/* ==========================================================================
   Learn — articles, hubs and common questions on every public site.
   Loads after components.css. Owned by the kit; markup from sites/learn/engine.mjs.

   Direction (docs/plans/2026-11-09-learn-topic-map.md, research in the program folder):
   ink on warm paper, one visible grid, hierarchy by size and space in one family,
   hairlines instead of cards, colour for three jobs only: the product mark, the
   step numbers and the one action. No motion beyond the kit's hover and focus.
   ========================================================================== */

.learn {
  --learn-accent: var(--kol-accent);          /* fill, always with dark ink on it */
  --learn-accent-on: #17181a;
  --learn-ink: #7a4f00;                        /* the accent hue dark enough for text on paper (6.5:1) */
  --learn-wash: var(--kol-accent-quiet);
  --learn-measure: 68ch;
  --learn-body: 1.0625rem;
  --learn-leading: 1.65;
  padding-block: clamp(24px, 4vw, 56px) clamp(48px, 8vw, 96px);
}
.learn[data-product="kolchat"] {
  --learn-accent: #39c862;
  --learn-ink: #0b7a35;                        /* 5.0:1 on paper */
  --learn-wash: #e6f5ea;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .learn { --learn-ink: #ffc247; }
  :root:not([data-theme="light"]) .learn[data-product="kolchat"] { --learn-accent: #5ce07a; --learn-ink: #5ce07a; --learn-wash: #14261a; }
}
:root[data-theme="dark"] .learn { --learn-ink: #ffc247; }
:root[data-theme="dark"] .learn[data-product="kolchat"] { --learn-accent: #5ce07a; --learn-ink: #5ce07a; --learn-wash: #14261a; }

/* Scripts read differently at the same size: Hebrew and Arabic get a little more size and air. */
.learn:lang(he) { --learn-body: 1.125rem; --learn-leading: 1.7; --learn-measure: 60ch; }
.learn:lang(ar) { --learn-body: 1.125rem; --learn-leading: 1.85; --learn-measure: 54ch; }

.learn :where(h1, h2, h3) { text-wrap: balance; }
.learn :where(p, li, dd) { text-wrap: pretty; }
.learn :where(h2, h3, section)[id] { scroll-margin-top: calc(var(--kol-header-h) + 24px); }

/* ---- The product mark: an 8px square of the accent before the eyebrow ---- */
.learn-eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 var(--kol-space-4, 16px);
  font-size: var(--kol-text-sm);
  font-weight: 600;
  color: var(--kol-ink-muted);
}
.learn-eyebrow:lang(en), .learn-eyebrow:lang(es), .learn-eyebrow:lang(fr), .learn-eyebrow:lang(de),
.learn-eyebrow:lang(pt), .learn-eyebrow:lang(it), .learn-eyebrow:lang(ru) {
  letter-spacing: var(--kol-tracking-wide);
  text-transform: uppercase;
  font-size: var(--kol-text-xs);
}
.learn-mark {
  inline-size: 8px;
  block-size: 8px;
  background: var(--learn-accent);
  flex: none;
}

/* ---- Article grid: meta in the narrow column, prose at a reading measure ---- */
.learn-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0 var(--kol-gap);
}
.learn-crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 0;
  margin: 0 0 clamp(20px, 3vw, 40px);
  padding: 0;
  list-style: none;
  font-size: var(--kol-text-sm);
  color: var(--kol-ink-muted);
}
.learn-crumbs li + li::before {
  content: "/";
  margin-inline: 10px;
  color: var(--kol-ink-faint);
}
.learn-crumbs a { color: inherit; text-decoration: none; }
.learn-crumbs a:hover { color: var(--kol-ink); text-decoration: underline; text-underline-offset: 3px; }

.learn-head { max-inline-size: 46rem; }
.learn-head h1, .learn-hub-head h1 {
  margin: 0;
  font-size: clamp(1.875rem, 1.2rem + 2.6vw, 2.75rem);
  line-height: 1.1;
  font-weight: 600;
  letter-spacing: var(--kol-tracking-tight);
  color: var(--kol-ink);
}
.learn-head h1:is(:lang(he), :lang(ar)), .learn-hub-head h1:is(:lang(he), :lang(ar)) { letter-spacing: 0; line-height: 1.2; }
.learn-dek {
  margin: var(--kol-space-4, 16px) 0 0;
  max-inline-size: 40em;
  font-size: var(--kol-text-lg);
  line-height: 1.5;
  color: var(--kol-ink-muted);
}

.learn-meta {
  margin-block: clamp(24px, 4vw, 40px) 0;
  padding-block: 16px;
  border-block: 1px solid var(--kol-line);
  font-size: var(--kol-text-sm);
  color: var(--kol-ink-muted);
}
.learn-meta dl { display: flex; flex-wrap: wrap; gap: 12px 32px; margin: 0; }
.learn-meta dt { font-weight: 600; color: var(--kol-ink); }
.learn-meta dd { margin: 2px 0 0; }
.learn-toc { margin-top: 16px; }
.learn-toc h2 {
  margin: 0 0 8px;
  font-size: var(--kol-text-sm);
  font-weight: 600;
  color: var(--kol-ink);
}
.learn-toc ol { margin: 0; padding-inline-start: 1.25em; display: grid; gap: 6px; }
.learn-toc a { color: var(--kol-ink-muted); text-decoration: none; }
.learn-toc a:hover { color: var(--kol-ink); text-decoration: underline; text-underline-offset: 3px; }

