/* osteonlabs.com. Palette: "Toluidine", after the toluidine blue stain used on bone sections
   (owner decision 2026-10-17). A cool mineral field, ink structure, a teal stain for the
   interface; amber stays only as the lacunae, the cells, in the mark. Ink bands (.ink) redefine
   the same tokens, so every component inside them follows. No external requests. */
:root {
  --field: #EEF1EF; --ink: #17191E; --muted: #4E5856; --rule: #CBD3CF;
  --accent: #136872; --link: #136872; --band: #E3E8E5; --code-bg: #DCE3DF;
  --on-accent: #EEF1EF; --cell: #B47A22;
  --t-bg: #0E1316; --t-bar: #151C20; --t-dot: #2A3439; --t-ink: #E8EDEA; --t-dim: #8E9A97; --t-key: #5CC4C9;
  --lift: 0 14px 34px rgba(14, 30, 34, 0.12);
  --texture: url("/assets/field-ink.svg");
  --sans: Inter, "Helvetica Neue", Arial, system-ui, sans-serif;
  --display: "Space Grotesk", Inter, "Helvetica Neue", Arial, system-ui, sans-serif;
  --mono: "Source Code Pro", ui-monospace, Menlo, Consolas, monospace;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --field: #0F1417; --ink: #E8EDEA; --muted: #9AA6A3; --rule: #263035;
    --accent: #5CC4C9; --link: #5CC4C9; --band: #161D21; --code-bg: #1C252A;
    --on-accent: #0F1417; --cell: #E0A44A;
    --t-bg: #0A0E10; --t-bar: #11181B;
    --lift: 0 14px 34px rgba(0, 0, 0, 0.45);
  }
}
/* The ink band: the polarized view of the slide, in both color schemes. */
.ink {
  --field: #0F1417; --ink: #E8EDEA; --muted: #9AA6A3; --rule: #263035;
  --accent: #5CC4C9; --link: #5CC4C9; --band: #161D21; --code-bg: #1C252A;
  --on-accent: #0F1417; --cell: #E0A44A;
  background: var(--field); color: var(--ink); color-scheme: dark;
}
@media (prefers-color-scheme: dark) {
  .ink { --field: #0A0E10; --band: #121A1E; --code-bg: #182126; --rule: #222B30; --texture: url("/assets/field-deep.svg"); }
}

* { box-sizing: border-box; }
html { background: var(--field); scroll-behavior: smooth; scroll-padding-top: 16px; }
body { margin: 0; background: var(--field); color: var(--ink);
  font: 17px/1.6 var(--sans); -webkit-text-size-adjust: 100%; overflow-x: hidden; }
a { color: var(--link); text-underline-offset: 3px; }
code, pre { font-family: var(--mono); font-size: 0.86em; }
pre code { font-size: inherit; }
.wrap { max-width: 1120px; margin: 0 auto; padding-left: 16px; padding-right: 16px; }
@media (min-width: 720px) { .wrap { padding-left: 32px; padding-right: 32px; } }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: 16px; top: -60px; z-index: 5; background: var(--ink); color: var(--field);
  padding: 10px 14px; border-radius: 8px; }
.skip:focus { top: 12px; }
[hidden] { display: none !important; }
:focus-visible { outline: 2px solid var(--link); outline-offset: 2px; }

/* Header and nav, inside the hero band */
.top { display: flex; align-items: center; justify-content: space-between; gap: 12px 16px;
  padding-top: 20px; padding-bottom: 12px; flex-wrap: wrap; }
.brand img { display: block; width: 176px; height: auto; }
nav { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 18px; }
nav a { color: var(--ink); text-decoration: none; font-size: 15px; }
nav a:hover { text-decoration: underline; }
nav a.nav-cta { color: var(--on-accent); background: var(--accent); padding: 7px 14px; border-radius: 999px; font-weight: 600; }
nav a.nav-cta:hover { text-decoration: none; filter: brightness(1.08); }

