/* Plainledger lesson styles.
   Layout: rail | reading column | margin notes. The ledger is the one loud object; everything else stays quiet.
   Motif: a double rule means "the bottom line" (header, ledger totals). It is used nowhere else. */

@font-face {
  font-family: "Literata";
  src: url("fonts/literata-latin-normal.woff2") format("woff2");
  font-weight: 200 900; font-style: normal; font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Literata";
  src: url("fonts/literata-latin-italic.woff2") format("woff2");
  font-weight: 200 900; font-style: italic; font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Literata";
  src: url("fonts/literata-rupee.woff2") format("woff2");
  font-weight: 200 900; font-style: normal; font-display: swap;
  unicode-range: U+20B9;
}

:root {
  --paper: #e9f0e5;        /* ledger-pad green, the page */
  --sheet: #f8faf4;        /* the ruled sheet the figures sit on */
  --ink: #14233a;
  --ink-2: #3c4a5f;
  --ink-3: #5a687c;
  --rule: #bccfb8;         /* ledger line */
  --rule-strong: #8fab8b;
  --margin-line: #d8a4a0;  /* the red margin of a ledger page */
  --red: #ab2a24;          /* red pen: negatives */
  --green: #2b684b;
  --flash: #f1e49a;
  --shadow: rgba(20, 35, 58, 0.28);

  --font: "Literata", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;

  --rail: 12.5rem;
  --main: 36rem;
  --note: 15rem;
  --gap: 2.5rem;
  --row: 2rem;             /* one ledger line */
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0e1715; --sheet: #15211e; --ink: #e5ede2; --ink-2: #bac7bc; --ink-3: #93a497;
    --rule: #2a3f37; --rule-strong: #46665a; --margin-line: #6b3f3d; --red: #ff9188; --green: #86d6a8;
    --flash: #4d4721; --shadow: rgba(0, 0, 0, 0.6);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0e1715; --sheet: #15211e; --ink: #e5ede2; --ink-2: #bac7bc; --ink-3: #93a497;
  --rule: #2a3f37; --rule-strong: #46665a; --margin-line: #6b3f3d; --red: #ff9188; --green: #86d6a8;
  --flash: #4d4721; --shadow: rgba(0, 0, 0, 0.6);
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.65;
  font-optical-sizing: auto;
  text-rendering: optimizeLegibility;
  -webkit-text-size-adjust: 100%;
}

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

.skip {
  position: absolute; left: 1rem; top: -4rem; z-index: 20;
  background: var(--ink); color: var(--paper); padding: .5rem 1rem; text-decoration: none;
}
.skip:focus { top: 1rem; }

a { color: var(--ink); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; text-decoration-color: var(--rule-strong); }
a:hover { text-decoration-thickness: 2px; text-decoration-color: var(--ink); }

.wrap {
  width: 100%; max-width: 78rem; margin-inline: auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}

/* ---------- Site header ---------- */
.site-header { border-bottom: 3px double var(--ink); }
.site-header .wrap { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: .5rem 2rem; padding-block: 1.1rem .9rem; }
.wordmark { font-size: 1.35rem; font-weight: 700; letter-spacing: -0.015em; text-decoration: none; }
.wordmark:hover { text-decoration: none; }
.site-nav ul { display: flex; flex-wrap: wrap; gap: .25rem 1.6rem; margin: 0; padding: 0; list-style: none; }
.site-nav a { color: var(--ink-2); text-decoration: none; padding-block: .2rem; border-bottom: 2px solid transparent; font-size: .975rem; }
.site-nav a:hover { color: var(--ink); border-bottom-color: var(--rule-strong); }
.site-nav a[aria-current="page"] { color: var(--ink); font-weight: 600; border-bottom-color: var(--ink); }

/* ---------- Page shell ---------- */
.shell { display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); column-gap: var(--gap); padding-block: 2rem 4rem; }

.rail { position: sticky; top: 1.5rem; align-self: start; font-size: .9375rem; line-height: 1.4; }
.rail summary { font-weight: 700; list-style: none; cursor: default; margin-bottom: .6rem; }
.rail summary::-webkit-details-marker { display: none; }
.rail ol { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--rule-strong); }
.rail a { display: block; padding: .38rem 0 .38rem .9rem; margin-left: -1px; border-left: 2px solid transparent; color: var(--ink-2); text-decoration: none; }
.rail a:hover { color: var(--ink); }
.rail a[aria-current="true"] { color: var(--ink); font-weight: 600; border-left-color: var(--ink); }

