@layer reset, tokens, base, layout, components, motion, utilities;

@layer reset {
  *,
  *::before,
  *::after { box-sizing: border-box; }
  * { margin: 0; }
  html { scroll-behavior: smooth; }
  body { min-height: 100vh; }
  img, svg, canvas, video { display: block; max-width: 100%; }
  button, input, textarea, select { font: inherit; }
  button { color: inherit; }
  a { color: inherit; }
}

@layer tokens {
  :root {
    color-scheme: dark;
    --ink: #0b0b0e;
    --ink-2: #121318;
    --ink-3: #1b1c23;
    --paper: #f4f1e8;
    --paper-2: #d9d5ca;
    --muted: #97979f;
    --line: #2c2d35;
    --acid: #d9ff43;
    --coral: #ff5c39;
    --cyan: #64dcf2;
    --violet: #a88bff;
    --pink: #ff8fd8;
    --green: #6cf0b2;
    --shadow: rgb(0 0 0 / .3);
    --font-sans: "Manrope", "Helvetica Neue", Arial, sans-serif;
    --font-mono: "DM Mono", "SFMono-Regular", Consolas, monospace;
    --fluid-0: clamp(.76rem, .71rem + .18vw, .88rem);
    --fluid-1: clamp(.95rem, .88rem + .3vw, 1.15rem);
    --fluid-2: clamp(1.2rem, 1.02rem + .7vw, 1.7rem);
    --fluid-3: clamp(1.8rem, 1.35rem + 1.9vw, 3.2rem);
    --fluid-4: clamp(3rem, 1.5rem + 6.5vw, 8.5rem);
    --page: min(100% - 2rem, 1440px);
  }

  [data-theme="paper"] {
    color-scheme: light;
    --ink: #f2efe6;
    --ink-2: #fffdf7;
    --ink-3: #e5e1d7;
    --paper: #141419;
    --paper-2: #34343c;
    --muted: #66666e;
    --line: #cbc7bd;
    --shadow: rgb(48 43 32 / .14);
  }
}

@layer base {
  html {
    background: var(--ink);
    scrollbar-color: var(--acid) var(--ink-2);
  }

  body {
    overflow-x: clip;
    background:
      radial-gradient(circle at 80% 8%, color-mix(in oklch, var(--violet) 10%, transparent), transparent 22rem),
      var(--ink);
    color: var(--paper);
    font: 500 var(--fluid-1)/1.65 var(--font-sans);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
  }

  ::selection {
    background: var(--acid);
    color: #0b0b0e;
  }

  ::highlight(search-hit) {
    background: color-mix(in oklch, var(--acid) 72%, transparent);
    color: #0b0b0e;
  }

  h1, h2, h3 {
    font-weight: 800;
    line-height: .96;
    letter-spacing: -.055em;
    text-wrap: balance;
  }

  p { text-wrap: pretty; }

  code, kbd {
    font-family: var(--font-mono);
    font-size: .86em;
  }

  button, a { -webkit-tap-highlight-color: transparent; }

  :focus-visible {
    outline: 3px solid var(--acid);
    outline-offset: 4px;
  }

  a { text-underline-offset: .22em; }
}

@layer layout {
  .section-shell {
    width: var(--page);
    margin-inline: auto;
    padding-block: clamp(6rem, 11vw, 11rem);
  }

  .section-index,
  .eyebrow {
    font-family: var(--font-mono);
    font-size: var(--fluid-0);
    font-weight: 500;
    letter-spacing: .11em;
    line-height: 1.4;
    text-transform: uppercase;
  }

  .section-index { color: var(--muted); }
  .eyebrow { color: var(--acid); }

  .section-heading {
    display: grid;
    grid-template-columns: minmax(14rem, .65fr) 1.35fr;
    gap: clamp(2rem, 8vw, 10rem);
    align-items: end;
    margin-bottom: clamp(3rem, 6vw, 6rem);
  }

  .section-heading > div { display: grid; gap: 1rem; }
  .section-heading h2 { max-width: 15ch; font-size: var(--fluid-3); }
}

@layer components {
  .skip-link {
    position: fixed;
    z-index: 1000;
    top: 1rem;
    left: 1rem;
    translate: 0 -200%;
    padding: .8rem 1rem;
    background: var(--acid);
    color: #0b0b0e;
    font-weight: 800;
    text-decoration: none;
  }
  .skip-link:focus { translate: 0; }

  .reading-line {
    position: fixed;
    z-index: 999;
    inset: 0 0 auto;
    height: 3px;
    scale: 0 1;
    transform-origin: left;
    background: linear-gradient(90deg, var(--coral), var(--acid), var(--cyan));
  }

  .site-header {
    position: absolute;
    z-index: 100;
    top: 0;
    left: 50%;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    width: var(--page);
    min-height: 5.5rem;
    translate: -50% 0;
    border-bottom: 1px solid rgb(244 241 232 / .15);
  }

  .wordmark {
    display: inline-flex;
    width: max-content;
    align-items: baseline;
    color: inherit;
    font-size: 1.15rem;
    font-weight: 800;
    letter-spacing: -.06em;
    text-decoration: none;
  }
  .wordmark i { color: var(--acid); font-style: normal; }

  .site-header nav { display: flex; gap: clamp(1rem, 3vw, 2.5rem); }
  .site-header nav a {
    color: var(--paper-2);
    font: 400 .72rem/1 var(--font-mono);
    letter-spacing: .08em;
    text-decoration: none;
    text-transform: uppercase;
  }
  .site-header nav a:hover { color: var(--acid); }

  .header-actions { display: flex; justify-content: flex-end; align-items: center; gap: .5rem; }

  .icon-button,
  .progress-pill {
    min-height: 2.6rem;
    border: 1px solid rgb(244 241 232 / .18);
    background: rgb(11 11 14 / .48);
    backdrop-filter: blur(12px);
    cursor: pointer;
  }

  .icon-button {
    display: inline-grid;
    grid-auto-flow: column;
    gap: .4rem;
    place-items: center;
    min-width: 2.6rem;
    border-radius: 50%;
  }
  .icon-button kbd { color: var(--muted); font-size: .58rem; }
  .theme-toggle { font-size: 1.1rem; }

  .progress-pill {
    display: inline-flex;
    align-items: center;
    gap: .45rem;
    padding-inline: .8rem;
    border-radius: 99px;
    font: .72rem/1 var(--font-mono);
  }
  .progress-dot { width: .45rem; height: .45rem; border-radius: 50%; background: var(--acid); box-shadow: 0 0 1rem var(--acid); }

  .progress-popover {
    position: fixed;
    inset: 5rem 1rem auto auto;
    max-width: 19rem;
    padding: 1.2rem;
    border: 1px solid var(--line);
    border-radius: 1rem;
    background: color-mix(in oklch, var(--ink-2) 90%, transparent);
    color: var(--paper);
    box-shadow: 0 1.4rem 4rem var(--shadow);
    backdrop-filter: blur(20px);
  }
  .progress-popover::backdrop { background: transparent; }
  .progress-popover strong { display: block; margin-block: .4rem .8rem; font-size: 1.2rem; }
  .progress-popover p:last-of-type { margin-top: .75rem; color: var(--muted); font-size: .78rem; line-height: 1.5; }
  .progress-popover:popover-open { animation: pop-in .25s ease-out; }
  .progress-popover:open { border-color: color-mix(in oklch, var(--acid) 38%, var(--line)); }

