}

/* -- controls ------------------------------------------------------------ */
.controls {
  margin-top: 3.2rem;
  border-top: 1px solid var(--hairline);
  padding-top: 1.8rem;
  display: grid;
  gap: 1.35rem;
  max-width: 30rem;
}
.control {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 0.3rem 1rem;
}
.control span {
  font-size: var(--label);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.control output { font-size: 1.14rem; font-weight: 600; font-variant-numeric: tabular-nums; }
.control input[type="range"] {
  grid-column: 1 / -1;
  width: 100%;
  height: 18px;
  accent-color: var(--accent);
}

/* -- the chrome budget: two deliberate moments --------------------------- */
/* Moment 1: a tinted panel. Use once per page (math, key result, aside). */
.panel {
  background: var(--panel);
  border: 1px solid var(--hairline);
  padding: 1.8rem 1.9rem 2rem;
}

/* Moment 2: a quiet left rule. Use once per page (question, pull-aside). */
.aside-rule {
  border-left: 2px solid var(--accent);
  padding-left: 1.4rem;
}
.aside-rule p { margin: 0; color: var(--muted); }

/* -- formula ------------------------------------------------------------- */
.formula {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  font-size: 1.3rem;
  font-weight: 500;
  flex-wrap: wrap;
}
.fraction { display: inline-grid; text-align: center; gap: 0.2rem; }
.fraction .num { border-bottom: 1px solid var(--ink); padding-bottom: 0.22rem; }
sub { font-size: 0.62em; }

.defs { margin: 1.9rem 0 0; display: grid; gap: 0.7rem; }
.defs div { display: grid; grid-template-columns: 5.5rem 1fr; gap: 1rem; align-items: baseline; }
.defs dt { font-weight: 600; font-size: 1.05rem; }
.defs dd { margin: 0; color: var(--muted); font-size: 0.98rem; }

/* -- footer --------------------------------------------------------------- */
.lfe-footer {
  margin-top: 5.5rem;
  border-top: 1px solid var(--hairline);
  padding-top: 1.2rem;
  font-size: var(--label);
  letter-spacing: 0.04em;
  color: var(--faint);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.lfe-footer .ethos { font-style: italic; font-size: 0.95rem; }

/* -- small screens -------------------------------------------------------- */
@media (max-width: 560px) {
  .tabs { gap: 1rem; }
  .tabs .math-link { margin-left: 0; }
  .defs div { grid-template-columns: 4rem 1fr; }
  .lfe-strip { flex-wrap: wrap; gap: 0.6rem; }
  .lfe-strip .domain { margin-left: 0; }
}