/* The article is a two-column grid: reading column and margin notes. */
.article { display: grid; grid-template-columns: minmax(0, var(--main)) minmax(0, var(--note)); column-gap: var(--gap); align-content: start; }
.article > * { grid-column: 1; min-width: 0; }
.article > .wide, .article > .hero { grid-column: 1 / -1; }
.article > .blk { grid-column: 1 / -1; display: grid; grid-template-columns: subgrid; }
@supports not (grid-template-columns: subgrid) {
  .article > .blk { grid-template-columns: minmax(0, var(--main)) minmax(0, var(--note)); column-gap: var(--gap); }
}
.blk > * { grid-column: 1; min-width: 0; }
.blk > .note { grid-column: 2; grid-row: 1; align-self: start; }

.note {
  margin: .3rem 0 1rem; padding-left: 1rem; border-left: 1px solid var(--rule-strong);
  font-size: .875rem; line-height: 1.5; color: var(--ink-2);
}
.note strong { color: var(--ink); }

/* ---------- Type ---------- */
h1, h2, h3 { font-weight: 650; text-wrap: balance; }
h1 { font-size: clamp(2.3rem, 5.2vw, 3.7rem); line-height: 1.07; letter-spacing: -0.02em; margin: 0 0 1.1rem; max-width: 21ch; font-weight: 700; }
h2 { font-size: 1.7rem; line-height: 1.2; letter-spacing: -0.01em; margin: 2.6rem 0 .9rem; scroll-margin-top: 1.5rem; }
h3 { font-size: 1.15rem; line-height: 1.3; margin: 1.8rem 0 .4rem; }
p { margin: 0 0 1rem; }
.lede { font-size: 1.25rem; line-height: 1.55; color: var(--ink-2); max-width: 40rem; margin-bottom: 1.6rem; }
.small { font-size: .875rem; line-height: 1.5; color: var(--ink-3); }
em { font-style: italic; }
ul { padding-left: 1.2rem; margin: 0 0 1rem; }
li { margin-bottom: .4rem; }
li::marker { color: var(--ink-3); }

/* ---------- Hero ---------- */
.hero { padding-top: .25rem; }
.crumbs ol { display: flex; flex-wrap: wrap; gap: .1rem .6rem; list-style: none; margin: 0 0 1.4rem; padding: 0; font-size: .9rem; color: var(--ink-3); }
.crumbs li { margin: 0; }
.crumbs li + li::before { content: "/"; margin-right: .6rem; color: var(--rule-strong); }
.crumbs a { color: var(--ink-3); }
.facts { display: grid; grid-template-columns: repeat(3, auto); justify-content: start; gap: .25rem 3rem; margin: 0 0 1.4rem; padding-block: .9rem; border-block: 1px solid var(--rule-strong); max-width: 40rem; }
.facts div { min-width: 0; }
.facts dt { font-size: .85rem; color: var(--ink-3); }
.facts dd { margin: 0; font-weight: 500; }
.outcomes { max-width: 40rem; }
.outcomes p { margin-bottom: .4rem; font-weight: 600; }

/* ---------- The ledger (the one loud thing) ---------- */
.controls { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem 2.5rem; margin: 0 0 1.4rem; }
.ctl label { display: flex; justify-content: space-between; gap: 1rem; font-weight: 600; margin-bottom: .2rem; }
.ctl output { font-weight: 700; font-variant-numeric: tabular-nums; white-space: nowrap; }
.ctl input[type="range"] { width: 100%; margin: 0; height: 1.75rem; accent-color: var(--ink); cursor: pointer; }
.ctl .ends { display: flex; justify-content: space-between; font-size: .8rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }

.ledger {
  background: var(--sheet); border: 1px solid var(--rule-strong); border-radius: 2px;
  box-shadow: 0 1px 0 var(--rule), 0 22px 28px -24px var(--shadow);
}
.ledger-pages { display: grid; grid-template-columns: 1fr 1fr; }
.side, .bridge {
  position: relative;
  padding: 0 1.25rem 0 3.1rem;
  background-image: repeating-linear-gradient(to bottom, transparent 0, transparent calc(var(--row) - 1px), var(--rule) calc(var(--row) - 1px), var(--rule) var(--row));
}
.side::before, .bridge::before {
  content: ""; position: absolute; left: 2.15rem; top: 0; bottom: 0; width: 0; border-left: 3px double var(--margin-line);
}
.side + .side { border-left: 1px solid var(--rule-strong); box-shadow: inset 14px 0 14px -14px var(--shadow); }
.bridge { border-top: 1px solid var(--rule-strong); }

.line { display: flex; justify-content: space-between; align-items: center; gap: 1rem; height: var(--row); line-height: var(--row); }
.line > span:first-child { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.side-title { font-weight: 700; font-size: 1.08rem; }
.side-sub { font-style: italic; color: var(--ink-3); font-size: .9rem; }
.unit { justify-content: flex-end; color: var(--ink-3); font-size: .85rem; }
.fig { position: relative; min-width: 6.4rem; text-align: right; font-variant-numeric: tabular-nums; padding-right: .15rem; }
.neg { color: var(--red); }
.total { font-weight: 700; }
.total .fig::before, .total .fig::after { content: ""; position: absolute; left: 0; right: 0; }
.total .fig::before { top: 3px; border-top: 1px solid var(--ink); }
.total .fig::after { bottom: 3px; border-bottom: 3px double var(--ink); }
.fig.flash { animation: flash .9s ease-out; }
@keyframes flash { from { background: var(--flash); } to { background: transparent; } }

.verdict { margin: 1.1rem 0 0; font-size: 1.1rem; line-height: 1.55; font-weight: 500; max-width: 46rem; }

/* ---------- Plain tables ---------- */
.tablewrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-variant-numeric: tabular-nums; }
caption { text-align: left; font-weight: 700; padding-bottom: .6rem; }
th, td { text-align: left; vertical-align: top; padding: .65rem 1rem .65rem 0; border-bottom: 1px solid var(--rule); }
thead th { border-bottom: 2px solid var(--ink); font-weight: 700; font-size: .95rem; }
th[scope="row"] { font-weight: 500; }
.drift td:first-child { padding-right: 1.4rem; }

/* ---------- Formula ---------- */
.formula { max-width: 36rem; margin: 1.2rem 0 1.4rem; background: var(--sheet); border: 1px solid var(--rule-strong); padding: 0 1.25rem; }
.formula .line { justify-content: flex-start; align-items: flex-start; gap: .9rem; height: auto; min-height: var(--row); line-height: 1.45; padding: .3rem 0; border-bottom: 1px solid var(--rule); }
.formula .line:last-child { border-bottom: 0; }
.formula .line > span:first-child { overflow: visible; white-space: normal; flex: none; }
.formula .line > span:last-child { min-width: 0; overflow-wrap: anywhere; }
.formula .op { width: 1rem; text-align: center; color: var(--ink-3); font-weight: 700; }
.formula .result { position: relative; font-weight: 700; }
.formula .result::before, .formula .result::after { content: ""; position: absolute; left: 0; right: 0; }
.formula .result::before { top: 3px; border-top: 1px solid var(--ink); }
.formula .result::after { bottom: 3px; border-bottom: 3px double var(--ink); }