  .meter { overflow: hidden; height: .35rem; border-radius: 1rem; background: var(--line); }
  .meter span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--coral), var(--acid)); transition: width .5s ease; }

  .button {
    display: inline-flex;
    min-height: 3.3rem;
    align-items: center;
    justify-content: center;
    gap: .7rem;
    padding: .85rem 1.2rem;
    border: 1px solid transparent;
    border-radius: 999px;
    font-size: .82rem;
    font-weight: 800;
    letter-spacing: -.015em;
    text-decoration: none;
    cursor: pointer;
    transition: transform .2s ease, background .2s ease, color .2s ease;
  }
  .button:hover { transform: translateY(-2px); }
  .button-primary { background: var(--acid); color: #0b0b0e; }
  .button-primary:hover { background: color-mix(in oklch, var(--acid) 86%, white); }
  .button-ghost { border-color: rgb(244 241 232 / .25); background: transparent; color: var(--paper); }
  .button-ghost:hover { border-color: var(--paper); }
  .text-button { border: 0; padding: 0; background: none; color: var(--paper); font: 500 .74rem/1 var(--font-mono); text-decoration: underline; text-underline-offset: .25em; cursor: pointer; }

  .hero {
    position: relative;
    isolation: isolate;
    min-height: max(760px, 100svh);
    overflow: hidden;
    padding: clamp(8rem, 16vh, 11rem) max(1rem, calc((100vw - 1440px) / 2)) 3rem;
    background:
      linear-gradient(90deg, transparent 49.9%, rgb(255 255 255 / .06) 50%, transparent 50.1%),
      linear-gradient(rgb(255 255 255 / .04) 1px, transparent 1px),
      linear-gradient(90deg, rgb(255 255 255 / .04) 1px, transparent 1px),
      #0b0b0e;
    background-size: 100% 100%, 64px 64px, 64px 64px, auto;
    color: #f4f1e8;
  }
  .hero::after {
    position: absolute;
    z-index: -1;
    inset: auto -10vw -25vw auto;
    width: 60vw;
    aspect-ratio: 1;
    border-radius: 50%;
    background: radial-gradient(circle, rgb(255 92 57 / .18), transparent 65%);
    content: "";
    filter: blur(4rem);
  }
  .hero-noise {
    position: absolute;
    z-index: -1;
    inset: 0;
    opacity: .18;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.18'/%3E%3C/svg%3E");
    pointer-events: none;
    mix-blend-mode: soft-light;
  }
  .hero-orbit {
    position: absolute;
    z-index: -1;
    border: 1px solid rgb(217 255 67 / .2);
    border-radius: 50%;
    pointer-events: none;
  }
  .orbit-one { top: 14%; right: 4%; width: min(38vw, 34rem); aspect-ratio: 1; }
  .orbit-two { top: 21%; right: 11%; width: min(24vw, 22rem); aspect-ratio: 1; border-color: rgb(100 220 242 / .18); }
  .orbit-one::before,
  .orbit-two::before {
    position: absolute;
    top: 50%;
    left: -5px;
    width: 9px;
    aspect-ratio: 1;
    border-radius: 50%;
    background: var(--acid);
    box-shadow: 0 0 1.2rem var(--acid);
    content: "";
  }
  .hero-kicker {
    display: flex;
    width: fit-content;
    align-items: center;
    gap: .75rem;
    margin-left: 7vw;
    font: .68rem/1 var(--font-mono);
    letter-spacing: .12em;
    text-transform: uppercase;
  }
  .hero-kicker span + span { padding-left: .75rem; border-left: 1px solid rgb(244 241 232 / .3); }
  .status-light { width: .5rem; aspect-ratio: 1; border-radius: 50%; background: var(--acid); box-shadow: 0 0 1rem var(--acid); }
  .hero-title { margin-top: clamp(3rem, 9vh, 6rem); color: #f4f1e8; font-size: var(--fluid-4); line-height: .78; letter-spacing: -.085em; }
  .hero-title .line { display: block; }
  .hero-title .line-two { margin-left: 7vw; }
  .hero-title em {
    color: transparent;
    font-style: normal;
    -webkit-text-stroke: max(1px, .015em) var(--acid);
    text-shadow: 0 0 2.5rem rgb(217 255 67 / .12);
  }
  .hero-footer {
    display: grid;
    grid-template-columns: minmax(16rem, 31rem) auto;
    gap: 2rem;
    align-items: end;
    margin: clamp(3rem, 7vh, 5rem) 7vw 0;
  }
  .hero-footer p { color: #b5b3ad; font-size: var(--fluid-1); }
  .hero-cta { display: flex; flex-wrap: wrap; gap: .7rem; }
  .hero-specimen {
    width: min(42rem, calc(100% - 14vw));
    margin: clamp(4rem, 8vh, 6rem) 0 0 auto;
    border: 1px solid rgb(244 241 232 / .18);
    background: rgb(15 16 20 / .72);
    box-shadow: 0 2rem 7rem rgb(0 0 0 / .32);
    backdrop-filter: blur(18px);
  }
  .specimen-head { display: flex; justify-content: space-between; padding: .7rem 1rem; border-bottom: 1px solid rgb(244 241 232 / .14); color: #8f8f94; font: .6rem/1 var(--font-mono); letter-spacing: .12em; }
  .signal-bars { display: flex; align-items: end; gap: 2px; }
  .signal-bars i { width: 2px; background: var(--acid); }
  .signal-bars i:nth-child(1) { height: 4px; } .signal-bars i:nth-child(2) { height: 7px; } .signal-bars i:nth-child(3) { height: 10px; }
  .capability-grid { display: grid; grid-template-columns: 1fr 1fr; }
  .capability-grid div { display: flex; justify-content: space-between; gap: 1rem; padding: .8rem 1rem; border-right: 1px solid rgb(244 241 232 / .1); border-bottom: 1px solid rgb(244 241 232 / .1); font: .66rem/1.4 var(--font-mono); }
  .capability-grid span { color: #a8a7a2; }
  .capability-grid strong { color: var(--acid); font-weight: 400; }
  .capability-grid strong[data-supported="false"] { color: var(--coral); }
  .scroll-cue { position: absolute; bottom: 2.4rem; left: max(1rem, calc((100vw - 1440px) / 2)); display: flex; align-items: center; gap: .8rem; color: #84848a; font: .62rem/1 var(--font-mono); letter-spacing: .1em; text-decoration: none; text-transform: uppercase; writing-mode: vertical-rl; }
  .scroll-cue i { display: block; width: 1px; height: 3rem; background: linear-gradient(var(--acid), transparent); }