@media (min-width: 1024px) {
  .learn-grid { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .learn-crumbs, .learn-head { grid-column: 4 / span 8; }
  .learn-meta {
    grid-column: 1 / span 3;
    grid-row: 3 / span 2;
    align-self: start;
    position: sticky;
    top: calc(var(--kol-header-h) + 24px);
    margin-top: 48px;
    border-block-end: 0;
  }
  .learn-meta dl { display: grid; gap: 16px; }
  .learn-body { grid-column: 4 / span 8; }
}

/* ---- The prose ---- */
.learn-body {
  max-inline-size: var(--learn-measure);
  margin-top: clamp(24px, 4vw, 48px);
  font-size: var(--learn-body);
  line-height: var(--learn-leading);
  color: var(--kol-ink);
}
.learn-body > :first-child { margin-top: 0; }
.learn-section { margin-top: clamp(40px, 5vw, 56px); }
.learn-section h2 {
  margin: 0 0 16px;
  font-size: clamp(1.375rem, 1.1rem + 0.9vw, 1.75rem);
  line-height: 1.25;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.learn-section h2:is(:lang(he), :lang(ar)) { letter-spacing: 0; }
.learn-section h3 { margin: 28px 0 8px; font-size: 1.1875rem; line-height: 1.35; font-weight: 600; }
.learn-body p { margin: 0 0 1em; }
.learn-body a:not(.kol-btn) {
  color: var(--kol-ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
.learn-body a:not(.kol-btn):hover { text-decoration-color: var(--learn-ink); text-decoration-thickness: 2px; }
.learn-body strong { font-weight: 600; }
.learn-body code, .learn-body kbd {
  font-family: var(--kol-font-mono);
  font-size: 0.875em;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--kol-sunk);
  color: var(--kol-ink);
  unicode-bidi: isolate;
}
.learn-body kbd { border: 1px solid var(--kol-line-strong); background: var(--kol-surface); }
.learn-only {
  margin: -8px 0 16px;
  font-size: var(--kol-text-sm);
  color: var(--kol-ink-muted);
}

.learn-list { margin: 0 0 1em; padding-inline-start: 1.25em; }
.learn-list li { margin-bottom: 0.4em; }
.learn-list li::marker { color: var(--kol-ink-faint); }

/* Steps: the number sits in a square of the accent, the text keeps the reading measure. */
.learn-steps {
  counter-reset: learn-step;
  margin: 0 0 1.25em;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}
.learn-steps li {
  counter-increment: learn-step;
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
}
.learn-steps li::before {
  content: counter(learn-step);
  display: grid;
  place-items: center;
  inline-size: 28px;
  block-size: 28px;
  margin-top: 0.1em;
  border-radius: 4px;
  background: var(--learn-accent);
  color: var(--learn-accent-on);
  font-size: 0.8125rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* Two callouts only. A Note is quiet; a Warning names a consequence and is drawn in ink. */
.learn-callout {
  margin: 0 0 1.25em;
  padding: 14px 18px;
  border-inline-start: 3px solid var(--learn-accent);
  background: var(--kol-sunk);
  border-start-end-radius: 6px;
  border-end-end-radius: 6px;
}
.learn-callout p { margin: 0; }
.learn-callout strong { margin-inline-end: 6px; }
.learn-callout-warning { border-inline-start-color: var(--kol-ink); }

.learn-table {
  margin: 0 0 1.5em;
  overflow-x: auto;
  border-block: 1px solid var(--kol-line);
}
.learn-table table { inline-size: 100%; border-collapse: collapse; font-size: 0.9375em; font-variant-numeric: tabular-nums; }
.learn-table caption { padding: 10px 0; text-align: start; font-size: var(--kol-text-sm); color: var(--kol-ink-muted); }
.learn-table th, .learn-table td { padding: 10px 12px; text-align: start; vertical-align: top; border-top: 1px solid var(--kol-line); }
.learn-table thead th { border-top: 0; font-size: var(--kol-text-sm); font-weight: 600; color: var(--kol-ink-muted); }
.learn-table tbody th { font-weight: 600; }

