/* library/assets/library.css
 * The lesson library's one stylesheet. Tokens and registers from DESIGN.md
 * (Lichen & Bark): bark ground for the bar, moss for the one action per view,
 * cool stone neutrals, Bodoni Moda headlines, Source Serif 4 reading,
 * IBM Plex Sans for UI, IBM Plex Mono for labels. Plain semantic HTML, no
 * framework; works without JavaScript and prints cleanly. */

:root {
  --bark: #1c211c; --moss: #3c6b25; --glow: #8ed13c;
  --ink: #33362f; --muted: #616b5c; --border: #e3e1d9; --surface: #f5f4f0;
  --violet: #7c3aed; --teal: #0f766e; --blue: #2563eb; --green: #15803d;
  --amber: #b45309; --red: #b91c1c;
  --display: "Bodoni Moda", "Source Serif 4", Georgia, serif;
  --reading: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --measure: 34.5rem;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: #fff; color: var(--ink); font: 400 1rem/1.5 var(--sans); }
a { color: var(--moss); }
a:hover { color: var(--bark); }
::selection { background: color-mix(in srgb, var(--glow) 30%, transparent); }
img { max-width: 100%; height: auto; }

/* ---------------------------------------------------------------- bar */
.bar { position: sticky; top: 0; z-index: 5; display: flex; align-items: center; gap: 1rem;
  padding: 0 1.5rem; height: 3.5rem; background: var(--bark); color: rgba(255,255,255,.75); }
.bar a { color: rgba(255,255,255,.8); text-decoration: none; }
.bar a:hover { color: #fff; }
.bar-home { display: flex; align-items: center; gap: .5rem; font-weight: 600; white-space: nowrap; }
.spore { width: 1.4rem; height: 1.4rem; fill: var(--glow); }
.crumbs { flex: 1; min-width: 0; display: flex; gap: .4rem; font-size: .875rem; overflow: hidden; white-space: nowrap; }
.crumbs > :last-child { overflow: hidden; text-overflow: ellipsis; color: #fff; }
.crumbs .sep { opacity: .4; }
.version { position: relative; font: 600 .72rem/1 var(--mono); letter-spacing: .05em; }
.version summary { cursor: pointer; list-style: none; padding: .45rem .6rem; border: 1px solid rgba(255,255,255,.14); border-radius: 6px; color: #fff; }
.version summary::-webkit-details-marker { display: none; }
.version ul { position: absolute; right: 0; top: 2.3rem; margin: 0; padding: .35rem; list-style: none; min-width: 10rem;
  background: #fff; border: 1px solid var(--border); border-radius: 8px; box-shadow: 0 8px 28px rgba(0,0,0,.09); }
.version li a { display: block; padding: .4rem .55rem; border-radius: 6px; color: var(--ink); }
.version li a:hover, .version li a[aria-current] { background: var(--surface); color: var(--bark); }
.version li span { color: var(--moss); font-weight: 700; }

/* ---------------------------------------------------------------- layout */
main { max-width: 1060px; margin: 0 auto; padding: 2.5rem 1.5rem 4rem; }
.lesson article { max-width: var(--measure); margin: 0 auto; }
.index { max-width: 1100px; }
h1, h2, h3 { font-family: var(--display); font-weight: 600; color: var(--bark); text-wrap: balance; }
h1 { font-size: clamp(1.9rem, 4vw, 2.75rem); line-height: 1.14; letter-spacing: -.015em; margin: .3rem 0 .8rem; }
.teaser { font: italic 400 1.2rem/1.55 var(--reading); color: var(--muted); max-width: 52ch; margin: 0 0 1.6rem; }
.specimen { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; margin: 0;
  padding-bottom: .5rem; border-bottom: 1px solid var(--border);
  font: 700 .72rem/1.4 var(--mono); letter-spacing: .05em; text-transform: uppercase; color: var(--muted); }
.durations { display: flex; gap: 1rem; font-variant-numeric: tabular-nums; }
.old-version { margin: 0 auto 1.5rem; max-width: var(--measure); padding: .7rem 1rem; border: 1px solid var(--border);
  border-radius: 8px; background: var(--surface); font-size: .875rem; }