  .manifesto {
    display: grid;
    grid-template-columns: .38fr 1.35fr;
    gap: clamp(2rem, 8vw, 9rem);
  }
  .manifesto-copy h2 { max-width: 18ch; margin-top: 1.3rem; font-size: clamp(2.2rem, 4.4vw, 5.5rem); }
  .manifesto-copy h2 span { color: var(--muted); }
  .manifesto-detail { max-width: 46rem; margin-top: 2rem; color: var(--paper-2); }
  .method-loop { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(4, 1fr); margin-top: clamp(3rem, 8vw, 7rem); padding: 0; border-top: 1px solid var(--line); list-style: none; }
  .method-loop li { position: relative; min-height: 15rem; padding: 1.2rem; border-right: 1px solid var(--line); }
  .method-loop li:last-child { border-right: 0; }
  .method-loop b { color: var(--muted); font: 400 .65rem/1 var(--font-mono); }
  .method-loop span { display: block; margin-top: clamp(3rem, 6vw, 5rem); font-size: var(--fluid-2); font-weight: 800; letter-spacing: -.04em; }
  .method-loop small { display: block; max-width: 14rem; margin-top: .7rem; color: var(--muted); font-size: .8rem; }
  .method-loop li::after { position: absolute; top: -5px; left: -1px; width: 9px; aspect-ratio: 1; border-radius: 50%; background: var(--line); content: ""; transition: background .25s ease, box-shadow .25s ease; }
  .method-loop li:hover::after { background: var(--acid); box-shadow: 0 0 1rem var(--acid); }

  .paths { border-top: 1px solid var(--line); }
  .path-grid { display: grid; grid-template-columns: repeat(12, 1fr); gap: 1rem; }
  .path-card {
    --path-accent: var(--acid);
    container-type: inline-size;
    position: relative;
    display: flex;
    grid-column: span 4;
    min-height: 35rem;
    overflow: hidden;
    flex-direction: column;
    padding: clamp(1.3rem, 3cqw, 2rem);
    border: 1px solid var(--line);
    background: var(--ink-2);
    transition: border-color .25s ease, transform .3s ease, box-shadow .3s ease;
  }
  .path-card:nth-child(1),
  .path-card:nth-child(5) { grid-column: span 7; }
  .path-card:nth-child(2),
  .path-card:nth-child(4) { grid-column: span 5; }
  .path-card:hover { z-index: 2; transform: translateY(-5px); border-color: color-mix(in oklch, var(--path-accent) 55%, var(--line)); box-shadow: 0 1.5rem 5rem var(--shadow); }
  .path-card::after { position: absolute; right: -20%; bottom: -35%; width: 75%; aspect-ratio: 1; border: 1px solid color-mix(in oklch, var(--path-accent) 35%, transparent); border-radius: 50%; content: ""; box-shadow: 0 0 6rem color-mix(in oklch, var(--path-accent) 9%, transparent); }
  .path-number { color: var(--muted); font: .7rem/1 var(--font-mono); }
  .path-icon { position: absolute; top: 1.2rem; right: 1.2rem; display: grid; width: 3.5rem; aspect-ratio: 1; place-items: center; border: 1px solid color-mix(in oklch, var(--path-accent) 60%, var(--line)); border-radius: 50%; color: var(--path-accent); font: 500 1.2rem/1 var(--font-mono); }
  .path-meta { display: flex; flex-wrap: wrap; gap: .45rem; margin-top: auto; font: .62rem/1 var(--font-mono); text-transform: uppercase; }
  .path-meta span { padding: .35rem .5rem; border: 1px solid var(--line); }
  .path-card h3 { max-width: 9ch; margin-top: 1.4rem; font-size: clamp(2.1rem, 7cqw, 4.4rem); }
  .path-card > p:not(.path-meta) { max-width: 35rem; margin-top: 1rem; color: var(--muted); font-size: .88rem; }
  .tag-list { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 1.2rem; padding: 0; list-style: none; }
  .tag-list li { color: var(--path-accent); font: .64rem/1 var(--font-mono); text-transform: uppercase; }
  .tag-list li + li::before { margin-right: .5rem; color: var(--muted); content: "/"; }
  .path-open { z-index: 1; display: flex; justify-content: space-between; margin-top: 2rem; padding: 1rem 0 0; border: 0; border-top: 1px solid var(--line); background: none; font-size: .78rem; font-weight: 800; cursor: pointer; }
  .path-open span { color: var(--path-accent); font-size: 1.2rem; }
  .path-platform { --path-accent: var(--acid); }
  .path-ux { --path-accent: var(--coral); }
  .path-a11y { --path-accent: var(--cyan); }
  .path-search { --path-accent: var(--violet); }
  .path-ai { --path-accent: var(--pink); }

  .now { width: 100%; padding-inline: max(1rem, calc((100vw - 1440px) / 2)); background: var(--paper); color: var(--ink); }
  .now-header { display: grid; grid-template-columns: .55fr 1fr .8fr; gap: clamp(2rem, 6vw, 7rem); align-items: end; width: 100%; max-width: 1440px; margin-inline: auto; }
  .now-header > div { display: grid; gap: 1rem; }
  .now .section-index { color: color-mix(in oklch, var(--ink) 50%, transparent); }
  .now .eyebrow { color: var(--coral); }
  .now-header h2 { font-size: var(--fluid-3); }
  .now-header > p { font-size: .88rem; }
  .feature-ticker { overflow: hidden; width: 100vw; margin: clamp(4rem, 8vw, 7rem) 0 0 calc(50% - 50vw); border-block: 1px solid color-mix(in oklch, var(--ink) 23%, transparent); }
  .feature-ticker div { display: flex; width: max-content; gap: 1.5rem; align-items: center; padding-block: .75rem; animation: ticker 28s linear infinite; font: 500 .7rem/1 var(--font-mono); }
  .feature-ticker i { color: var(--coral); font-style: normal; }
  .feature-list { max-width: 1440px; margin-inline: auto; }
  .feature-row { display: grid; grid-template-columns: .35fr .9fr 1.25fr auto; gap: 2rem; align-items: center; padding-block: 2rem; border-bottom: 1px solid color-mix(in oklch, var(--ink) 22%, transparent); }
  .feature-code { color: color-mix(in oklch, var(--ink) 55%, transparent); font: .62rem/1 var(--font-mono); }
  .feature-row h3 { font-size: clamp(1.3rem, 2.2vw, 2.4rem); line-height: 1; }
  .feature-row p { max-width: 45rem; color: color-mix(in oklch, var(--ink) 68%, transparent); font-size: .82rem; line-height: 1.6; }
  .baseline-badge { justify-self: end; padding: .45rem .65rem; border: 1px solid color-mix(in oklch, var(--ink) 32%, transparent); border-radius: 99px; font: .58rem/1 var(--font-mono); white-space: nowrap; }