/* Figures: line diagrams in the page's own colours, or a real capture. */
.learn-figure { margin: 0 0 clamp(32px, 4vw, 48px); }
.learn-figure img { display: block; inline-size: 100%; block-size: auto; border: 1px solid var(--kol-line); border-radius: 10px; }
.learn-figure svg { display: block; inline-size: 100%; block-size: auto; }
/* On a phone the drawing keeps a readable size and scrolls sideways in its own box, never the page. */
.learn-diagram { overflow-x: auto; }
@media (max-width: 640px) { .learn-diagram svg { min-inline-size: 540px; } }
.learn-figure figcaption { margin-top: 10px; font-size: var(--kol-text-sm); color: var(--kol-ink-muted); }
.learn-figure-diagram {
  padding: clamp(16px, 3vw, 28px);
  border: 1px solid var(--kol-line);
  border-radius: 10px;
  background: var(--kol-surface);
}
.d-line { stroke: var(--kol-ink-muted); stroke-width: 1.5; fill: none; vector-effect: non-scaling-stroke; }
.d-thin { stroke: var(--kol-line-strong); stroke-width: 1; fill: none; vector-effect: non-scaling-stroke; }
.d-dash { stroke-dasharray: 4 4; }
.d-box { fill: var(--kol-paper); stroke: var(--kol-ink-muted); stroke-width: 1.5; vector-effect: non-scaling-stroke; }
.d-key { fill: var(--learn-accent); stroke: none; }
.d-key-line { stroke: var(--learn-ink); stroke-width: 2; fill: none; vector-effect: non-scaling-stroke; }
.d-text { fill: var(--kol-ink); font-family: var(--kol-font-sans); font-size: 14px; }
.d-label { fill: var(--kol-ink-muted); font-family: var(--kol-font-sans); font-size: 12.5px; }
/* A halo in the panel colour keeps labels readable where they cross a line. */
.d-text, .d-label { paint-order: stroke; stroke: var(--kol-surface); stroke-width: 5px; stroke-linejoin: round; }
.d-strong { font-weight: 600; }

/* Limits: the honest part, set like the rest, under its own heading. */
.learn-limits h2::before {
  content: "";
  display: inline-block;
  inline-size: 8px;
  block-size: 8px;
  margin-inline-end: 12px;
  vertical-align: 0.2em;
  background: var(--kol-ink);
}

/* The one action at the end. */
.learn-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 24px;
  margin-top: clamp(40px, 5vw, 56px);
  padding-block: 24px;
  border-block: 1px solid var(--kol-line);
}
.learn-next p { margin: 0; max-inline-size: 34em; color: var(--kol-ink-muted); font-size: var(--kol-text-base); }

/* Related: a ruled list, no cards. */
.learn-related { margin-top: clamp(40px, 5vw, 56px); }
.learn-related h2, .learn-start h2 {
  margin: 0 0 8px;
  font-size: var(--kol-text-sm);
  font-weight: 600;
  color: var(--kol-ink-muted);
}
.learn-related ul, .learn-index { margin: 0; padding: 0; list-style: none; }
.learn-related li, .learn-index li { padding-block: 14px; border-top: 1px solid var(--kol-line); }
.learn-related a, .learn-index a {
  font-weight: 600;
  color: var(--kol-ink);
  text-decoration: none;
}
.learn-related a:hover, .learn-index a:hover { text-decoration: underline; text-decoration-color: var(--learn-ink); text-underline-offset: 3px; }
.learn-related p, .learn-index p { margin: 4px 0 0; font-size: var(--kol-text-sm); line-height: 1.5; color: var(--kol-ink-muted); }

/* ---- Hub ---- */
.learn-hub-head { max-inline-size: 46rem; margin-bottom: clamp(32px, 5vw, 64px); }
.learn-start { margin-bottom: clamp(40px, 5vw, 72px); }
.learn-index-numbered { counter-reset: learn-start; }
.learn-index-numbered li { counter-increment: learn-start; display: grid; grid-template-columns: 2.5em minmax(0, 1fr); column-gap: 8px; }
.learn-index-numbered li::before {
  content: counter(learn-start, decimal-leading-zero);
  grid-row: span 2;
  font-variant-numeric: tabular-nums;
  color: var(--kol-ink-faint);
  font-weight: 600;
}
.learn-index li[data-product="kolchat"] > a::after {
  content: "";
  display: inline-block;
  inline-size: 6px;
  block-size: 6px;
  margin-inline-start: 10px;
  vertical-align: 0.2em;
  background: #39c862;
}
.learn-topic { padding-top: 8px; margin-bottom: clamp(32px, 4vw, 56px); }
.learn-topic > h2 {
  margin: 0 0 8px;
  font-size: var(--kol-text-xl);
  line-height: 1.25;
  font-weight: 600;
}
@media (min-width: 900px) {
  .learn-start ol { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: var(--kol-gap); }
  .learn-topic { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 0 var(--kol-gap); border-top: 1px solid var(--kol-line-strong); padding-top: 20px; }
  .learn-topic > h2 { grid-column: 1 / span 3; font-size: var(--kol-text-lg); }
  .learn-topic > .learn-index { grid-column: 4 / span 9; }
  .learn-topic .learn-index li:first-child { border-top: 0; padding-top: 0; }
}

@media print {
  .learn-meta, .learn-next, .learn-related, .learn-crumbs { display: none; }
  .learn-body { max-inline-size: none; }
}