/* Diagnostic Intelligence · the world
   One accent (DI teal). Amber is reserved for "needs a person". */

@font-face { font-family: 'Cabinet Grotesk'; src: url('fonts/cabinet-grotesk-variable.woff2') format('woff2'); font-weight: 100 900; font-display: swap; }
@font-face { font-family: 'Figtree'; src: url('fonts/figtree-latin-wght-normal.woff2') format('woff2'); font-weight: 300 900; font-display: swap; }
@font-face { font-family: 'JetBrains Mono'; src: url('fonts/jetbrains-mono-latin-wght-normal.woff2') format('woff2'); font-weight: 100 800; font-display: swap; }

:root {
  color-scheme: light;
  --page: #f2f5f5;
  --surface: #ffffff;
  --sheet: #fffdf8;
  --ink: #17222c;
  --ink-2: #47535f;
  --ink-3: #5a6570;
  --rule: rgb(23 34 44 / 0.12);
  --rule-strong: rgb(23 34 44 / 0.2);
  --teal: #0b8a84;
  --teal-deep: #006a67;
  --teal-soft: #dcf1ee;
  --amber: #9a5b00;
  --amber-line: #e0a02e;
  --amber-soft: #fdf1da;
  --deep: #0e2a33;
  --display: 'Cabinet Grotesk', 'Figtree', system-ui, sans-serif;
  --sans: 'Figtree', system-ui, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, Consolas, monospace;
  --hindi: 'Figtree', 'Nirmala UI', 'Noto Sans Devanagari', sans-serif;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --nav-h: 68px;
  --gutter: clamp(20px, 4.5vw, 72px);
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 12px); }
body { margin: 0; background: var(--page); color: var(--ink); font: 400 1.0625rem/1.6 var(--sans); -webkit-font-smoothing: antialiased; overflow-x: clip; }
h1, h2, h3 { font-family: var(--display); font-weight: 800; letter-spacing: -0.03em; margin: 0; text-wrap: balance; }
p { margin: 0; text-wrap: pretty; }
a { color: inherit; }
button { font: inherit; }
:focus-visible { outline: 2.5px solid var(--teal-deep); outline-offset: 3px; border-radius: 4px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.skip { position: absolute; left: 12px; top: -60px; z-index: 50; padding: 10px 14px; background: var(--ink); color: #fff; border-radius: 8px; text-decoration: none; }
.skip:focus { top: 12px; }
.wrap { width: min(1180px, 100% - 2 * var(--gutter)); margin-inline: auto; }

/* ------------------------------------------------------------------ nav */
.nav { position: sticky; top: 0; z-index: 20; height: var(--nav-h); background: var(--page); border-bottom: 1px solid transparent; transition: border-color 0.3s var(--ease); }
.nav.is-scrolled { border-bottom-color: var(--rule); }
.nav-inner { height: 100%; padding-inline: var(--gutter); display: flex; align-items: center; gap: 32px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.brand-mark { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 9px; background: var(--teal-deep); color: #fff; font: 800 17px/1 var(--display); padding-bottom: 2px; }
.brand-name { font: 700 1rem/1 var(--display); letter-spacing: -0.01em; white-space: nowrap; }
.nav-links { display: flex; gap: 28px; margin-left: auto; }
.nav-links a, .link-quiet { font-size: 0.95rem; color: var(--ink-2); text-decoration: none; padding: 6px 0; }
.nav-links a:hover, .link-quiet:hover { color: var(--ink); }
.nav-actions { display: flex; align-items: center; gap: 20px; }

.btn { display: inline-flex; align-items: center; justify-content: center; white-space: nowrap; min-height: 48px; padding: 0 22px; border-radius: 999px; font: 600 1rem/1 var(--sans); text-decoration: none; border: 1px solid transparent; cursor: pointer; transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease), transform 0.15s var(--ease); }
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--teal-deep); color: #fff; }
.btn-primary:hover { background: #00514f; }
.btn-ghost { background: var(--surface); color: var(--ink); border-color: var(--rule-strong); }
.btn-ghost:hover { border-color: var(--ink); }
.btn-sm { min-height: 40px; padding: 0 18px; font-size: 0.95rem; }
.btn-lg { min-height: 56px; padding: 0 28px; font-size: 1.05rem; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }

/* ---------------------------------------------------------------- story
   The world is a sticky stage behind the whole story; the copy column runs
   over its left edge, where a paper fade keeps the text readable. */
.story { display: grid; grid-template-columns: 1fr; position: relative; }
.world { grid-area: 1 / 1; position: sticky; top: var(--nav-h); align-self: start; height: calc(100svh - var(--nav-h)); overflow: hidden; }
.world canvas { display: block; width: 100%; height: 100%; }
.world::after { content: ''; position: absolute; inset: 0; pointer-events: none; background: linear-gradient(90deg, var(--page) 0%, rgb(242 245 245 / 0.95) 33%, rgb(242 245 245 / 0.6) 42%, rgb(242 245 245 / 0) 53%); }
.world-status { position: absolute; left: 70%; top: 50%; transform: translate(-50%, -50%); z-index: 2; padding: 10px 16px; border-radius: 999px; background: var(--surface); color: var(--ink-2); font-size: 0.95rem; box-shadow: 0 12px 30px -18px rgb(14 42 51 / 0.45); }
.world-status:empty { display: none; }
.rail { position: absolute; top: 18px; left: 70%; transform: translateX(-50%); z-index: 3; display: flex; gap: 2px; padding: 4px; background: var(--surface); border: 1px solid var(--rule); border-radius: 999px; box-shadow: 0 8px 24px -16px rgb(14 42 51 / 0.4); }
.rail a { padding: 7px 13px; border-radius: 999px; font: 600 0.8rem/1 var(--sans); color: var(--ink-3); text-decoration: none; white-space: nowrap; transition: background-color 0.3s var(--ease), color 0.3s var(--ease); }
.rail a:hover { color: var(--ink); }
.rail a.is-on { background: var(--ink); color: #fff; }

.steps { grid-area: 1 / 1; position: relative; z-index: 2; width: min(31rem, 38vw); margin-left: var(--gutter); }
.step { min-height: calc(100svh - var(--nav-h)); display: flex; flex-direction: column; justify-content: center; padding-block: 12vh; }
.step h2 { font-size: clamp(2rem, 3vw, 3rem); line-height: 1.02; margin-bottom: 18px; }
.step > p { color: var(--ink-2); font-size: 1.1rem; }
.kicker, .step > .kicker { font: 600 0.95rem/1.2 var(--sans); color: var(--teal-deep); margin-bottom: 16px; }
.step-hero h1 { font-size: clamp(3.2rem, 6.4vw, 6.2rem); line-height: 0.92; letter-spacing: -0.045em; margin-bottom: 26px; }
.step-hero .hl { color: var(--teal-deep); }
.step-hero .lede { font-size: clamp(1.1rem, 1.35vw, 1.25rem); color: var(--ink-2); }

/* --------------------------------------------------------------- cards */
.card { margin-top: 28px; background: var(--surface); border-radius: 18px; padding: 18px 20px; box-shadow: 0 24px 48px -30px rgb(14 42 51 / 0.45), 0 0 0 1px var(--rule); max-width: 27rem; transform: translateY(12px); transition: transform 0.7s var(--ease), box-shadow 0.7s var(--ease); }
.step.is-active .card { transform: none; box-shadow: 0 30px 60px -30px rgb(14 42 51 / 0.5), 0 0 0 1px var(--rule); }
.card-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; padding-bottom: 10px; margin-bottom: 4px; border-bottom: 1px solid var(--rule); }
.card-head b { font: 700 1rem/1.2 var(--display); letter-spacing: -0.01em; }
.card-head small { font: 500 0.75rem/1.2 var(--mono); color: var(--ink-3); white-space: nowrap; }