  .lab { display: grid; grid-template-columns: .38fr 1.62fr; gap: clamp(2rem, 6vw, 7rem); }
  .lab-intro { align-self: start; position: sticky; top: 2rem; }
  .lab-intro .eyebrow { margin-top: 2rem; }
  .lab-intro h2 { max-width: 9ch; margin-top: 1.2rem; font-size: var(--fluid-3); }
  .lab-intro > p:not(.eyebrow, .section-index) { margin-top: 1.5rem; color: var(--muted); font-size: .88rem; }
  .lab-principles { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 2rem; }
  .lab-principles span { padding: .4rem .6rem; border: 1px solid var(--line); border-radius: 99px; color: var(--paper-2); font: .58rem/1 var(--font-mono); text-transform: uppercase; }
  .playground { overflow: hidden; border: 1px solid var(--line); border-radius: 1rem; background: #101116; box-shadow: 0 2rem 8rem var(--shadow); color: #f4f1e8; }
  .playground-bar { display: grid; grid-template-columns: 1fr auto 1fr; min-height: 3rem; align-items: center; padding-inline: 1rem; border-bottom: 1px solid #2c2d35; background: #17181e; }
  .traffic-lights { display: flex; gap: .38rem; }
  .traffic-lights i { width: .6rem; aspect-ratio: 1; border-radius: 50%; background: #444650; }
  .traffic-lights i:nth-child(1) { background: var(--coral); } .traffic-lights i:nth-child(2) { background: #ffc857; } .traffic-lights i:nth-child(3) { background: var(--green); }
  .editor-tabs { align-self: stretch; display: flex; }
  .editor-tabs button { padding-inline: 1rem; border: 0; border-bottom: 2px solid transparent; background: none; color: #7f8089; font: .62rem/1 var(--font-mono); cursor: pointer; }
  .editor-tabs button[aria-selected="true"] { border-color: var(--acid); color: #f4f1e8; }
  .preview-sizes { justify-self: end; }
  .preview-sizes button { border: 0; background: none; color: #777984; cursor: pointer; }
  .preview-sizes button[aria-pressed="true"] { color: var(--acid); }
  .playground-stage { display: grid; grid-template-columns: 1fr 1fr; min-height: 38rem; }
  .editor-pane { display: flex; min-width: 0; flex-direction: column; border-right: 1px solid #2c2d35; }
  .code-editor { display: none; width: 100%; min-height: 33rem; flex: 1; resize: none; border: 0; outline: 0; padding: 1.2rem; background: #101116; color: #d8d7d3; font: 400 .74rem/1.65 var(--font-mono); tab-size: 2; caret-color: var(--acid); }
  .code-editor.is-active { display: block; }
  .editor-actions { display: flex; min-height: 4.2rem; align-items: center; gap: 1rem; padding: .7rem 1rem; border-top: 1px solid #2c2d35; }
  .editor-actions .button { min-height: 2.5rem; padding: .55rem 1rem; font-size: .7rem; }
  .run-status { margin-left: auto; color: #767883; font: .6rem/1 var(--font-mono); }
  .preview-pane { min-width: 0; padding: 1rem; background: #1a1b21; transition: padding .3s ease; }
  .preview-label { display: flex; justify-content: space-between; margin-bottom: .7rem; color: #777984; font: .58rem/1 var(--font-mono); text-transform: uppercase; }
  .lab-frame { width: 100%; height: calc(100% - 1.3rem); min-height: 34rem; border: 1px solid #32343e; border-radius: .6rem; background: #111218; transition: width .3s ease; }
  .playground[data-size="narrow"] .lab-frame { width: min(100%, 23rem); margin-inline: auto; }

  .proof { border-top: 1px solid var(--line); }
  .proof-head { display: grid; grid-template-columns: 1.4fr .6fr; gap: 3rem; align-items: end; margin-top: 3rem; }
  .proof-head h2 { font-size: var(--fluid-3); }
  .proof-head h2 span { color: var(--muted); }
  .proof-head p { max-width: 30rem; color: var(--muted); font-size: .9rem; }
  .proof-strip { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 5rem; border: 1px solid var(--line); }
  .proof-strip article { min-height: 19rem; padding: 1.3rem; border-right: 1px solid var(--line); }
  .proof-strip article:last-child { border-right: 0; }
  .proof-strip span { color: var(--acid); font: .65rem/1 var(--font-mono); }
  .proof-strip h3 { margin-top: 6rem; font-size: 1.35rem; line-height: 1.05; }
  .proof-strip p { margin-top: 1rem; color: var(--muted); font-size: .76rem; line-height: 1.6; }

  .field-notes { border-top: 1px solid var(--line); }
  .notes-heading { display: grid; grid-template-columns: .65fr 1.35fr; gap: 4rem; align-items: end; margin-bottom: 4rem; }
  .notes-heading > div { display: grid; gap: 1rem; }
  .notes-heading h2 { font-size: var(--fluid-3); }
  .notes-list { border-top: 1px solid var(--line); }
  .notes-list a { display: grid; grid-template-columns: .35fr 1fr 1fr auto; gap: 2rem; align-items: center; min-height: 7rem; border-bottom: 1px solid var(--line); text-decoration: none; transition: padding .2s ease, background .2s ease; }
  .notes-list a:hover { padding-inline: 1rem; background: var(--ink-2); }
  .notes-list a > span { color: var(--acid); font: .62rem/1 var(--font-mono); text-transform: uppercase; }
  .notes-list h3 { font-size: 1.15rem; line-height: 1.2; letter-spacing: -.03em; }
  .notes-list p { color: var(--muted); font-size: .78rem; }
  .notes-list i { color: var(--acid); font-style: normal; }

  .closing { position: relative; isolation: isolate; display: grid; min-height: min(80rem, 100svh); overflow: hidden; place-content: center; padding: 4rem 1rem; background: #0b0b0e; color: #f4f1e8; text-align: center; }
  .closing::before { position: absolute; z-index: -1; inset: 10% 15%; border-radius: 50%; background: radial-gradient(ellipse, rgb(217 255 67 / .12), transparent 65%); content: ""; filter: blur(2rem); }
  .closing-grid { position: absolute; z-index: -2; inset: -20%; background-image: linear-gradient(rgb(217 255 67 / .08) 1px, transparent 1px), linear-gradient(90deg, rgb(217 255 67 / .08) 1px, transparent 1px); background-size: 5rem 5rem; transform: perspective(500px) rotateX(55deg) scale(1.5); mask-image: radial-gradient(circle, black 0 28%, transparent 70%); }
  .closing h2 { margin-block: 2rem 3rem; font-size: clamp(3rem, 9vw, 9rem); line-height: .82; }
  .closing h2 span { color: transparent; -webkit-text-stroke: 1px var(--acid); }
  .closing .button { justify-self: center; }

  .site-footer { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 2rem; align-items: end; width: var(--page); min-height: 13rem; margin-inline: auto; padding-block: 3rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .72rem; }
  .site-footer p { text-align: center; }
  .site-footer p a { color: var(--paper); }
  .site-footer > div { display: flex; justify-content: flex-end; gap: 1.5rem; }

  dialog {
    max-width: none;
    max-height: none;
    border: 0;
    padding: 0;
    background: transparent;
    color: inherit;
  }
  dialog::backdrop { background: rgb(3 3 5 / .8); backdrop-filter: blur(12px); }
  dialog[open] { animation: dialog-in .35s cubic-bezier(.2,.8,.2,1); }
  dialog:open { outline: 1px solid color-mix(in oklch, var(--acid) 20%, transparent); }
  @starting-style { dialog[open] { opacity: 0; transform: translateY(1rem) scale(.985); } }

