/* ISO Me — "standards document / technical specification" design.
   Navy #0E2A47 + signal amber #F2A007 (complementary), white, grid lines #E3E8EF.
   IBM Plex Sans (body) + IBM Plex Serif (headings), self-hosted (SIL OFL, see /assets/fonts/OFL.txt). */

@font-face { font-family: "IBM Plex Sans"; src: url("../fonts/ibm-plex-sans-var.woff2") format("woff2"); font-weight: 400 700; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("../fonts/ibm-plex-sans-italic-var.woff2") format("woff2"); font-weight: 400 600; font-style: italic; font-display: swap; }
@font-face { font-family: "IBM Plex Serif"; src: url("../fonts/ibm-plex-serif-400.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Serif"; src: url("../fonts/ibm-plex-serif-400i.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "IBM Plex Serif"; src: url("../fonts/ibm-plex-serif-600.woff2") format("woff2"); font-weight: 600; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Serif"; src: url("../fonts/ibm-plex-serif-700.woff2") format("woff2"); font-weight: 700; font-style: normal; font-display: swap; }

:root {
  --navy: #0E2A47;
  --navy-2: #1B3F66;
  --navy-3: #2E5A88;
  --amber: #F2A007;
  --amber-soft: #FDF1D6;
  --amber-ink: #8A5800;      /* amber family for text on white: 6.0:1 */
  --ink: #14202E;
  --muted: #4A5A6E;          /* 7.0:1 on white */
  --grid: #E3E8EF;
  --grid-2: #CBD4E0;
  --wash: #F5F7FA;
  --paper: #FFFFFF;
  --ok: #1D6B45;
  --ok-soft: #E4F3EA;
  --bad: #A3271F;
  --bad-soft: #FBE9E7;
  --link: #0F4C86;
  --focus: #F2A007;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --serif: "IBM Plex Serif", Georgia, "Times New Roman", serif;
  --gutter: 16px;
  --side: 248px;
  --toc: 220px;
  --measure: 46rem;
  --radius: 2px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-padding-top: 16px; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 1.0625rem/1.65 var(--sans); font-feature-settings: "kern", "liga"; overflow-x: hidden; }
img { max-width: 100%; height: auto; }
a { color: var(--link); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--navy); text-decoration-color: var(--amber); text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; box-shadow: 0 0 0 5px var(--navy); }
h1, h2, h3, h4 { font-family: var(--serif); font-weight: 600; color: var(--navy); line-height: 1.22; margin: 1.8em 0 .55em; letter-spacing: -.005em; }
h1 { font-size: clamp(1.85rem, 1.3rem + 2.2vw, 2.7rem); margin-top: .2em; }
h2 { font-size: clamp(1.35rem, 1.15rem + .8vw, 1.7rem); }
h3 { font-size: 1.2rem; }
h4 { font-size: 1.05rem; }
p, ul, ol, dl { margin: 0 0 1em; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .88em; background: var(--wash); border: 1px solid var(--grid); padding: 0 .3em; }
hr { border: 0; border-top: 1px solid var(--grid-2); margin: 2em 0; }
.vh { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--muted); }
.sub { display: block; font-size: .82rem; color: var(--muted); font-weight: 400; font-family: var(--sans); }
.nowrap { white-space: nowrap; }
.num { font-variant-numeric: tabular-nums; text-align: right; }

/* clause numbers — the site's signature motif */
.cl { display: inline-block; min-width: 2.4em; font-family: var(--sans); font-weight: 600; font-variant-numeric: tabular-nums lining-nums; color: var(--amber-ink); letter-spacing: .01em; }
h2 > .cl, h3 > .cl { position: relative; padding-right: .35em; }
h2 > .cl::after { content: ""; position: absolute; left: 0; bottom: -.25em; width: 1.4em; height: 3px; background: var(--amber); }

.skip { position: absolute; left: 8px; top: -60px; z-index: 50; background: var(--amber); color: var(--navy); font-weight: 700; padding: 10px 14px; text-decoration: none; }
.skip:focus { top: 8px; }