/* ---------- Titan: chart and statement ---------- */
.figure-title { font-weight: 700; margin: 0 0 .15rem; }
.figure-sub { margin: 0 0 1rem; color: var(--ink-3); font-size: .9rem; }
.wf { --lab: 15.5rem; --val: 4.6rem; margin: 1.6rem 0 0; }
.wf-rows { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: var(--lab) minmax(0, 1fr) var(--val); align-items: center; position: relative; }
.wf-rows > .wf-row { display: contents; }
.wf-rows > .wf-row > * { padding-block: .22rem; }
.wf-label { grid-column: 1; padding-right: 1rem; line-height: 1.3; font-size: .975rem; }
.wf-track { grid-column: 2; position: relative; height: 1.7rem; }
.wf-bar { position: absolute; top: .3rem; height: 1.1rem; min-width: 3px; border-radius: 4px; }
.wf-row-total .wf-bar { border-radius: 0 4px 4px 0; }
.wf-up .wf-bar { background: var(--green); }
.wf-down .wf-bar { background: var(--red); }
.wf-row-total .wf-bar { background: var(--ink); }
.wf-val { grid-column: 3; text-align: right; font-variant-numeric: tabular-nums; padding-left: .5rem; }
.wf-row-total .wf-label, .wf-row-total .wf-val { font-weight: 700; }
.wf-grid { position: absolute; left: var(--lab); right: var(--val); top: 0; bottom: 1.4rem; pointer-events: none; z-index: 0; background-image: linear-gradient(to right, var(--rule) 1px, transparent 1px); background-size: calc(100% / 5.5 * 1) 100%; background-repeat: repeat-x; }
.wf-rows > .wf-row > .wf-track { z-index: 1; }
.wf-axis { grid-column: 2; position: relative; height: 1.4rem; font-size: .8rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.wf-axis span { position: absolute; top: .2rem; transform: translateX(-50%); }
.wf-axis span:first-child { transform: none; }
.wf-key { margin: .9rem 0 0; display: flex; flex-wrap: wrap; gap: .25rem 1.4rem; font-size: .875rem; color: var(--ink-2); }
.wf-key span::before { content: ""; display: inline-block; width: .9rem; height: .6rem; border-radius: 2px; margin-right: .45rem; vertical-align: baseline; }
.wf-key .k-total::before { background: var(--ink); }
.wf-key .k-up::before { background: var(--green); }
.wf-key .k-down::before { background: var(--red); }

.stmt-wrap { background: var(--sheet); border: 1px solid var(--rule-strong); border-radius: 2px; padding: 1rem 1.25rem .6rem; box-shadow: 0 1px 0 var(--rule), 0 22px 28px -24px var(--shadow); }
.stmt th, .stmt td { padding-block: .5rem; }
.stmt td, .stmt thead th:not(:first-child) { text-align: right; white-space: nowrap; padding-right: 0; padding-left: 1.2rem; }
.stmt tr.sub th, .stmt tr.sub td { font-weight: 700; border-top: 1px solid var(--ink); }
.stmt tr.grand th, .stmt tr.grand td { font-weight: 700; border-top: 1px solid var(--ink); border-bottom: 3px double var(--ink); }
.stmt tr.pre th, .stmt tr.pre td { border-bottom-color: var(--ink); }
.stmt tr.ref th, .stmt tr.ref td { color: var(--ink-2); }
.stmt tr.gapbefore th, .stmt tr.gapbefore td { padding-top: 1.1rem; }
.stmt .indent { padding-left: 1.1rem; }

/* ---------- Single-slider controls, key terms ---------- */
.controls.one { grid-template-columns: minmax(0, 28rem); }
.terms { margin: 0 0 1rem; border-top: 2px solid var(--ink); }
.terms div { display: grid; grid-template-columns: 11rem minmax(0, 1fr); gap: .2rem 1.4rem; padding: .7rem 0; border-bottom: 1px solid var(--rule); }
.terms dt { font-weight: 650; }
.terms dd { margin: 0; color: var(--ink-2); }
.cols-2 th:first-child, .cols-2 td:first-child { width: 42%; }

/* ---------- Practice, sources, pager, footer ---------- */
.q { margin: 0 0 1.6rem; }
.q > p { margin-bottom: .5rem; }
details.answer summary { cursor: pointer; font-weight: 600; width: fit-content; }
details.answer summary::marker { color: var(--ink-3); }
details.answer[open] summary { margin-bottom: .4rem; }
details.answer p { margin: 0; padding-left: 1rem; border-left: 2px solid var(--rule-strong); color: var(--ink-2); }

.sources { padding-left: 1.3rem; }
.review { margin-top: 1.6rem; padding-top: 1rem; border-top: 1px solid var(--rule-strong); display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .5rem 1.5rem; }
.review dt { font-size: .85rem; color: var(--ink-3); }
.review dd { margin: 0; }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin-top: 4rem; }
.pager a { display: block; padding-top: .7rem; border-top: 2px solid var(--ink); text-decoration: none; }
.pager a:hover .pg-title { text-decoration: underline; text-decoration-thickness: 2px; }
.pager small { display: block; color: var(--ink-3); font-size: .85rem; }
.pager .pg-title { font-weight: 650; font-size: 1.1rem; }
.pager .next { text-align: right; }