  .path-dialog { width: min(76rem, calc(100% - 2rem)); margin: auto; }
  .dialog-shell { position: relative; display: grid; grid-template-columns: .72fr 1.28fr; max-height: min(52rem, calc(100svh - 2rem)); overflow: auto; border: 1px solid #34353e; border-radius: 1.2rem; background: #111218; color: #f4f1e8; box-shadow: 0 3rem 10rem rgb(0 0 0 / .6); }
  .dialog-close { position: absolute; z-index: 2; top: 1rem; right: 1rem; display: grid; width: 2.7rem; aspect-ratio: 1; place-items: center; border: 1px solid #3a3c46; border-radius: 50%; background: #17181e; font-size: 1.4rem; cursor: pointer; }
  .dialog-sidebar { --dialog-accent: var(--acid); display: flex; min-height: 42rem; flex-direction: column; padding: 2rem; border-right: 1px solid #2d2f38; background: linear-gradient(160deg, color-mix(in oklch, var(--dialog-accent) 12%, #111218), #111218 60%); }
  .dialog-symbol { display: grid; width: 6rem; aspect-ratio: 1; margin-block: 4rem 2rem; place-items: center; border: 1px solid var(--dialog-accent); border-radius: 50%; color: var(--dialog-accent); font: 500 2rem/1 var(--font-mono); }
  .dialog-label { color: var(--dialog-accent); font: .7rem/1 var(--font-mono); text-transform: uppercase; }
  .dialog-progress { display: grid; grid-template-columns: 1fr auto; gap: .6rem; margin-top: auto; font: .7rem/1 var(--font-mono); }
  .dialog-progress .meter { grid-column: 1 / -1; }
  .dialog-description { margin-top: 1.4rem; color: #91929c; font-size: .8rem; line-height: 1.6; }
  .dialog-content { padding: clamp(2rem, 5vw, 4rem); }
  .dialog-overline { color: #8a8b94; font: .68rem/1 var(--font-mono); text-transform: uppercase; }
  .dialog-content h2 { max-width: 10ch; margin-top: 1rem; font-size: clamp(2.7rem, 5vw, 5.5rem); }
  .dialog-outcome { max-width: 42rem; margin-top: 1.3rem; color: #a7a7af; font-size: .9rem; }
  .module-list { margin-top: 3rem; padding: 0; border-top: 1px solid #30313a; list-style: none; }
  .module-item { display: grid; grid-template-columns: auto 1fr auto; gap: 1rem; align-items: start; padding-block: 1.2rem; border-bottom: 1px solid #30313a; }
  .module-status { display: grid; width: 2rem; aspect-ratio: 1; place-items: center; border: 1px solid #4b4c56; border-radius: 50%; color: #858690; font: .58rem/1 var(--font-mono); }
  .module-status.is-complete { border-color: var(--acid); background: var(--acid); color: #101116; }
  .module-copy strong { display: block; font-size: .92rem; }
  .module-copy p { margin-top: .35rem; color: #858690; font-size: .72rem; line-height: 1.5; }
  .start-lesson { margin-top: .75rem; border: 0; padding: 0; background: none; color: var(--acid); font: 500 .65rem/1 var(--font-mono); cursor: pointer; text-decoration: underline; text-underline-offset: .25em; }
  .module-time { color: #686a75; font: .6rem/1 var(--font-mono); }
  .studio-brief { grid-column: 2 / -1; margin-top: .2rem; }
  .studio-brief summary { width: fit-content; color: var(--acid); font: .62rem/1 var(--font-mono); cursor: pointer; }
  .studio-brief[open] summary { margin-bottom: .8rem; }
  .studio-brief:open summary { text-decoration: underline; text-underline-offset: .25em; }
  .studio-brief p { max-width: 42rem; padding-left: 1rem; border-left: 1px solid #3b3d47; color: #92939d; font-size: .7rem; line-height: 1.55; }
  .studio-brief p + p { margin-top: .45rem; }
  .studio-brief strong { color: #f4f1e8; font-weight: 700; }