/* ---------------------------------------------------------------- header */
.site-head { background: var(--navy); color: #fff; border-bottom: 4px solid var(--amber); }
.head-in { max-width: 1440px; margin: 0 auto; padding: 10px var(--gutter); display: flex; align-items: center; gap: 12px 28px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 12px; color: #fff; text-decoration: none; margin-right: auto; }
.brand:hover { color: #fff; }
.brand-mark { width: 44px; height: 44px; border: 2px solid #fff; display: grid; place-items: end start; padding: 0 0 3px 5px; position: relative; flex: none; }
.brand-mark::before { content: ""; position: absolute; right: -2px; top: -2px; width: 14px; height: 14px; background: var(--amber); }
.brand-mark span { font: 700 .82rem/1 var(--sans); letter-spacing: .06em; }
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-name { font: 600 1.45rem/1.1 var(--serif); }
.brand-sub { font-size: .74rem; letter-spacing: .08em; text-transform: uppercase; color: #C9D6E6; margin-top: 3px; }
.top-nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 2px; }
.top-nav a { display: block; color: #fff; text-decoration: none; padding: 10px 11px; font-size: .95rem; font-weight: 500; border-bottom: 3px solid transparent; }
.top-nav a:hover { border-bottom-color: #C9D6E6; color: #fff; }
.top-nav a[aria-current] { border-bottom-color: var(--amber); }
.menu { display: none; position: relative; }
.menu summary { list-style: none; cursor: pointer; color: #fff; font-weight: 600; padding: 9px 12px; border: 1px solid #5C7899; display: flex; align-items: center; gap: 10px; min-height: 44px; }
.menu summary::-webkit-details-marker { display: none; }
.menu-bars { width: 18px; height: 12px; border-top: 2px solid #fff; border-bottom: 2px solid #fff; position: relative; }
.menu-bars::after { content: ""; position: absolute; left: 0; right: 0; top: 3px; border-top: 2px solid #fff; }
.menu[open] summary { background: var(--navy-2); }
.menu nav { position: absolute; right: 0; top: calc(100% + 6px); background: var(--paper); border: 1px solid var(--grid-2); border-top: 4px solid var(--amber); min-width: 240px; z-index: 30; box-shadow: 0 10px 30px rgba(14, 42, 71, .18); }
.menu ul { list-style: none; margin: 0; padding: 6px 0; }
.menu a { display: block; padding: 11px 16px; color: var(--navy); text-decoration: none; font-weight: 500; }
.menu a:hover, .menu a[aria-current] { background: var(--wash); box-shadow: inset 3px 0 0 var(--amber); }

/* ----------------------------------------------------------------- shell */
.shell { max-width: 1440px; margin: 0 auto; display: grid; grid-template-columns: var(--side) minmax(0, 1fr); grid-template-areas: "side main"; }
.shell.has-toc { grid-template-columns: var(--side) minmax(0, 1fr) var(--toc); grid-template-areas: "side main toc"; }
.shell.no-side { grid-template-columns: minmax(0, 1fr); grid-template-areas: "main"; max-width: none; }
.shell.no-side > main { padding: 0; }
.shell > main { grid-area: main; padding: 26px clamp(16px, 3vw, 48px) 64px; min-width: 0; outline: none; }
.shell:not(.no-side):not(.is-wide) > main > * { max-width: 62rem; }
.prose > :not(.table-wrap), .shell:not(.no-side) > main > p, .shell:not(.no-side) > main > section > p, .doc-head .lead, .doc-meta, .index-list, .checklist-wrap, .note, .quiz, .faq, .gloss, .guide-list, .levels { max-width: var(--measure); }
.side { grid-area: side; border-right: 1px solid var(--grid); padding: 22px 18px 40px var(--gutter); background: linear-gradient(var(--wash), var(--wash)) no-repeat; font-size: .92rem; }
.side-h { font: 600 .78rem/1 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--muted); margin: 0 0 14px; }
.side-sec { margin-bottom: 18px; }
.side-t { font-weight: 600; color: var(--navy); margin: 0 0 4px; }
.side-t .cl { min-width: 1.6em; }
.side ul { list-style: none; margin: 0; padding: 0 0 0 1.6em; border-left: 1px solid var(--grid-2); margin-left: .35em; }
.side li a { display: block; padding: 4px 8px; color: var(--ink); text-decoration: none; line-height: 1.35; margin-left: -1px; border-left: 3px solid transparent; }
.side li a:hover { color: var(--navy); border-left-color: var(--grid-2); background: var(--paper); }
.side li a[aria-current] { border-left-color: var(--amber); background: var(--paper); font-weight: 600; color: var(--navy); }
.toc { grid-area: toc; padding: 30px var(--gutter) 30px 8px; font-size: .88rem; }
.toc > * { position: relative; }
.toc-h { font: 600 .75rem/1 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--muted); margin: 0 0 10px; }
.toc ol { list-style: none; margin: 0; padding: 0; border-left: 2px solid var(--grid); position: sticky; top: 16px; }
.toc li a { display: block; padding: 4px 0 4px 12px; color: var(--muted); text-decoration: none; line-height: 1.35; margin-left: -2px; border-left: 2px solid transparent; }
.toc li.lv3 a { padding-left: 24px; font-size: .84rem; }
.toc li a:hover { color: var(--navy); border-left-color: var(--amber); }