.card-sheet { background: var(--sheet); border-radius: 6px; font-size: 0.85rem; transform: translateY(14px) rotate(-1.2deg); }
.step.is-active .card-sheet { transform: rotate(-1.2deg); }
.card-sheet .card-head { border-bottom: 1.5px solid var(--ink); }
.sheet-row { display: grid; grid-template-columns: 1fr 4.5rem 5.2rem; gap: 8px; align-items: center; padding: 6px 0; border-bottom: 1px dotted #d9d4c8; }
.sheet-row b { font: 600 0.82rem/1 var(--mono); }
.sheet-row small { font: 500 0.75rem/1 var(--mono); color: var(--ink-3); }
.sheet-row.is-review b { filter: blur(1.2px); }

.f-row { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 0 12px; padding: 5px 0; border-bottom: 1px solid var(--rule); }
.f-row:last-child { border-bottom: 0; }
.f-name { font-weight: 600; font-size: 0.88rem; }
.f-src { grid-column: 1; font: 500 0.72rem/1.3 var(--mono); color: var(--ink-3); }
.f-val { grid-row: 1; grid-column: 2; text-align: right; font: 600 0.92rem/1 var(--mono); }
.f-val small { font-size: 0.72rem; color: var(--ink-3); margin-left: 3px; font-weight: 500; }
.f-status { grid-column: 2; text-align: right; font-size: 0.72rem; font-weight: 600; color: var(--ink-3); }
.f-row.is-in .f-status { color: var(--teal-deep); }
.f-row.is-high .f-status { color: var(--ink); }
.f-row.is-review { background: linear-gradient(90deg, var(--amber-soft), transparent); margin-inline: -20px; padding-inline: 20px; }
.f-row.is-review .f-val, .f-row.is-review .f-status, .f-row.is-review .f-src { color: var(--amber); }

.card-chat { background: #eef2ef; }
.lang { display: inline-flex; padding: 4px; border-radius: 999px; background: var(--surface); border: 1px solid var(--rule); gap: 4px; margin-bottom: 12px; }
.lang-btn { min-height: 40px; padding: 0 16px; border: 0; border-radius: 999px; background: transparent; color: var(--ink-2); cursor: pointer; font-weight: 600; }
.lang-btn[aria-pressed="true"] { background: var(--ink); color: #fff; }
.lang-btn[lang="hi"] { font-family: var(--hindi); }
.chat { display: flex; flex-direction: column; gap: 8px; }
.bubble { max-width: 280px; padding: 9px 12px; border-radius: 16px; background: #fff; font: 400 14px/20px var(--hindi); color: var(--ink); box-shadow: 0 1px 1px rgb(0 0 0 / 0.06); overflow-wrap: break-word; }
.bubble.in { align-self: flex-start; border-top-left-radius: 4px; }
.bubble.out { align-self: flex-end; background: #d7f2e3; border-top-right-radius: 4px; }

.doc-row { display: grid; grid-template-columns: 1fr auto; gap: 2px 12px; padding: 9px 0; border-bottom: 1px solid var(--rule); }
.doc-row:last-of-type { border-bottom: 0; }
.doc-row b { font-weight: 600; font-size: 0.92rem; }
.doc-row .v { font: 600 0.92rem/1.2 var(--mono); text-align: right; }
.doc-row small { font: 500 0.72rem/1.3 var(--mono); color: var(--ink-3); }
.doc-row .src { justify-self: end; font: 600 0.72rem/1 var(--sans); color: var(--teal-deep); background: var(--teal-soft); border-radius: 999px; padding: 4px 8px; }
.doc-note { margin-top: 10px; font-size: 0.82rem; color: var(--ink-3); }