  .lesson-dialog {
    --lesson-accent: var(--acid);
    width: 100%;
    height: 100%;
    margin: 0;
    background: #0d0e13;
    color: #f4f1e8;
  }
  .lesson-dialog::backdrop { background: #0d0e13; }
  .lesson-shell { height: 100%; overflow: hidden; }
  .lesson-header {
    position: relative;
    z-index: 3;
    display: grid;
    grid-template-columns: 1fr minmax(12rem, 24rem) 1fr;
    min-height: 4.5rem;
    align-items: center;
    padding-inline: clamp(1rem, 3vw, 2.5rem);
    border-bottom: 1px solid #2d2f38;
    background: rgb(13 14 19 / .92);
    backdrop-filter: blur(18px);
  }
  .lesson-back,
  .lesson-close {
    border: 0;
    background: none;
    color: #b9bac2;
    cursor: pointer;
  }
  .lesson-back { justify-self: start; font: 500 .68rem/1 var(--font-mono); }
  .lesson-back span { margin-right: .5rem; color: var(--lesson-accent); }
  .lesson-close { justify-self: end; font-size: 1.6rem; }
  .lesson-header-progress { display: grid; grid-template-columns: auto 1fr; gap: .8rem; align-items: center; }
  .lesson-header-progress > span { color: #898b95; font: .58rem/1 var(--font-mono); text-transform: uppercase; }
  .lesson-header-progress .meter span { background: var(--lesson-accent); }
  .lesson-layout { display: grid; grid-template-columns: minmax(15rem, 20rem) 1fr; height: calc(100% - 4.5rem); }
  .lesson-rail { overflow-y: auto; padding: 2rem 1rem; border-right: 1px solid #2d2f38; background: #111218; }
  .lesson-rail > .eyebrow { padding-inline: .7rem; color: var(--lesson-accent); }
  .lesson-rail-list { display: grid; gap: .35rem; margin-top: 2rem; padding: 0; list-style: none; }
  .lesson-rail-list button {
    display: grid;
    grid-template-columns: 2rem 1fr;
    gap: .7rem;
    align-items: start;
    width: 100%;
    padding: .8rem .7rem;
    border: 1px solid transparent;
    border-radius: .65rem;
    background: none;
    color: #858791;
    text-align: left;
    cursor: pointer;
  }
  .lesson-rail-list button:hover { background: #191a21; color: #f4f1e8; }
  .lesson-rail-list button.is-active { border-color: color-mix(in oklch, var(--lesson-accent) 42%, #2d2f38); background: color-mix(in oklch, var(--lesson-accent) 8%, #15161c); color: #f4f1e8; }
  .lesson-rail-list span { display: grid; width: 1.6rem; aspect-ratio: 1; place-items: center; border: 1px solid #454750; border-radius: 50%; color: var(--lesson-accent); font: .52rem/1 var(--font-mono); }
  .lesson-rail-list strong { padding-top: .18rem; font-size: .68rem; line-height: 1.35; }
  .lesson-reader { overflow-y: auto; scroll-behavior: smooth; }
  .lesson-reader > * { width: min(100% - 2rem, 52rem); margin-inline: auto; }
  .lesson-hero { padding-block: clamp(4rem, 8vw, 8rem) clamp(3rem, 6vw, 5rem); border-bottom: 1px solid #30313a; }
  .lesson-kicker,
  .lesson-section-label { color: var(--lesson-accent); font: 500 .62rem/1.3 var(--font-mono); letter-spacing: .09em; text-transform: uppercase; }
  .lesson-hero h1 { max-width: 12ch; margin-top: 1rem; font-size: clamp(3rem, 7vw, 6.6rem); }
  .lesson-dek { max-width: 44rem; margin-top: 1.5rem; color: #a5a6af; font-size: clamp(.95rem, 1.4vw, 1.15rem); }
  .lesson-meta { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 3rem; border-block: 1px solid #30313a; }
  .lesson-meta div { padding: 1rem; border-right: 1px solid #30313a; }
  .lesson-meta div:last-child { border-right: 0; }
  .lesson-meta dt { color: #6f717c; font: .55rem/1 var(--font-mono); text-transform: uppercase; }
  .lesson-meta dd { margin: .45rem 0 0; font-size: .75rem; }
  .lesson-objectives,
  .lesson-chapter,
  .lesson-practice,
  .lesson-notes,
  .knowledge-check { padding-block: clamp(3.5rem, 7vw, 6rem); border-bottom: 1px solid #30313a; }
  .lesson-objectives h2,
  .lesson-chapter h2,
  .lesson-practice h2,
  .lesson-notes h2,
  .knowledge-check h2,
  .lesson-finish h2 { max-width: 16ch; margin-top: .8rem; font-size: clamp(2rem, 4vw, 3.6rem); }
  .lesson-objective-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 2rem; padding: 0; background: #30313a; list-style: none; }
  .lesson-objective-list li { min-height: 10rem; padding: 1.2rem; background: #111218; color: #c7c7cd; font-size: .78rem; line-height: 1.55; }
  .lesson-objective-list li::before { display: block; margin-bottom: 2rem; color: var(--lesson-accent); font: 500 .7rem/1 var(--font-mono); content: "✓"; }
  .lesson-prose { display: grid; gap: 1.2rem; margin-top: 2rem; }
  .lesson-prose p { max-width: 68ch; color: #bbbcc4; font-size: clamp(.92rem, 1.3vw, 1.06rem); line-height: 1.8; }
  .lesson-callout { display: grid; grid-template-columns: auto 1fr; gap: 1.5rem; align-items: start; margin-block: 1.5rem; padding: 2rem; border: 1px solid color-mix(in oklch, var(--lesson-accent) 45%, #30313a); background: color-mix(in oklch, var(--lesson-accent) 7%, #111218); }
  .lesson-callout-mark { color: var(--lesson-accent); font-size: 1.5rem; }
  .lesson-callout strong { display: block; max-width: 32ch; margin-top: .6rem; font-size: clamp(1.2rem, 2.4vw, 1.8rem); line-height: 1.25; letter-spacing: -.035em; }
  .lesson-example { overflow: hidden; margin-top: 2rem; border: 1px solid #33353f; border-radius: .8rem; background: #090a0e; }
  .lesson-example-bar { display: flex; justify-content: space-between; padding: .7rem 1rem; border-bottom: 1px solid #33353f; color: #777985; font: .58rem/1 var(--font-mono); text-transform: uppercase; }
  .lesson-example-bar button { border: 0; background: none; color: var(--lesson-accent); cursor: pointer; }
  .lesson-example pre { overflow-x: auto; padding: 1.4rem; color: #d8d7d3; font: .72rem/1.7 var(--font-mono); }
  .practice-mission { max-width: 45rem; margin-top: 1.5rem; color: #c5c5cc; font-size: 1rem; }
  .practice-steps { display: grid; gap: 0; margin-top: 2rem; padding: 0; border-top: 1px solid #30313a; list-style: none; counter-reset: practice; }
  .practice-steps li { display: grid; grid-template-columns: 3rem 1fr; gap: 1rem; padding-block: 1.2rem; border-bottom: 1px solid #30313a; color: #a8a9b1; font-size: .8rem; counter-increment: practice; }
  .practice-steps li::before { color: var(--lesson-accent); font: .62rem/1.5 var(--font-mono); content: "0" counter(practice); }
  .definition-done { display: grid; grid-template-columns: auto 1fr; gap: 1rem; margin-top: 2rem; padding: 1.2rem; border-left: 3px solid var(--lesson-accent); background: #15161c; }
  .definition-done > span { color: var(--lesson-accent); }
  .definition-done strong { font-size: .8rem; }
  .definition-done p { margin-top: .35rem; color: #8e909a; font-size: .72rem; }
  .studio-workspace {
    container-type: inline-size;
    overflow: hidden;
    margin-top: 2.5rem;
    border: 1px solid #3a3c46;
    border-radius: 1rem;
    background:
      linear-gradient(140deg, color-mix(in oklch, var(--lesson-accent) 5%, transparent), transparent 28rem),
      #0a0b0f;
    box-shadow: 0 2rem 5rem rgb(0 0 0 / .22);
  }
  .workspace-loading { padding: 3rem; color: #858791; font: .7rem/1.4 var(--font-mono); }
  .workspace-head {
    display: flex;
    justify-content: space-between;
    gap: 1.5rem;
    align-items: end;
    padding: 1.4rem;
    border-bottom: 1px solid #30313a;
  }
  .workspace-eyebrow { color: var(--lesson-accent); font: .58rem/1 var(--font-mono); letter-spacing: .08em; text-transform: uppercase; }
  .workspace-head h3 { margin-top: .55rem; font-size: clamp(1.35rem, 3cqi, 2rem); letter-spacing: -.04em; }
  .workspace-state {
    flex: 0 0 auto;
    border: 1px solid #434550;
    border-radius: 100vw;
    padding: .55rem .75rem;
    color: #898b95;
    font: .55rem/1 var(--font-mono);
  }
  .workspace-state.is-ready { border-color: var(--lesson-accent); color: var(--lesson-accent); }
  .workspace-state.is-submitted { border-color: #6cf0b2; color: #8ef1c0; }
  .workspace-readiness { height: 3px; background: #202129; }
  .workspace-readiness span { display: block; width: 0; height: 100%; background: var(--lesson-accent); transition: width .25s ease; }
  .lesson-code-lab { border-bottom: 1px solid #30313a; }
  .lesson-code-bar {
    display: flex;
    min-height: 3.25rem;
    justify-content: space-between;
    gap: .75rem;
    align-items: center;
    padding: .5rem .7rem;
    border-bottom: 1px solid #30313a;
    background: #111218;
  }
  .lesson-code-tabs,
  .workspace-preview-sizes { display: flex; gap: .25rem; align-items: center; }
  .lesson-code-tabs button,
  .workspace-preview-sizes button,
  .workspace-mini-action {
    border: 1px solid transparent;
    border-radius: .35rem;
    padding: .5rem .65rem;
    background: transparent;
    color: #777985;
    font: 600 .55rem/1 var(--font-mono);
    cursor: pointer;
  }
  .lesson-code-tabs button:hover,
  .workspace-preview-sizes button:hover { color: #f4f1e8; }
  .lesson-code-tabs button.is-active,
  .workspace-preview-sizes button.is-active { border-color: #454750; background: #1a1b22; color: var(--lesson-accent); }
  .workspace-mini-action { margin-left: auto; border-color: var(--lesson-accent); color: var(--lesson-accent); }
  .lesson-code-stage { display: grid; min-height: 31rem; }
  .lesson-code-editor { position: relative; min-width: 0; border-bottom: 1px solid #30313a; background: #0d0e13; }
  .workspace-code-input {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    resize: none;
    border: 0;
    outline: 0;
    padding: 1.2rem;
    background:
      linear-gradient(90deg, #14151b 2.4rem, transparent 2.4rem),
      repeating-linear-gradient(#0d0e13 0 1.65rem, #15161c 1.65rem calc(1.65rem + 1px));
    color: #d7d6d2;
    caret-color: var(--lesson-accent);
    tab-size: 2;
    font: .68rem/1.65rem var(--font-mono);
  }
  .workspace-code-input:focus-visible { box-shadow: inset 0 0 0 2px var(--lesson-accent); }
  .lesson-code-preview { display: grid; min-width: 0; padding: 1rem; place-items: center; background: #181920; }
  .lesson-code-preview iframe {
    width: 100%;
    height: 100%;
    min-height: 29rem;
    border: 0;
    border-radius: .5rem;
    background: white;
    transition: width .3s cubic-bezier(.2,.8,.2,1);
  }
  .lesson-code-preview[data-preview-size="compact"] iframe { width: min(100%, 24rem); }
  .workspace-record { display: grid; gap: 1px; background: #30313a; }
  .workspace-field {
    display: grid;
    grid-template-columns: 2.5rem 1fr;
    gap: 1rem;
    padding: 1.4rem;
    background: #0d0e13;
  }
  .workspace-field-number { color: var(--lesson-accent); font: .58rem/1.4 var(--font-mono); }
  .workspace-field-copy strong { display: block; font-size: .85rem; }
  .workspace-field-copy small { display: block; max-width: 62ch; margin-top: .45rem; color: #898b95; font-size: .68rem; line-height: 1.55; }
  .workspace-field textarea {
    grid-column: 2;
    width: 100%;
    min-height: 8rem;
    resize: vertical;
    border: 1px solid #3b3d47;
    border-radius: .55rem;
    outline: 0;
    padding: 1rem;
    background: #111218;
    color: #f4f1e8;
    font: .76rem/1.65 var(--font-mono);
    field-sizing: content;
  }
  .workspace-field textarea:focus-visible { border-color: var(--lesson-accent); box-shadow: 0 0 0 3px color-mix(in oklch, var(--lesson-accent) 15%, transparent); }
  .workspace-review { display: grid; gap: 1.5rem; padding: 1.4rem; background: #111218; }
  .workspace-checks { display: grid; gap: .55rem; padding: 0; list-style: none; }
  .workspace-checks li {
    display: grid;
    grid-template-columns: 1.3rem 1fr;
    gap: .65rem;
    align-items: start;
    color: #777985;
    font: .62rem/1.45 var(--font-mono);
  }
  .workspace-checks li::before {
    display: grid;
    width: 1.1rem;
    aspect-ratio: 1;
    place-items: center;
    border: 1px solid #4a4c56;
    border-radius: 50%;
    color: #777985;
    content: "·";
  }
  .workspace-checks li.is-ready { color: #c8c9ce; }
  .workspace-checks li.is-ready::before { border-color: var(--lesson-accent); background: var(--lesson-accent); color: #111218; content: "✓"; }
  .workspace-actions { display: flex; flex-wrap: wrap; gap: .65rem; }
  .workspace-actions .button { min-height: 2.8rem; }
  .workspace-actions [data-submit-workspace] { margin-left: auto; }
  .workspace-actions [data-submit-workspace]:disabled { cursor: not-allowed; opacity: .4; transform: none; }
  @container (width > 46rem) {
    .lesson-code-stage { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
    .lesson-code-editor { border-right: 1px solid #30313a; border-bottom: 0; }
    .workspace-review { grid-template-columns: minmax(18rem, 1fr) auto; align-items: end; }
  }
  .lesson-notes > div > p:last-child { margin-top: .7rem; color: #797b86; font-size: .72rem; }
  .lesson-notes textarea { width: 100%; margin-top: 2rem; resize: vertical; border: 1px solid #3a3c46; border-radius: .7rem; padding: 1rem; background: #111218; color: #f4f1e8; font: .8rem/1.6 var(--font-mono); field-sizing: content; }
  .note-status { display: block; margin-top: .5rem; color: #72747f; font: .58rem/1 var(--font-mono); text-align: right; }
  .quiz-question { max-width: 48rem; margin-top: 1.5rem; color: #c7c8ce; font-size: 1rem; }
  .quiz-options { display: grid; gap: .7rem; margin-top: 1.5rem; border: 0; padding: 0; }
  .quiz-options label { display: grid; grid-template-columns: auto 2rem 1fr; gap: .8rem; align-items: center; padding: 1rem; border: 1px solid #393b45; border-radius: .65rem; cursor: pointer; }
  .quiz-options label:has(input:checked) { border-color: var(--lesson-accent); background: color-mix(in oklch, var(--lesson-accent) 7%, transparent); }
  .quiz-options input { width: 1rem; height: 1rem; accent-color: var(--lesson-accent); }
  .quiz-options span { display: grid; width: 1.7rem; aspect-ratio: 1; place-items: center; border: 1px solid #484a55; border-radius: 50%; color: #858792; font: .58rem/1 var(--font-mono); }
  .quiz-options strong { font-size: .78rem; font-weight: 600; }
  .check-answer { margin-top: 1.5rem; }
  .quiz-feedback { min-height: 3rem; margin-top: 1rem; padding: .9rem 1rem; border-radius: .5rem; color: #989aa4; font-size: .75rem; }
  .quiz-feedback:empty { display: none; }
  .quiz-feedback.is-correct { background: rgb(108 240 178 / .1); color: #8ef1c0; }
  .quiz-feedback.is-incorrect { background: rgb(255 92 57 / .1); color: #ff947c; }
  .lesson-finish { display: grid; grid-template-columns: 1fr auto; gap: 2rem; align-items: end; padding-block: clamp(3rem, 6vw, 5rem); }
  .lesson-finish > div > p:last-child { max-width: 36rem; margin-top: 1rem; color: #898b95; font-size: .78rem; }
  .complete-lesson:disabled { cursor: not-allowed; opacity: .35; transform: none; }
  .lesson-pager { display: grid; grid-template-columns: 1fr 1fr; width: 100%; max-width: none; border-top: 1px solid #30313a; }
  .lesson-pager button { display: grid; grid-template-columns: auto 1fr auto; gap: 1rem; min-height: 8rem; align-items: center; padding: 1.5rem clamp(1rem, 4vw, 3rem); border: 0; border-right: 1px solid #30313a; background: #111218; color: #f4f1e8; text-align: left; cursor: pointer; }
  .lesson-pager button:last-child { border-right: 0; text-align: right; }
  .lesson-pager button:hover { background: #181920; }
  .lesson-pager button[hidden] { display: block; visibility: hidden; }
  .lesson-pager small { color: var(--lesson-accent); font: .58rem/1 var(--font-mono); text-transform: uppercase; }
  .lesson-pager strong { font-size: .78rem; }