/* ---------------------------------------------------------------- invitation */
.invite { margin: 1.5rem 0 2rem; padding: 1.2rem 1.35rem; border: 1px solid color-mix(in srgb, var(--moss) 35%, var(--border));
  border-radius: 12px; background: color-mix(in srgb, var(--moss) 6%, #fff); }
.invite p { margin: 0 0 .6rem; }
.invite-head { font: 600 1.125rem/1.35 var(--sans); color: var(--bark); }
.invite-actions { display: flex; gap: .6rem; flex-wrap: wrap; margin: .9rem 0 0 !important; }
.invite-closing { margin-top: 3rem; }
.btn { display: inline-block; padding: .62rem 1.3rem; border-radius: 8px; background: var(--moss); color: #fff;
  font-weight: 700; text-decoration: none; }
.btn:hover { background: color-mix(in srgb, var(--moss) 90%, #000); color: #fff; }
.btn-quiet { background: #fff; color: var(--bark); border: 1px solid var(--border); }
.btn-quiet:hover { background: var(--surface); color: var(--bark); }

/* ---------------------------------------------------------------- modes */
.modes { display: flex; gap: .25rem; margin: 0 0 1.5rem; border-bottom: 1px solid var(--border); overflow-x: auto; }
.modes a { padding: .7rem .95rem; font-weight: 600; font-size: .95rem; color: var(--muted); text-decoration: none;
  border-bottom: 3px solid transparent; margin-bottom: -1px; white-space: nowrap; }
.modes a:hover { color: var(--bark); }
.modes a[aria-selected="true"] { color: var(--bark); border-bottom-color: var(--moss); }
.mode { scroll-margin-top: 4.5rem; }
.js .mode[hidden] { display: none; }
.mode-band { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; margin: 2.5rem 0 1rem;
  padding: .6rem .9rem; border-left: 4px solid var(--moss);
  background: linear-gradient(90deg, color-mix(in srgb, var(--moss) 9%, #fff), #fff 70%); }
.mode-band h2 { margin: 0; font-size: clamp(1.6rem, 2.6vw, 2rem); line-height: 1.18; }
.mode-band span { font: 700 .72rem/1 var(--mono); letter-spacing: .05em; text-transform: uppercase; color: var(--muted); }
.js .mode-band { margin-top: 0; }
.mode-summaries { display: grid; gap: .75rem; margin-top: 1.5rem; }
.mode-summary { padding: .9rem 1rem; border: 1px solid var(--border); border-radius: 12px; }
.mode-summary p { margin: 0; }
.mode-name { font: 700 .72rem/1.4 var(--mono) !important; letter-spacing: .05em; text-transform: uppercase; margin-bottom: .3rem !important; }

/* ---------------------------------------------------------------- prose */
.prose { font: 400 1.1875rem/1.72 var(--reading); font-kerning: normal; hanging-punctuation: first last;
  font-variant-ligatures: common-ligatures contextual; }
.prose p, .prose ul, .prose ol { margin: 0 0 1.15em; }
.prose h2 { font-size: clamp(1.45rem, 2.1vw, 1.8rem); line-height: 1.22; margin: 2.2em 0 .6em; }
.prose h3 { font-size: 1.22rem; line-height: 1.3; margin: 2em 0 .5em; padding-top: .7em; border-top: 1px solid var(--border); }
.prose hr + h3 { border-top: 0; padding-top: 0; margin-top: 0; }
.prose h4 { font: 700 1.125rem/1.35 var(--sans); color: var(--bark); margin: 1.6em 0 .4em; }
.prose hr { border: 0; height: 1px; margin: 2.4em 0; background: linear-gradient(90deg, transparent, var(--border), transparent); }
.prose img { display: block; margin: 1.5em 0 .5em; border: 1px solid var(--border); border-radius: 8px; }
.prose blockquote { margin: 1.5em 0; padding: 0 0 0 1.2em; font-style: italic; color: var(--ink); position: relative; }
.prose blockquote::before { content: "\201C"; position: absolute; left: -.35em; top: -.2em; font: 600 2.4rem/1 var(--display); color: var(--border); }
.prose table { width: 100%; border-collapse: collapse; font: 400 .875rem/1.45 var(--sans); margin: 1.5em 0; display: block; overflow-x: auto; }
.prose th { text-align: left; background: var(--surface); font: 700 .72rem/1.3 var(--mono); letter-spacing: .05em; text-transform: uppercase; }
.prose th, .prose td { padding: .55rem .7rem; border-bottom: 1px solid var(--border); vertical-align: top; }
.prose code { font: .9em var(--mono); background: var(--surface); padding: .05em .3em; border-radius: 4px; }
.prose details { margin: 1.2em 0; border: 1px solid var(--border); border-radius: 12px; overflow: hidden; }
.prose summary { cursor: pointer; padding: .7rem 1rem; background: var(--surface); font: 600 1rem/1.4 var(--sans); color: var(--bark); }
.prose details > :not(summary) { margin-left: 1rem; margin-right: 1rem; }
.prose details[open] > :last-child { margin-bottom: 1rem; }