/* ------------------------------------------------------------ doc header */
.crumbs ol { list-style: none; padding: 0; margin: 0 0 14px; display: flex; flex-wrap: wrap; gap: 4px 0; font-size: .86rem; color: var(--muted); }
.crumbs li + li::before { content: "/"; margin: 0 8px; color: var(--grid-2); }
.crumbs a { color: var(--muted); }
.doc-head { border-bottom: 1px solid var(--grid-2); padding-bottom: 18px; margin-bottom: 28px; }
.kicker { font: 600 .8rem/1.3 var(--sans); letter-spacing: .1em; text-transform: uppercase; color: var(--amber-ink); margin: 0 0 6px; }
.lead { font-size: 1.15rem; color: #2B3A4C; max-width: 44rem; }
.doc-meta { display: grid; grid-template-columns: 1fr; margin: 18px 0 0; border: 1px solid var(--grid-2); background: var(--paper); font-size: .93rem; }
.doc-meta > div { display: grid; grid-template-columns: minmax(8.5rem, 28%) 1fr; border-top: 1px solid var(--grid); }
.doc-meta > div:first-child { border-top: 0; }
.doc-meta dt { background: var(--wash); padding: 8px 12px; font-weight: 600; color: var(--navy); border-right: 1px solid var(--grid); }
.doc-meta dd { margin: 0; padding: 8px 12px; }

/* --------------------------------------------------------------- prose */
.prose { margin-bottom: 1.5em; }
.prose h2:first-child, section > h2:first-child { margin-top: .6em; }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li { margin-bottom: .35em; }
.prose li::marker { color: var(--amber-ink); }
.prose h3 .cl, .prose h4 .cl { min-width: 2.8em; }
.note { border-left: 4px solid var(--amber); background: var(--amber-soft); padding: 12px 16px; margin: 1.2em 0; font-size: .97rem; }
.empty { background: var(--wash); border: 1px dashed var(--grid-2); padding: 14px 16px; color: var(--muted); }
.figure { margin: 0 0 24px; max-width: var(--measure); }
.figure img { display: block; width: 100%; aspect-ratio: 16 / 8; object-fit: cover; border: 1px solid var(--grid); }
.figure figcaption { font-size: .8rem; color: var(--muted); margin-top: 6px; }
.figure figcaption a { color: var(--muted); }

/* --------------------------------------------------------------- tables */
.table-wrap { overflow-x: auto; margin: 0 0 1.4em; border: 1px solid var(--grid-2); background: var(--paper); }
.table-wrap:focus-visible { outline-offset: 0; }
table { width: 100%; border-collapse: collapse; font-size: .95rem; }
th, td { text-align: left; vertical-align: top; padding: 9px 12px; border-bottom: 1px solid var(--grid); }
thead th { background: var(--wash); color: var(--navy); font: 600 .8rem/1.3 var(--sans); letter-spacing: .05em; text-transform: uppercase; border-bottom: 2px solid var(--navy); }
tbody th { font-weight: 600; color: var(--navy); }
tbody th a { color: var(--navy); }
tbody tr:last-child > * { border-bottom: 0; }
tbody tr:hover > * { background: #FAFBFD; }
td + td, th + td, th + th { border-left: 1px solid var(--grid); }
.data.courses tbody th { font-weight: 500; min-width: 15rem; }
.go-link { font-weight: 600; }
.go-link::after { content: " ↗"; font-size: .85em; }