/* Buttons */
.button, .button-quiet { display: inline-flex; align-items: center; gap: 8px; font: 500 16px/1.2 var(--sans);
  padding: 12px 20px; border-radius: 999px; text-decoration: none; cursor: pointer; border: 1px solid transparent;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease; }
.button { background: var(--ink); color: var(--field); }
.button:hover { transform: translateY(-1px); box-shadow: var(--lift); }
.button-accent { background: var(--accent); color: var(--on-accent); font-weight: 600; }
.button-quiet { background: transparent; color: var(--ink); border-color: var(--rule); }
.button-quiet:hover { border-color: var(--ink); }
.button:focus-visible, .button-quiet:focus-visible { outline-offset: 3px; }

/* Hero */
.hero { position: relative; display: grid; gap: 28px 48px; align-items: center; padding-top: 36px; padding-bottom: 72px; }
@media (min-width: 900px) { .hero { grid-template-columns: 1fr 1.05fr; padding-top: 52px; padding-bottom: 96px; } }
.hero > * { min-width: 0; position: relative; z-index: 1; }
.hero-band { overflow: hidden; }
/* The compact-bone field sits only behind the session window's column, never behind text. */
@media (min-width: 900px) {
  .hero::before { content: ""; position: absolute; top: 0; bottom: 0; left: calc(50% + 24px); right: -240px;
    background: var(--texture) left center / auto 112% no-repeat; pointer-events: none; z-index: 0; }
}
.eyebrow { color: var(--muted); font-size: 14px; letter-spacing: 0.08em; text-transform: uppercase; margin: 0 0 14px; }
h1 { font-family: var(--display); font-weight: 500; font-size: clamp(36px, 5.4vw, 60px);
  line-height: 1.05; letter-spacing: -0.015em; margin: 0 0 22px; max-width: 17ch; text-wrap: balance; }
.lede { font-size: clamp(18px, 2.1vw, 20px); max-width: 42ch; margin: 0 0 28px; color: var(--ink); }
.lede strong { color: var(--accent); font-weight: 600; }
.actions { display: flex; gap: 22px; align-items: center; flex-wrap: wrap; margin: 0; }
.facts { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin: 28px 0 0; padding: 0; }
.facts li { font-size: 14px; color: var(--muted); padding: 5px 12px; border: 1px solid var(--rule); border-radius: 999px; }
.facts strong { color: var(--ink); font-weight: 600; }

/* The session window */
.term { min-width: 0; background: var(--t-bg); color: var(--t-ink); border: 1px solid var(--t-dot);
  border-radius: 14px; overflow: hidden; box-shadow: 0 24px 70px rgba(0, 0, 0, 0.45); }
.term-bar { display: flex; align-items: center; gap: 7px; padding: 11px 14px; background: var(--t-bar); }
.term-bar i { width: 11px; height: 11px; border-radius: 50%; background: var(--t-dot); }
.term-bar span { margin-left: 8px; font: 12px/1 var(--mono); color: var(--t-dim); }
.term-body { margin: 0; padding: 16px 18px 20px; font-size: 13.5px; line-height: 1.75; color: var(--t-ink); white-space: pre-wrap; }
.tl { display: inline-block; white-space: pre-wrap; overflow-wrap: anywhere; }
.tl .p { color: var(--t-key); font-weight: 600; margin-right: 6px; }
.tl.dim { color: var(--t-dim); }
.tl.key { color: var(--t-key); }
.js .tl { clip-path: inset(0 100% 0 0); }
.js .tl.on { animation: type .55s steps(28, end) forwards; }
.cursor { display: inline-block; width: 8px; height: 1.05em; margin-left: 4px; background: var(--t-key);
  vertical-align: text-bottom; animation: blink 1s steps(1) 6; }
@keyframes type { to { clip-path: inset(0 0 0 0); } }
@keyframes blink { 50% { opacity: 0; } }

/* Section frames and headings */
h2 { font-family: var(--display); font-weight: 500; margin: 0 0 12px; }
h2.kicker { font-size: 15px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }
h2.big { font-size: clamp(30px, 4vw, 44px); letter-spacing: -0.01em; line-height: 1.1; margin-bottom: 12px; text-wrap: balance; }
h3 { font-family: var(--display); font-weight: 600; }
.section-lede { max-width: 62ch; color: var(--muted); margin: 0 0 26px; font-size: 18px; }
.fine { font-size: 14.5px; color: var(--muted); margin: 12px 0 0; }
.how, .guide, .tiers, .closing { padding-top: 64px; padding-bottom: 64px; }
.guide, .tiers, .closing { border-top: 1px solid var(--rule); }