/* callouts and case studies: the reader's own registers */
.callout, .case-study { margin: 1.6em 0; padding: 1rem 1.15rem; border-radius: 12px; font: 400 1rem/1.55 var(--sans); }
.callout p, .case-study p { margin: 0 0 .6em; }
.callout > :last-child, .case-study > :last-child { margin-bottom: 0; }
.callout-label, .case-study-label { font: 700 .72rem/1.3 var(--mono) !important; letter-spacing: .05em; text-transform: uppercase; }
.callout-title, .case-study-name { font: 600 1.125rem/1.35 var(--display) !important; color: var(--bark); }
.callout { --c: var(--blue); background: color-mix(in srgb, var(--c) 6%, #fff); border: 1px solid color-mix(in srgb, var(--c) 30%, transparent); }
.callout .callout-label { color: var(--c); }
.callout-tip { --c: var(--green); } .callout-important { --c: var(--violet); }
.callout-warning { --c: var(--amber); } .callout-caution { --c: var(--red); }
.case-study { background: var(--surface); border: 1px solid var(--border); border-top: 2px solid var(--bark);
  font: 400 1.1875rem/1.72 var(--reading); }
.case-study .case-study-label { color: var(--muted); }

/* ---------------------------------------------------------------- interactive cards */
.lms { --c: var(--moss); margin: 1.8em 0; padding: 1rem 1.15rem 1.05rem; border-radius: 12px; background: #fff;
  border: 1.5px dashed color-mix(in srgb, var(--c) 55%, transparent); font: 400 1rem/1.55 var(--sans); scroll-margin-top: 4.5rem; }
.lms[data-type="reflection_response"], .lms[data-type="reflection_question"] { --c: var(--violet); }
.lms[data-type="recall"] { --c: var(--teal); }
.lms[data-type="session_response"] { --c: var(--blue); }
.lms p { margin: 0 0 .55rem; }
.lms-label { font: 700 .72rem/1.3 var(--mono) !important; letter-spacing: .05em; text-transform: uppercase; color: var(--c); }
.lms-prompt { font: 400 1.1875rem/1.55 var(--reading) !important; color: var(--bark); }
.lms-note, .lms-from { color: var(--muted); font-size: .875rem; }
.lms-work { font-weight: 700; font-size: .875rem; color: var(--c); }
.resource-link { font: 400 1rem/1.5 var(--sans); }

/* ---------------------------------------------------------------- index pages */
.modules { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; margin-top: 2rem; }
.module h2 { font-size: clamp(1.45rem, 2.1vw, 1.8rem); margin: 0 0 .8rem; padding-bottom: .4rem; border-bottom: 1px solid var(--border); }
.lesson-list, .releases, .courses { list-style: none; margin: 0; padding: 0; }
.lesson-list li, .courses li { padding: .9rem 0 1rem; border-bottom: 1px solid var(--border); }
.lesson-list a, .courses a { display: flex; gap: .6rem; text-decoration: none; color: var(--bark); }
.lesson-title { font: 600 1.125rem/1.35 var(--sans); }
.lesson-n { font: 700 .8rem/1.9 var(--mono); color: var(--muted); min-width: 1.2rem; font-variant-numeric: tabular-nums; }
.lesson-list p, .courses p { margin: .3rem 0 0 1.8rem; font-size: .95rem; }
.courses p { margin-left: 0; }
.meta { color: var(--muted); font-size: .875rem !important; }
.releases li { padding: .8rem 0; border-bottom: 1px solid var(--border); }
.releases a { font: 700 1rem var(--mono); }
.releases .meta { margin-left: .6rem; }
.changes { margin: .25rem 0 0; color: var(--ink); font-size: .95rem; }
.pill { font: 700 .7rem var(--mono); letter-spacing: .05em; text-transform: uppercase; color: var(--moss);
  background: color-mix(in srgb, var(--moss) 10%, #fff); padding: .1rem .5rem; border-radius: 20px; }
.foot { margin-top: 3.5rem; padding-top: 1rem; border-top: 1px solid var(--border); font-size: .875rem; color: var(--muted); }
.foot p { margin: 0 0 .35rem; }

@media (max-width: 640px) {
  .bar { padding: 0 1rem; gap: .6rem; } .bar-home span { display: none; }
  main { padding: 1.5rem 1rem 3rem; }
}
@media print {
  .bar, .modes, .version, .invite-actions, .lms-work { display: none !important; }
  .js .mode[hidden] { display: block !important; }
  body { font-size: 11pt; } main { padding: 0; }
  .prose { font-size: 11pt; } .prose img { break-inside: avoid; }
  .invite { border: 1px solid #999; background: none; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 9pt; color: #555; }
}