/* matrix */
.matrix-wrap { border-color: var(--navy); }
table.matrix { min-width: 760px; }
.matrix thead th { text-align: center; vertical-align: bottom; padding: 10px 6px; font-size: .74rem; white-space: normal; line-height: 1.2; }
.matrix thead th a { color: var(--navy); text-decoration: none; display: block; }
.matrix thead th a:hover { text-decoration: underline; }
.matrix thead th.corner { text-align: left; padding-left: 12px; }
.matrix tbody th { position: sticky; left: 0; background: var(--paper); z-index: 1; min-width: 12rem; border-right: 2px solid var(--navy); padding: 7px 12px; }
.matrix tbody th a { text-decoration: none; display: block; }
.matrix .code { display: block; font-weight: 600; font-variant-numeric: tabular-nums; }
.matrix .topic { display: block; font-size: .78rem; color: var(--muted); font-weight: 400; }
.matrix td { text-align: center; vertical-align: middle; padding: 0; height: 52px; background-image: linear-gradient(var(--grid), var(--grid)); background-size: 1px 100%; background-repeat: no-repeat; background-position: 50% 0; background-blend-mode: normal; }
.matrix td { background: none; }
.matrix td.on a { display: flex; align-items: center; justify-content: center; gap: 6px; height: 100%; min-height: 52px; text-decoration: none; color: var(--navy); font-weight: 600; font-variant-numeric: tabular-nums; }
.matrix td.on a:hover, .matrix td.on a:focus-visible { background: var(--amber-soft); }
.matrix td.on > .dot + .n { font-weight: 600; color: var(--navy); }
.matrix td.on:not(:has(a)) { color: var(--navy); }
.dot { display: inline-block; width: 11px; height: 11px; background: var(--amber); border: 2px solid var(--navy); flex: none; }
.matrix .none { color: var(--grid-2); font-weight: 600; }
.matrix-key { font-size: .85rem; color: var(--muted); display: flex; gap: 8px; align-items: baseline; flex-wrap: wrap; }
.matrix-key .dot { transform: translateY(1px); }
.provgrid td.on { color: var(--navy); }
.provgrid td.on .n { margin-left: 6px; font-weight: 600; }

/* flags */
.flag { display: inline-block; font: 600 .72rem/1.2 var(--sans); letter-spacing: .06em; text-transform: uppercase; padding: 3px 7px; border: 1px solid currentColor; margin-right: 4px; vertical-align: 1px; white-space: nowrap; }
.flag-new { color: var(--ok); background: var(--ok-soft); }
.flag-revising { color: var(--amber-ink); background: var(--amber-soft); }
.flag-stable { color: var(--navy-3); background: var(--wash); }

/* lists */
.index-list { list-style: none; padding: 0; margin: 0 0 1.2em; border-top: 1px solid var(--grid); }
.index-list li { padding: 10px 0 10px 1.6em; border-bottom: 1px solid var(--grid); position: relative; }
.index-list li::before { content: ""; position: absolute; left: 2px; top: 1.05em; width: 9px; height: 9px; border: 2px solid var(--navy); background: var(--paper); }
.index-list li a { font-weight: 600; }
.index-list.cols { columns: 2 18rem; column-gap: 32px; border-top: 0; }
.index-list.cols li { break-inside: avoid; }
.text-link { font-weight: 600; }
.see-also { font-size: .95rem; }

/* level / scheme list (home, schemes) */
.levels { list-style: none; padding: 0; margin: 0 0 1.5em; border-top: 2px solid var(--navy); }
.levels li a { display: grid; grid-template-columns: 3.2em minmax(10rem, 15rem) 1fr; gap: 4px 16px; padding: 14px 4px; border-bottom: 1px solid var(--grid); text-decoration: none; color: var(--ink); align-items: baseline; }
.levels li a:hover { background: var(--wash); }
.levels .lv-name { font: 600 1.1rem/1.3 var(--serif); color: var(--navy); }
.levels .lv-sum { color: var(--muted); font-size: .95rem; }