/* How it works: three messages, no boxes */
.cols { display: grid; gap: 28px 40px; margin-top: 18px; }
@media (min-width: 820px) { .cols { grid-template-columns: repeat(3, 1fr); } }
.cols article { border-top: 2px solid var(--ink); padding-top: 16px; }
.cols .num { font: 600 13px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--accent); margin: 0 0 12px; }
.cols h3 { font-size: clamp(22px, 2.4vw, 26px); line-height: 1.2; margin: 0 0 10px; }
.cols p { margin: 0; color: var(--muted); }

/* Command line with a copy button. The prompt glyph is drawn by CSS, so it is never copied. */
.cmd { position: relative; display: flex; align-items: flex-start; gap: 10px; background: var(--code-bg);
  border: 1px solid var(--rule); border-radius: 10px; padding: 10px 10px 10px 32px; margin: 10px 0 0; }
.cmd::before { content: attr(data-prompt); position: absolute; left: 13px; top: 10px; font: 600 14px/1.55 var(--mono); color: var(--link); user-select: none; }
.cmd code { flex: 1 1 auto; min-width: 0; font-size: 14px; line-height: 1.55; white-space: pre-wrap; overflow-wrap: anywhere; color: var(--ink); }
.copy { display: none; flex: none; font: 500 12.5px/1 var(--sans); color: var(--ink); background: var(--field);
  border: 1px solid var(--rule); border-radius: 7px; padding: 7px 10px; cursor: pointer; margin-left: auto;
  transition: background .2s ease, color .2s ease, border-color .2s ease; }
.js .copy { display: inline-flex; align-items: center; }
.copy:hover { border-color: var(--ink); }
.copy.done { background: var(--ink); color: var(--field); border-color: var(--ink); }
@media (max-width: 640px) { .cmd { flex-wrap: wrap; } .cmd code { font-size: 13.5px; } }

/* The guide */
.guide-head { display: grid; gap: 18px 40px; align-items: end; }
@media (min-width: 900px) { .guide-head { grid-template-columns: 1fr auto; } }
.route { border: 0; margin: 0 0 26px; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.route legend { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 8px; padding: 0; }
.route label { cursor: pointer; }
.route input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.route label span { display: block; padding: 10px 16px; border: 1px solid var(--rule); border-radius: 12px; background: var(--field); }
.route label b { display: block; font-weight: 600; font-size: 15px; }
.route label small { display: block; font-size: 13px; color: var(--muted); }
.route input:checked + span { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); background: var(--band); }
.route input:focus-visible + span { outline: 2px solid var(--link); outline-offset: 2px; }
html:not(.js) .route { display: none; }
.before { margin: 0 0 22px; border: 1px dashed var(--rule); border-radius: 12px; padding: 12px 18px; }
.before summary { cursor: pointer; font-weight: 600; }
.before ul { margin: 10px 0 4px; padding-left: 20px; color: var(--muted); font-size: 15.5px; }
.wizard { display: grid; gap: 20px 36px; background: var(--band); border: 1px solid var(--rule); border-radius: 16px; padding: 22px; position: relative; }
@media (min-width: 900px) { .wizard { padding: 28px; } .js .wizard { grid-template-columns: 260px 1fr; } }
.wizard > * { min-width: 0; }
.wiz-progress { grid-column: 1 / -1; height: 6px; background: var(--rule); border-radius: 999px; overflow: hidden; }
.wiz-bar { display: block; height: 100%; width: 0; background: var(--accent); border-radius: 999px; transition: width .4s ease; }
html:not(.js) .wiz-progress, html:not(.js) .wiz-nav, html:not(.js) .wiz-step .wiz-actions { display: none; }
.wiz-nav { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px; align-content: start; }
.wiz-nav button { width: 100%; display: flex; align-items: center; gap: 12px; text-align: left; font: 500 15px/1.3 var(--sans);
  color: var(--muted); background: transparent; border: 0; border-radius: 10px; padding: 9px 10px; cursor: pointer; }
.wiz-nav button i { flex: none; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center;
  font: 600 13px/1 var(--display); font-style: normal; border: 1.5px solid var(--rule); color: var(--muted); }
.wiz-nav button:hover { color: var(--ink); }
.wiz-nav button[aria-current="step"] { color: var(--ink); background: var(--field); }
.wiz-nav button[aria-current="step"] i { border-color: var(--accent); color: var(--accent); }
.wiz-nav button.is-done i { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
@media (max-width: 899px) {
  .wiz-nav { grid-template-columns: repeat(6, 1fr); gap: 6px; }
  .wiz-nav button { justify-content: center; padding: 6px 0; }
  .wiz-nav button span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
}
.wiz-step + .wiz-step { margin-top: 30px; padding-top: 26px; border-top: 1px solid var(--rule); }
.js .wiz-step + .wiz-step { margin-top: 0; padding-top: 0; border-top: 0; }
.wiz-count { font: 600 12.5px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--accent); margin: 2px 0 10px; }
.wiz-step h3, .wiz-end h3 { font-size: clamp(22px, 2.6vw, 28px); line-height: 1.2; margin: 0 0 10px; }
.wiz-step h3:focus, .wiz-end h3:focus { outline: none; }
:where(.wiz-step, .when) > p { margin: 0 0 6px; max-width: 64ch; }
.when + .when { margin-top: 22px; }
.route-label { font-size: 13px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase; color: var(--muted); }
.js .route-label { display: none; }
.wiz-actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0 0 !important; }
.checks { list-style: none; margin: 4px 0 8px; padding: 0; display: grid; gap: 6px; }
.checks li { position: relative; padding-left: 28px; }
.checks li::before { content: ""; position: absolute; left: 2px; top: 5px; width: 14px; height: 14px; border: 1.5px solid var(--muted); border-radius: 4px; }