  .search-dialog { width: min(50rem, calc(100% - 2rem)); margin: 6vh auto auto; }
  .search-shell { overflow: hidden; border: 1px solid #3a3c46; border-radius: 1rem; background: #121318; color: #f4f1e8; box-shadow: 0 3rem 10rem rgb(0 0 0 / .6); }
  .search-top { display: grid; grid-template-columns: auto 1fr auto; gap: 1rem; align-items: center; min-height: 4.5rem; padding-inline: 1.2rem; border-bottom: 1px solid #30313a; }
  .search-top > span { color: var(--acid); font-size: 1.5rem; }
  .search-top input { width: 100%; border: 0; outline: 0; background: transparent; color: #f4f1e8; font-size: 1rem; }
  .search-top input::placeholder { color: #777985; }
  .search-close { padding: .4rem .5rem; border: 1px solid #3b3d47; border-radius: .35rem; background: #1b1c23; color: #92939d; font: .58rem/1 var(--font-mono); cursor: pointer; }
  .search-help { display: flex; justify-content: space-between; gap: 1rem; padding: .8rem 1.2rem; color: #747681; font: .6rem/1.4 var(--font-mono); }
  .search-results { max-height: 60vh; overflow: auto; padding: .5rem; }
  .search-result { display: grid; grid-template-columns: 6rem 1fr auto; gap: 1rem; align-items: center; width: 100%; padding: 1rem; border: 0; border-radius: .6rem; background: none; color: #f4f1e8; text-align: left; cursor: pointer; }
  .search-result:hover, .search-result:focus-visible { background: #1e2028; }
  .result-type { color: var(--acid); font: .6rem/1 var(--font-mono); text-transform: uppercase; }
  .search-result strong { display: block; font-size: .86rem; }
  .search-result small { display: block; margin-top: .25rem; color: #80828d; font-size: .68rem; }
  .search-result i { color: var(--acid); font-style: normal; }
  .empty-search { padding: 3rem 1rem; color: #878993; text-align: center; }
  .noscript { position: fixed; z-index: 1000; inset: auto 1rem 1rem; padding: 1rem; background: var(--coral); color: #0b0b0e; font-weight: 800; text-align: center; }
}