/* guides */
.guide-list { list-style: none; padding: 0; margin: 0 0 1.5em; display: grid; gap: 0; border-top: 1px solid var(--grid); }
.guide-list a { display: grid; grid-template-columns: 1fr auto; gap: 2px 14px; padding: 14px 4px; border-bottom: 1px solid var(--grid); text-decoration: none; color: var(--ink); }
.guide-list a:hover { background: var(--wash); }
.g-title { font: 600 1.08rem/1.3 var(--serif); color: var(--navy); grid-column: 1; }
.g-sum { grid-column: 1; color: var(--muted); font-size: .94rem; }
.g-tag { grid-column: 2; grid-row: 1 / span 2; align-self: center; font-size: .75rem; letter-spacing: .05em; text-transform: uppercase; color: var(--amber-ink); font-weight: 600; text-align: right; max-width: 11rem; }

/* checklists with progress */
.checklist-wrap { border: 1px solid var(--grid-2); background: var(--paper); margin: 1em 0 1.4em; }
.checklist-wrap .progress { display: flex; align-items: center; gap: 12px; padding: 10px 14px; background: var(--wash); border-bottom: 1px solid var(--grid); font-size: .86rem; font-weight: 600; color: var(--navy); }
.progress-track { flex: 1; height: 8px; background: var(--paper); border: 1px solid var(--grid-2); position: relative; }
.progress-fill { position: absolute; left: 0; top: 0; bottom: 0; background: var(--amber); width: 0; transition: width .2s; }
.checklist { list-style: none; margin: 0; padding: 4px 0; }
.checklist li { border-bottom: 1px solid var(--grid); margin: 0; }
.checklist li:last-child { border-bottom: 0; }
.checklist label { display: grid; grid-template-columns: 22px 1fr; gap: 10px; padding: 9px 14px; cursor: pointer; align-items: start; }
.checklist input { width: 20px; height: 20px; margin: 3px 0 0; accent-color: var(--navy); }
.checklist input:checked + span { color: var(--muted); text-decoration: line-through; text-decoration-color: var(--amber); text-decoration-thickness: 2px; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 10px 20px; border: 2px solid var(--navy); background: var(--paper); color: var(--navy); font: 600 1rem/1.2 var(--sans); text-decoration: none; cursor: pointer; border-radius: var(--radius); }
.btn:hover { background: var(--wash); color: var(--navy); }
.btn.primary { background: var(--navy); color: #fff; box-shadow: inset 0 -4px 0 var(--amber); }
.btn.primary:hover { background: var(--navy-2); color: #fff; }

/* ------------------------------------------------------------------ home */
.cover { background-color: var(--paper); background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px); background-size: 24px 24px; border-bottom: 1px solid var(--grid-2); }
.cover-in { max-width: 1180px; margin: 0 auto; padding: clamp(28px, 6vw, 72px) var(--gutter) clamp(28px, 5vw, 56px); display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr); gap: 8px 48px; align-items: stretch; }
.cover-text { display: flex; flex-direction: column; justify-content: center; background: var(--paper); padding: clamp(18px, 3vw, 32px); border: 1px solid var(--grid-2); border-top: 4px solid var(--navy); }
.cover h1 { font-size: clamp(2rem, 1.2rem + 3.2vw, 3.3rem); max-width: 18ch; margin-bottom: .5em; }
.cover .lead { margin-bottom: 0; }
.cover-side { align-self: stretch; display: flex; flex-direction: column; justify-content: space-between; gap: 18px; }
.cover-toc { background: var(--paper); border: 1px solid var(--grid-2); padding: 14px 16px 8px; }
.cover-toc ol { list-style: none; margin: 0; padding: 0; }
.cover-toc li a { display: flex; gap: 6px; align-items: baseline; padding: 5px 0; border-bottom: 1px dotted var(--grid-2); text-decoration: none; color: var(--navy); font-weight: 500; }
.cover-toc li:last-child a { border-bottom: 0; }
.cover-toc li a:hover { color: var(--link); text-decoration: underline; }
.cover-toc .cl { min-width: 1.6em; }
.cover-meta { margin: 0; border: 2px solid var(--navy); background: var(--paper); font-size: .92rem; }
.cover-meta > div { display: grid; grid-template-columns: 7.5rem 1fr; border-top: 1px solid var(--grid); }
.cover-meta > div:first-child { border-top: 0; }
.cover-meta dt { padding: 9px 12px; font-weight: 600; color: #fff; background: var(--navy); border-bottom: 1px solid var(--navy-2); }
.cover-meta dd { margin: 0; padding: 9px 12px; }
.cover-jump { display: flex; gap: 14px 22px; align-items: center; flex-wrap: wrap; margin-top: 18px; }
.home-body { max-width: 1180px; margin: 0 auto; padding: 8px var(--gutter) 40px; }
.hsec { padding: 34px 0 18px; border-bottom: 1px solid var(--grid); }
.hsec:last-child { border-bottom: 0; }
.hsec > h2, .hsec-head h2 { margin-top: 0; }
.hsec-head { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 4px 40px; align-items: end; margin-bottom: 16px; }
.hsec-head p { color: var(--muted); margin: 0 0 .6em; }
.cols-2, .split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 0 48px; }
.split > div > h2 { margin-top: 0; }
.steps { list-style: none; padding: 0; margin: 0; border: 1px solid var(--grid-2); }
.steps li { display: grid; grid-template-columns: 2.4em 1fr; gap: 10px; padding: 14px 16px; border-bottom: 1px solid var(--grid); }
.steps li:last-child { border-bottom: 0; }
.steps .cl { font-size: 1.4rem; line-height: 1.2; }
.quizlist .sub { display: inline; margin-left: 6px; }
.notice { background: var(--wash); padding: 24px 24px 12px; border: 1px solid var(--grid); margin-top: 34px; }