/* Skills, in an ink band */
.skills { padding-top: 64px; padding-bottom: 64px; }
.toolbar { display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: center; margin-bottom: 10px; }
html:not(.js) .toolbar { display: none; }
.search { position: relative; flex: 1 1 320px; display: flex; align-items: center; }
.search svg { position: absolute; left: 13px; width: 18px; height: 18px; fill: none; stroke: var(--muted); stroke-width: 1.8; stroke-linecap: round; pointer-events: none; }
.search input { width: 100%; font: 16px/1.3 var(--sans); color: var(--ink); background: var(--band);
  border: 1px solid var(--rule); border-radius: 10px; padding: 11px 14px 11px 40px; -webkit-appearance: none; appearance: none; }
.search input::placeholder { color: var(--muted); opacity: 1; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { font: 500 14px/1 var(--sans); color: var(--ink); background: transparent; border: 1px solid var(--rule);
  border-radius: 999px; padding: 9px 14px; cursor: pointer; }
.chip span { color: var(--muted); margin-left: 4px; font-variant-numeric: tabular-nums; }
.chip[aria-pressed="true"] { background: var(--ink); color: var(--field); border-color: var(--ink); }
.chip[aria-pressed="true"] span { color: inherit; opacity: .75; }
.count { font-size: 14px; color: var(--muted); margin: 0 0 22px; }
.sgroup { margin-bottom: 30px; }
.sgroup h3 { font-size: 15px; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); font-weight: 500; margin: 0 0 12px; }
.slist { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
@media (min-width: 820px) { .slist { grid-template-columns: 1fr 1fr; } }
@media (min-width: 1100px) { .slist { grid-template-columns: 1fr 1fr 1fr; } }
.skill { background: var(--band); border: 1px solid var(--rule); border-radius: 12px; padding: 12px; transition: border-color .2s ease; }
.skill:hover { border-color: var(--muted); }
.skill .cmd { margin: 0; background: var(--field); }
.skill p { margin: 10px 4px 2px; font-size: 15.5px; }
.needs { display: block; margin-top: 4px; font-size: 13.5px; color: var(--muted); }
.empty { color: var(--muted); }
.linkish { font: inherit; color: var(--link); background: none; border: 0; padding: 0; text-decoration: underline; text-underline-offset: 3px; cursor: pointer; }