.site-footer { border-top: 3px double var(--ink); padding-block: 1.6rem 2.6rem; font-size: .9rem; color: var(--ink-2); }
.site-footer .wrap { display: grid; gap: .8rem; }
.site-footer ul { display: flex; flex-wrap: wrap; gap: .3rem 1.4rem; list-style: none; margin: 0; padding: 0; }
.site-footer li { margin: 0; }
.site-footer a { color: var(--ink-2); }

/* ---------- Responsive ---------- */
@media (max-width: 1180px) {
  .shell { grid-template-columns: minmax(0, 1fr); }
  .rail { position: static; margin-bottom: 1.6rem; max-width: 40rem; border-block: 1px solid var(--rule-strong); padding-block: .8rem; }
  .rail summary { cursor: pointer; margin: 0; }
  .rail[open] summary { margin-bottom: .6rem; }
  .rail summary::after { content: "Show"; float: right; font-weight: 400; color: var(--ink-3); font-size: .875rem; }
  .rail[open] summary::after { content: "Hide"; }
}
@media (max-width: 900px) {
  :root { --gap: 0rem; }
  .article, .article > .blk { grid-template-columns: minmax(0, 1fr); }
  .blk > .note { grid-column: 1; grid-row: auto; margin: 0 0 1.2rem; border-left-width: 2px; }
  .facts { grid-template-columns: 1fr; }
  .review { grid-template-columns: 1fr; }
  .controls { grid-template-columns: 1fr; }
  h2 { margin-top: 2.4rem; font-size: 1.5rem; }
}
@media (max-width: 720px) {
  .ledger-pages { grid-template-columns: 1fr; }
  .side + .side { border-left: 0; border-top: 1px solid var(--rule-strong); box-shadow: none; }
  .side, .bridge { padding-left: 2.8rem; padding-right: .9rem; }
  .side::before, .bridge::before { left: 1.9rem; }
  .ledger { font-size: .9375rem; }
  .fig { min-width: 5.2rem; }
  .site-nav ul { gap: .25rem 1.1rem; }
  .site-nav a { font-size: .9rem; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { text-align: left; }
  .site-header .wrap { flex-direction: column; align-items: flex-start; }

  .terms div { grid-template-columns: 1fr; }
  .drift thead { position: absolute; left: -9999px; }
  .drift, .drift tbody, .drift tr, .drift td { display: block; }
  .drift tr { padding-block: .8rem; border-bottom: 1px solid var(--rule); }
  .drift td { border: 0; padding: .15rem 0; }
  .drift td:first-child { font-weight: 650; padding-bottom: .3rem; }
  .drift td:empty { display: none; }
  .drift td[data-label]::before { content: attr(data-label) ": "; color: var(--ink-3); font-size: .875rem; }

  .wf-rows { grid-template-columns: minmax(0, 1fr) auto; }
  .wf-label { grid-column: 1 / -1; padding-bottom: 0; }
  .wf-grid, .wf-axis { display: none; }
  .wf-track { grid-column: 1; }
  .wf-val { grid-column: 2; }
  .stmt-wrap { padding-inline: .8rem; }
  .stmt td, .stmt thead th:not(:first-child) { padding-left: .7rem; }
}

@media (max-width: 420px) {
  .side, .bridge { padding-left: 2.4rem; padding-right: .7rem; }
  .side::before, .bridge::before { left: 1.6rem; }
  .fig { min-width: 4.7rem; }
}