/* ---------------------------------------------------------- course finder */
.filter-bar { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)) auto; gap: 12px 14px; align-items: end; background: var(--wash); border: 1px solid var(--grid-2); border-top: 3px solid var(--navy); padding: 14px; margin-bottom: 14px; }
.filter-bar p { margin: 0; }
.filter-bar label { display: block; font-weight: 600; font-size: .85rem; color: var(--navy); margin-bottom: 4px; }
select, input[type="search"] { width: 100%; min-height: 44px; padding: 8px 10px; border: 1px solid #8796A8; background: var(--paper); font: inherit; font-size: .95rem; color: var(--ink); border-radius: var(--radius); }
.fb-actions { display: flex; gap: 12px; align-items: center; }
.result-count { font-size: .95rem; }

/* ------------------------------------------------------------------ quiz */
.practice-flag { border: 1px solid var(--amber); background: var(--amber-soft); padding: 10px 14px; font-size: .95rem; }
.quiz { max-width: var(--measure); }
.scorebar { position: sticky; top: 0; z-index: 5; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; background: var(--navy); color: #fff; padding: 10px 14px; margin-bottom: 16px; font-weight: 600; font-variant-numeric: tabular-nums; }
.scorebar[hidden] { display: none; }
.sb-label { text-transform: uppercase; font-size: .75rem; letter-spacing: .1em; color: #C9D6E6; }
.sb-n { color: var(--amber); font-size: 1.1rem; }
.sb-sep { color: #5C7899; }
.sb-reset { margin-left: auto; background: transparent; color: #fff; border: 1px solid #5C7899; padding: 6px 12px; font: inherit; font-size: .85rem; cursor: pointer; min-height: 36px; }
.sb-reset:hover { border-color: #fff; }
.qq { border: 1px solid var(--grid-2); padding: 0 0 6px; margin: 0 0 18px; background: var(--paper); min-width: 0; }
.qq legend { float: left; width: 100%; padding: 14px 16px 6px; font-weight: 600; color: var(--navy); line-height: 1.45; }
.qq legend .cl { min-width: 2.2em; }
.qq legend + * { clear: both; }
.opts { list-style: none; margin: 0; padding: 4px 16px 0; }
.opts li { margin: 0 0 6px; }
.opts label { display: grid; grid-template-columns: 20px 1.6em 1fr; gap: 8px; align-items: start; padding: 9px 10px; border: 1px solid var(--grid); cursor: pointer; }
.opts label:hover { border-color: var(--grid-2); background: var(--wash); }
.opts input { margin: 4px 0 0; width: 18px; height: 18px; accent-color: var(--navy); }
.opts .ol { font-weight: 700; color: var(--muted); }
.opts label.correct { border-color: var(--ok); background: var(--ok-soft); }
.opts label.chosen-wrong { border-color: var(--bad); background: var(--bad-soft); }
.fb { margin: 6px 16px 4px; font-weight: 600; min-height: 1px; }
.qq.is-right .fb { color: var(--ok); }
.qq.is-wrong .fb { color: var(--bad); }
.qq.is-right { border-left: 4px solid var(--ok); }
.qq.is-wrong { border-left: 4px solid var(--bad); }
.why { margin: 4px 16px 8px; font-size: .95rem; }
.why summary { cursor: pointer; color: var(--link); font-weight: 600; padding: 6px 0; }
.why .ref { color: var(--muted); font-size: .85rem; }
.scorebox { border: 2px solid var(--navy); padding: 14px 18px; margin: 0 0 18px; display: flex; gap: 18px; align-items: center; flex-wrap: wrap; }
.scorebox p { margin: 0; }
.score-n { font: 600 2rem/1 var(--serif); color: var(--navy); }
.quiz-actions { margin-top: 10px; }