/* Tiers */
.tiers-grid { display: grid; gap: 24px 44px; align-items: center; }
@media (min-width: 860px) { .tiers-grid { grid-template-columns: 0.75fr 1.25fr; } }
.tiers-grid > * { min-width: 0; }
.rings { margin: 0 auto; width: 100%; max-width: 340px; }
.rings svg { display: block; width: 100%; height: auto; }
.rings circle { stroke: var(--ink); stroke-width: 2; }
.rings .r0 { fill: color-mix(in srgb, var(--accent) 7%, transparent); stroke-width: 3.2; }
.rings .r1 { fill: color-mix(in srgb, var(--accent) 13%, var(--field)); }
.rings .r2 { fill: color-mix(in srgb, var(--accent) 22%, var(--field)); }
.rings .canal { fill: var(--field); }
.rings text { font: 600 13px var(--display); fill: var(--ink); text-anchor: middle; letter-spacing: .04em; }
.tier-table { width: 100%; border-collapse: collapse; font-size: 15.5px; margin-bottom: 18px; }
.tier-table th, .tier-table td { text-align: left; vertical-align: top; padding: 12px 14px 12px 0; border-bottom: 1px solid var(--rule); }
.tier-table thead th { font-family: var(--display); font-weight: 600; font-size: 14px; color: var(--muted); }
.tier-table tbody th { font-family: var(--display); font-weight: 600; white-space: nowrap; }
.tier-table td:nth-child(2) { color: var(--muted); }
:where(.tiers) p { margin: 0 0 8px; max-width: 64ch; }
@media (max-width: 640px) {
  .tier-table thead { display: none; }
  .tier-table tbody tr { display: block; padding: 12px 0; border-bottom: 1px solid var(--rule); }
  .tier-table tbody th, .tier-table td { display: block; border: 0; padding: 2px 0; }
  .tier-table td::before { content: attr(data-l); display: block; font-size: 12px; color: var(--muted); }
}

/* Cite and the name */
.closing { display: grid; gap: 28px 48px; }
@media (min-width: 820px) { .closing { grid-template-columns: 1.3fr 1fr; } }
.closing p { margin: 0; max-width: 60ch; }
.closing p.fine { margin-top: 12px; }

.foot { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  color: var(--muted); font-size: 14px; padding-top: 28px; padding-bottom: 40px; border-top: 1px solid var(--rule); }
.foot p { margin: 0; }

/* Scroll reveal, only when the script runs */
.js .reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
.js .reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { transition: none; opacity: 1; transform: none; }
  .js .tl, .js .tl.on { animation: none; clip-path: none; }
  .cursor { animation: none; }
  .button:hover { transform: none; }
  .wiz-bar { transition: none; }
}
@media (forced-colors: active) {
  .chip[aria-pressed="true"], .route input:checked + span, .wiz-nav button[aria-current="step"] {
    forced-color-adjust: none; background: Highlight; color: HighlightText; border-color: Highlight; }
  .chip[aria-pressed="true"] span, .route input:checked + span small, .wiz-nav button[aria-current="step"] i { color: HighlightText; border-color: HighlightText; }
  .wiz-nav button.is-done i { forced-color-adjust: none; background: CanvasText; color: Canvas; border-color: CanvasText; }
  .wiz-progress { border: 1px solid CanvasText; }
  .wiz-bar { forced-color-adjust: none; background: CanvasText; }
}
@media print {
  .js .reveal { opacity: 1 !important; transform: none !important; }
  .js .tl { clip-path: none !important; }
  .copy, .toolbar, .cursor, .route, .wiz-nav, .wiz-progress, .wiz-actions, .skip { display: none !important; }
  .js .wiz-step, .js .wiz-step .when { display: block !important; }
  .js .route-label { display: block !important; }
  .wizard, .js .wizard { display: block; }
  .hero::before { display: none; }
  .ink { --field: #EEF1EF; --ink: #17191E; --muted: #4E5856; --rule: #CBD3CF; --band: #E3E8E5; --code-bg: #DCE3DF;
    --accent: #136872; --link: #136872; --on-accent: #EEF1EF; }
  .term { --t-bg: #EEF1EF; --t-bar: #E3E8E5; --t-dot: #CBD3CF; --t-ink: #17191E; --t-dim: #4E5856; --t-key: #136872; box-shadow: none; }
}