@media (prefers-reduced-motion: reduce) {
  .fig.flash { animation: none; }
}

/* ---------- Added for lessons 1 to 4: subtotal rule, sorter ---------- */
.sub { font-weight: 700; }
.sub .fig::before { content: ""; position: absolute; left: 0; right: 0; top: 3px; border-top: 1px solid var(--ink); }
.sorter { border-top: 2px solid var(--ink); margin: 0 0 1rem; padding: 0; list-style: none; counter-reset: s; }
.sorter li { counter-increment: s; display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: .35rem 1.2rem; align-items: center; padding: .65rem 0; border-bottom: 1px solid var(--rule); }
.sorter .item::before { content: counter(s) ". "; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.sorter .opts { display: flex; gap: .35rem; flex-wrap: wrap; }
.sorter button { font: inherit; font-size: .9rem; padding: .2rem .7rem; border: 1px solid var(--rule-strong); background: var(--sheet); color: var(--ink); border-radius: 2px; cursor: pointer; }
.sorter button:hover { border-color: var(--ink); }
.sorter button:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
.sorter li.done button { cursor: default; opacity: .55; }
.sorter li.done button.picked { opacity: 1; font-weight: 700; }
.sorter li.right button.picked { border-color: var(--green); color: var(--green); }
.sorter li.wrong button.picked { border-color: var(--red); color: var(--red); }
.sorter li.done button.answer { opacity: 1; border-color: var(--green); color: var(--green); font-weight: 700; }
.sorter .why { grid-column: 1 / -1; margin: 0; font-size: .95rem; color: var(--ink-2); }
.score { font-weight: 600; margin: 0 0 1.4rem; }
@media (max-width: 640px) { .sorter li { grid-template-columns: 1fr; } }
.stmt tr.head th { font-weight: 700; padding-top: 1.1rem; border-bottom-color: var(--rule); }
.stmt.words td:last-child, .stmt.words thead th:last-child { text-align: left; padding-left: 1.4rem; }
.stmt.words td:last-child { font-weight: 400; color: var(--ink-2); }
.stmt.words td:nth-child(2), .stmt.words thead th:nth-child(2) { white-space: nowrap; }
.eq-line { display: flex; flex-wrap: wrap; align-items: baseline; gap: .3rem 1.1rem; max-width: 29rem; margin: 1.2rem 0 1.4rem; padding: .7rem 1.25rem; font-size: 1.5rem; font-weight: 700; background: var(--sheet); border: 1px solid var(--rule-strong); border-bottom: 3px double var(--ink); }
.eq-line .op { color: var(--ink-3); }

/* ---------- Layout on wide and middle-sized screens; ad slots ---------- */
@media (min-width: 1181px) { :root { --main: 38rem; } }
@media (max-width: 1180px) {
  .article, .article > .blk { grid-template-columns: minmax(0, 1fr); }
  .blk > .note { grid-column: 1; grid-row: auto; margin: 0 0 1.2rem; border-left-width: 2px; }
}
@media (max-width: 1180px) and (min-width: 901px) {
  /* one centred reading column; ledgers and tables break out symmetrically */
  .article { max-width: var(--main); margin-inline: auto; }
  .rail { max-width: var(--main); margin-inline: auto; }
  .article > .wide { width: min(53.5rem, calc(100vw - 2rem)); margin-left: 50%; transform: translateX(-50%); }
  .wide > .verdict { max-width: var(--main); margin-inline: auto; }
}
.ad { margin: 2.4rem 0; padding: .5rem 0 .6rem; border-block: 1px solid var(--rule); min-height: 18rem; }
.ad-label { display: block; font-size: .75rem; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-3); margin-bottom: .4rem; }

/* ---------- Lesson 9: balance sheet builder ---------- */
.builder { border-top: 2px solid var(--ink); margin: 0 0 1.4rem; padding: 0; list-style: none; counter-reset: b; }
.builder li { counter-increment: b; display: grid; grid-template-columns: minmax(0, 1fr) auto auto; gap: .3rem 1.2rem; align-items: center; padding: .6rem 0; border-bottom: 1px solid var(--rule); }
.builder .item::before { content: counter(b) ". "; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.builder .amt { font-variant-numeric: tabular-nums; text-align: right; min-width: 6rem; }
.builder select { font: inherit; font-size: .9rem; padding: .25rem .4rem; border: 1px solid var(--rule-strong); background: var(--sheet); color: var(--ink); border-radius: 2px; max-width: 13rem; }
.builder li.right select { border-color: var(--green); color: var(--green); }
.builder li.wrong select { border-color: var(--red); color: var(--red); }
.builder .why { grid-column: 1 / -1; margin: 0; font-size: .95rem; color: var(--ink-2); }
.btnrow { display: flex; flex-wrap: wrap; gap: .6rem; margin: 0 0 1.2rem; }
.btn { font: inherit; font-size: .95rem; padding: .35rem .9rem; border: 1px solid var(--ink); background: var(--sheet); color: var(--ink); border-radius: 2px; cursor: pointer; }
.btn:hover { background: var(--ink); color: var(--paper); }
.btn:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
.btn.quiet { border-color: var(--rule-strong); }
@media (max-width: 640px) { .builder li { grid-template-columns: minmax(0, 1fr) auto; } .builder select { grid-column: 1 / -1; max-width: none; } }