/* glossary / faq */
.az ul { list-style: none; padding: 0; margin: 0 0 18px; display: flex; flex-wrap: wrap; border: 1px solid var(--grid-2); }
.az li { border-right: 1px solid var(--grid); }
.az a { display: block; min-width: 40px; text-align: center; padding: 8px 6px; font-weight: 600; text-decoration: none; }
.az a:hover { background: var(--amber-soft); }
h2.letter { font-size: 1.6rem; border-bottom: 2px solid var(--navy); padding-bottom: 4px; margin-top: 1.4em; }
.gloss { margin: 0; }
.gloss > div { display: grid; grid-template-columns: minmax(9rem, 30%) 1fr; gap: 4px 20px; padding: 12px 0; border-bottom: 1px solid var(--grid); scroll-margin-top: 16px; }
.gloss > div:target { background: var(--amber-soft); box-shadow: -8px 0 0 var(--amber-soft), 8px 0 0 var(--amber-soft); }
.gloss dt { font-weight: 600; color: var(--navy); }
.gloss dd { margin: 0; }
.gloss dd p:last-child { margin-bottom: 0; }
.faq details { border-bottom: 1px solid var(--grid); }
.faq details:first-child { border-top: 2px solid var(--navy); }
.faq summary { cursor: pointer; padding: 14px 4px; font: 600 1.08rem/1.35 var(--serif); color: var(--navy); list-style: none; display: grid; grid-template-columns: 3em 1fr 1.2em; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--sans); color: var(--amber-ink); font-weight: 700; text-align: right; }
.faq details[open] summary::after { content: "–"; }
.faq .prose { padding: 0 4px 6px 3em; }

/* sources / related */
.sources { margin-top: 40px; padding-top: 6px; border-top: 2px solid var(--navy); font-size: .88rem; color: var(--muted); }
.sources h2 { font-size: 1.05rem; margin-top: 14px; }
.sources ol { padding-left: 1.4em; word-break: break-word; }
.related { margin-top: 36px; }
.related h2 { font-size: 1.2rem; }
.scheme-sum { font-size: .93rem; }

/* ---------------------------------------------------------------- footer */
.site-foot { background: var(--navy); color: #DCE5F0; border-top: 4px solid var(--amber); margin-top: 0; }
.foot-in { max-width: 1440px; margin: 0 auto; padding: 36px var(--gutter) 28px; display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 10px 48px; font-size: .92rem; }
.foot-name { font: 600 1.3rem/1.2 var(--serif); color: #fff; margin-bottom: .4em; }
.site-foot a { color: #fff; }
.site-foot a:hover { color: var(--amber); }
.foot-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 0 24px; }
.foot-nav ul { list-style: none; padding: 0; margin: 0; }
.foot-nav li { padding: 4px 0; }
.foot-note, .foot-copy { grid-column: 1 / -1; margin: 0; padding-top: 12px; border-top: 1px solid #2B4A70; color: #C3D0E0; }
.foot-copy { border-top: 0; padding-top: 0; }