.pk-line { display: grid; grid-template-columns: 20px 1fr auto; gap: 10px; align-items: start; padding: 10px 0; border-bottom: 1px solid var(--rule); }
.pk-icon { width: 20px; height: 20px; border-radius: 50%; display: grid; place-items: center; font: 700 11px/1 var(--sans); color: #fff; background: var(--teal-deep); }
.pk-line.is-gap .pk-icon { background: var(--amber-line); color: #3b2500; }
.pk-line b { display: block; font-weight: 600; font-size: 0.92rem; }
.pk-line small { font: 500 0.72rem/1.3 var(--mono); color: var(--ink-3); }
.pk-line.is-gap small { color: var(--amber); }
.pk-amt { font: 600 0.92rem/1.3 var(--mono); }
.pk-math { display: flex; justify-content: space-between; font-size: 0.9rem; color: var(--ink-2); padding-top: 6px; }
.pk-math b { font: 600 0.92rem/1.3 var(--mono); color: var(--ink); }
.pk-total { margin-top: 6px; padding-top: 8px; border-top: 1.5px solid var(--ink); color: var(--ink); font-weight: 600; }
.pk-foot { display: flex; justify-content: space-between; align-items: center; margin-top: 14px; }
.pk-foot small { font: 500 0.72rem/1.3 var(--mono); color: var(--ink-3); }
.stamp { padding: 8px 12px; border: 2px solid var(--teal-deep); border-radius: 8px; color: var(--teal-deep); font: 700 0.75rem/1 var(--display); letter-spacing: 0.08em; text-transform: uppercase; transform: rotate(-6deg); }

/* ----------------------------------------------------------- principles */
.principles { position: relative; z-index: 4; background: var(--deep); color: #e8efef; padding-block: clamp(88px, 12vw, 160px); }
.pr-grid { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: 48px 72px; align-items: start; }
.principles h2 { font-size: clamp(2.4rem, 5vw, 4.5rem); line-height: 0.98; color: #fff; position: sticky; top: calc(var(--nav-h) + 32px); }
.pr-list { margin: 0; }
.pr-list > div { padding: 26px 0; border-top: 1px solid rgb(255 255 255 / 0.16); display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr); gap: 8px 32px; }
.pr-list dt { font: 700 1.25rem/1.2 var(--display); color: #fff; }
.pr-list dd { margin: 0; color: #b9c8c9; }
.pr-foot { grid-column: 2; font-size: 0.9rem; color: #92a6a8; padding-top: 24px; border-top: 1px solid rgb(255 255 255 / 0.16); }
.foot { position: relative; z-index: 4; background: var(--page); border-top: 1px solid var(--rule); padding-block: 32px; }
.foot-inner { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 16px; }
.foot p { font-size: 0.9rem; color: var(--ink-3); }

/* ---------------------------------------------------- no WebGL, no JS */
.no-js .world, .no-webgl .world { display: none; }
.no-js .steps, .no-webgl .steps { width: min(40rem, 100% - 2 * var(--gutter)); }
.no-js .card { transform: none; }

/* ----------------------------------------------------------- responsive */
@media (max-width: 1100px) {
  .nav-links { display: none; }
  .nav-actions { margin-left: auto; }
  .rail a { padding: 7px 10px; }
}
@media (max-width: 900px) {
  :root { --nav-h: 60px; }
  .story { grid-template-rows: auto auto; }
  .world { grid-area: 1 / 1; z-index: 3; height: 46svh; }
  .world::after { background: linear-gradient(180deg, rgb(242 245 245 / 0) 82%, var(--page) 100%); }
  .world-status { left: 50%; }
  .rail { display: none; }
  .steps { grid-area: 2 / 1; width: auto; margin: 0; padding-inline: var(--gutter); }
  .step { min-height: 78svh; justify-content: flex-start; padding-block: 5svh 12svh; }
  .step-hero { min-height: auto; padding-bottom: 14svh; }
  .step-hero h1 { font-size: clamp(3rem, 14vw, 4.4rem); }
  .step h2 { font-size: clamp(1.9rem, 8vw, 2.5rem); }
  .card { max-width: none; }
  .pr-grid { grid-template-columns: 1fr; }
  .principles h2 { position: static; }
  .pr-list > div { grid-template-columns: 1fr; }
  .pr-foot { grid-column: 1; }
}
@media (max-width: 480px) {
  .nav-actions .link-quiet { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .card { transition: none; }
}