/* stacked three-statement ledgers (lessons 7 and 11) */
.ledger-pages.stack { grid-template-columns: 1fr; }
.ledger-pages.stack .side + .side { border-left: 0; border-top: 1px solid var(--rule-strong); box-shadow: none; }
@media (min-width: 721px) { .ledger-pages.stack .side { padding-right: 2rem; } }

/* ---------- Site pages: home, hubs, policies ---------- */
.page { max-width: 46rem; margin: 0 auto; padding-block: 2.2rem 4.5rem; }
.page h1 { max-width: 24ch; font-size: clamp(2rem, 4.6vw, 3.1rem); }
.page h2 { margin-top: 2.6rem; }
.page .updated { color: var(--ink-3); font-size: .9rem; margin: -.4rem 0 2rem; }
.kicker { font-size: .85rem; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); margin: 0 0 .8rem; }
a.btn { text-decoration: none; display: inline-block; }
.btn.primary { background: var(--ink); color: var(--paper); }
.btn.primary:hover { opacity: .88; }
.cta { display: flex; flex-wrap: wrap; gap: .8rem; margin: 1.6rem 0 0; }
.home { padding-block: 2.6rem 4.5rem; }
.home-hero { max-width: 48rem; padding-bottom: 1rem; }
.home-hero h1 { max-width: 20ch; }
.steps3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.2rem 2.2rem; margin: 1rem 0 0; padding: 1rem 0 0; list-style: none; border-top: 2px solid var(--ink); }
.steps3 li { margin: 0; }
.steps3 strong { display: block; font-size: 1.1rem; margin-bottom: .2rem; }
.steps3 span { color: var(--ink-2); }
.lessons { list-style: none; margin: 0 0 1rem; padding: 0; border-top: 2px solid var(--ink); }
.lessons li { margin: 0; border-bottom: 1px solid var(--rule); }
.lessons a { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: .1rem 1rem; padding: .85rem 0; text-decoration: none; }
.lessons a:hover .ttl { text-decoration: underline; text-decoration-thickness: 2px; }
.lessons .ttl { font-weight: 650; font-size: 1.1rem; grid-row: 1; grid-column: 1; }
.lessons .dsc { grid-column: 1; color: var(--ink-2); }
.lessons .meta { color: var(--ink-3); font-size: .9rem; white-space: nowrap; grid-row: 1; grid-column: 2; }
.mod-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: .3rem 1.5rem; margin-top: 3rem; }
.mod-head h2 { margin: 0; }
.mod-head .count { color: var(--ink-3); }
.trust { background: var(--sheet); border: 1px solid var(--rule-strong); padding: 1.3rem 1.6rem 1.1rem; margin-top: 3.2rem; box-shadow: 0 1px 0 var(--rule); }
.trust h2 { margin-top: 0; font-size: 1.3rem; }
.sheet-eq { margin: 2rem 0 0; }
@media (max-width: 720px) {
  .steps3 { grid-template-columns: 1fr; }
  .lessons a { grid-template-columns: minmax(0, 1fr); }
  .lessons .meta { grid-column: 1; grid-row: auto; }
}
.wide > .verdict { margin-bottom: 1.6rem; }
.walk { list-style: none; margin: 0 0 1.4rem; padding: 0; border-top: 2px solid var(--ink); max-width: 38rem; }
.walk li { display: grid; grid-template-columns: 2.2rem minmax(0, 1fr); padding: .5rem 0; border-bottom: 1px solid var(--rule); margin: 0; }
.walk .sign { color: var(--ink-3); text-align: center; font-variant-numeric: tabular-nums; }
.walk .result { font-weight: 700; border-top: 1px solid var(--ink); border-bottom: 3px double var(--ink); }
.walk .result .sign { color: var(--ink); }