/* kit photo credits page */
.kit-credits { padding: 0; }

/* ------------------------------------------------------------ responsive */
@media (max-width: 1199px) {
  .shell.has-toc { grid-template-columns: var(--side) minmax(0, 1fr); grid-template-areas: "side main"; }
  .toc { display: none; }
}
@media (max-width: 700px) {
  .data.courses, .data.courses tbody, .data.courses tr, .data.courses th, .data.courses td, .data.stack, .data.stack tbody, .data.stack tr, .data.stack th, .data.stack td { display: block; width: 100%; }
  .data.courses thead, .data.stack thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .data.courses tr, .data.stack tr { border-bottom: 2px solid var(--grid-2); padding: 10px 0; }
  .data.courses tbody th, .data.stack tbody th { min-width: 0; border: 0; padding: 4px 12px 6px; font-size: 1rem; }
  .data.courses td, .data.stack td { border: 0; padding: 3px 12px; display: grid; grid-template-columns: 7.5rem 1fr; gap: 8px; white-space: normal; }
  .data.courses td + td, .data.courses th + td, .data.stack td + td, .data.stack th + td { border-left: 0; }
  .data.courses td::before, .data.stack td::before { content: attr(data-label); font-size: .78rem; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; padding-top: 2px; }
  .data.courses td > span > .sub, .data.stack td > span > .sub { display: block; margin: 0; }
  .table-wrap:has(.data.courses), .table-wrap:has(.data.stack) { overflow: visible; }
  .data.courses td > *, .data.stack td > * { justify-self: start; }
}
@media (max-width: 1040px) {
  .top-nav { display: none; }
  .menu { display: block; }
}
@media (max-width: 899px) {
  :root { --gutter: 16px; }
  body { font-size: 1rem; }
  .shell, .shell.has-toc { grid-template-columns: minmax(0, 1fr); grid-template-areas: "main" "side"; }
  .shell > main { padding: 18px var(--gutter) 40px; }
  .side { border-right: 0; border-top: 4px solid var(--navy); padding: 22px var(--gutter) 30px; }
  .side-sec ul { columns: 2 12rem; column-gap: 16px; }
  .side-sec li { break-inside: avoid; }
  .cover-in { grid-template-columns: minmax(0, 1fr); }
  .cover-side { margin-top: 18px; }
  .cover-toc { display: none; }
  .hsec-head, .cols-2, .split { grid-template-columns: minmax(0, 1fr); }
  .steps { margin-top: 10px; }
  .filter-bar { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .fb-actions { grid-column: 1 / -1; }
  .foot-in { grid-template-columns: minmax(0, 1fr); }
  .levels li a { grid-template-columns: 2.8em 1fr; }
  .levels .lv-sum { grid-column: 2; }
}
@media (max-width: 560px) {
  .doc-meta > div, .cover-meta > div { grid-template-columns: 1fr; }
  .doc-meta dt { border-right: 0; padding-bottom: 4px; }
  .cover-meta dt { padding-bottom: 6px; }
  .gloss > div { grid-template-columns: 1fr; }
  .filter-bar { grid-template-columns: minmax(0, 1fr); }
  .guide-list a { grid-template-columns: 1fr; }
  .g-tag { grid-column: 1; grid-row: auto; text-align: left; }
  .faq summary { grid-template-columns: 2.6em 1fr 1em; }
  .faq .prose { padding-left: 4px; }
  .data.courses tbody th { min-width: 12rem; }
  .matrix tbody th { min-width: 8.6rem; padding: 6px 8px; }
  .matrix .topic { font-size: .72rem; }
  .brand-sub { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}
@media print {
  .site-head, .side, .toc, .site-foot, .scorebar, .quiz-actions { display: none !important; }
  .shell { display: block; }
  .why { display: block; }
}
.prose .checklist { padding-left: 0; }
.credit-list { list-style: none; padding: 0; margin: 0; max-width: var(--measure); }
.credit-list li { display: grid; grid-template-columns: 200px 1fr; gap: 16px; padding: 14px 0; border-bottom: 1px solid var(--grid); align-items: start; }
.credit-list img { width: 200px; height: auto; border: 1px solid var(--grid); }
.credit-list .photo-credit { font-size: .9rem; opacity: 1; }
@media (max-width: 560px) { .credit-list li { grid-template-columns: 1fr; } }
.home-body .levels { max-width: none; }
.home-body .levels li a { grid-template-columns: 3.2em minmax(10rem, 16rem) 1fr; }
@media (max-width: 899px) { .home-body .levels li a { grid-template-columns: 2.8em 1fr; } }