@layer motion {
  @keyframes pop-in { from { opacity: 0; transform: translateY(-.5rem) scale(.96); } }
  @keyframes dialog-in { from { opacity: 0; transform: translateY(1rem) scale(.985); } }
  @keyframes ticker { to { transform: translateX(-50%); } }

  @supports (animation-timeline: scroll()) {
    .reading-line {
      animation: reading-progress linear both;
      animation-timeline: scroll(root);
    }
    @keyframes reading-progress { to { scale: 1 1; } }

    .reveal {
      animation: reveal-up both;
      animation-timeline: view();
      animation-range: entry 5% cover 35%;
    }
    @keyframes reveal-up {
      from { opacity: .15; transform: translateY(2.5rem); filter: blur(5px); }
      to { opacity: 1; transform: translateY(0); filter: blur(0); }
    }

    .feature-row {
      animation: row-enter both;
      animation-timeline: view();
      animation-range: entry 0% cover 25%;
    }
    @keyframes row-enter { from { opacity: .25; transform: translateX(-1.5rem); } }
  }

  @media (prefers-reduced-motion: no-preference) {
    .orbit-one { animation: orbit 18s linear infinite; }
    .orbit-two { animation: orbit 12s linear infinite reverse; }
    @keyframes orbit { to { rotate: 1turn; } }
  }
}

@layer utilities {
  .sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    clip-path: inset(50%);
  }

  @container (width < 500px) {
    .path-card h3 { font-size: 2.3rem; }
  }

  @media (max-width: 980px) {
    .site-header { grid-template-columns: 1fr auto; }
    .site-header nav { display: none; }
    .header-actions { grid-column: 2; }
    .search-trigger kbd { display: none; }
    .hero-title { line-height: .86; }
    .hero-footer { grid-template-columns: 1fr; }
    .section-heading, .now-header, .lab, .proof-head, .notes-heading { grid-template-columns: 1fr; }
    .manifesto { grid-template-columns: 1fr; }
    .method-loop { grid-template-columns: 1fr 1fr; }
    .method-loop li:nth-child(2) { border-right: 0; }
    .path-card, .path-card:nth-child(n) { grid-column: span 6; }
    .path-card:nth-child(1) { grid-column: 1 / -1; }
    .feature-row { grid-template-columns: .3fr 1fr; }
    .feature-row p { grid-column: 2; }
    .baseline-badge { grid-column: 2; justify-self: start; }
    .lab-intro { position: static; }
    .proof-strip { grid-template-columns: 1fr 1fr; }
    .proof-strip article:nth-child(2) { border-right: 0; }
    .proof-strip article:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
    .notes-list a { grid-template-columns: .3fr 1fr auto; }
    .notes-list p { grid-column: 2; }
    .site-footer { grid-template-columns: 1fr; text-align: left; }
    .site-footer p { text-align: left; }
    .site-footer > div { justify-content: flex-start; }
    .lesson-layout { grid-template-columns: 1fr; }
    .lesson-rail { display: none; }
  }

  @media (max-width: 720px) {
    :root { --page: min(100% - 1.25rem, 1440px); }
    .site-header { min-height: 4.5rem; }
    .progress-pill { display: none; }
    .hero { padding-top: 8rem; }
    .hero-kicker, .hero-title .line-two, .hero-footer { margin-left: 0; }
    .hero-title { font-size: clamp(3.2rem, 17vw, 6rem); }
    .hero-footer { margin-right: 0; }
    .hero-cta { flex-direction: column; align-items: stretch; }
    .hero-specimen { width: 100%; }
    .capability-grid { grid-template-columns: 1fr; }
    .orbit-one { width: 70vw; right: -20%; }
    .orbit-two { width: 45vw; right: -8%; }
    .method-loop { grid-template-columns: 1fr; }
    .method-loop li { min-height: 10rem; border-right: 0; border-bottom: 1px solid var(--line); }
    .method-loop span { margin-top: 2.5rem; }
    .path-card, .path-card:nth-child(n) { grid-column: 1 / -1; min-height: 31rem; }
    .now { padding-inline: .625rem; }
    .feature-row { grid-template-columns: 1fr; gap: .7rem; }
    .feature-row p, .baseline-badge { grid-column: 1; }
    .playground-bar { grid-template-columns: 1fr; gap: .7rem; padding-block: .7rem; }
    .traffic-lights, .preview-sizes { display: none; }
    .editor-tabs { overflow-x: auto; }
    .editor-tabs button { min-height: 2.5rem; flex: 1; }
    .playground-stage { grid-template-columns: 1fr; }
    .editor-pane { border-right: 0; border-bottom: 1px solid #2c2d35; }
    .code-editor { min-height: 22rem; }
    .preview-pane { min-height: 26rem; }
    .lab-frame { min-height: 23rem; }
    .proof-strip { grid-template-columns: 1fr; }
    .proof-strip article { min-height: 14rem; border-right: 0; border-bottom: 1px solid var(--line); }
    .proof-strip article:nth-child(n) { border-bottom: 1px solid var(--line); }
    .proof-strip h3 { margin-top: 3.5rem; }
    .notes-list a { grid-template-columns: 1fr auto; gap: .65rem; padding-block: 1.2rem; }
    .notes-list a > span, .notes-list p { grid-column: 1; }
    .notes-list i { grid-column: 2; grid-row: 1 / 4; }
    .closing h2 { font-size: clamp(2.8rem, 14vw, 5rem); }
    .dialog-shell { grid-template-columns: 1fr; }
    .dialog-sidebar { min-height: auto; border-right: 0; border-bottom: 1px solid #2d2f38; }
    .dialog-symbol { width: 4rem; margin-block: 2rem 1rem; }
    .dialog-progress { margin-top: 2rem; }
    .search-help span:last-child { display: none; }
    .search-result { grid-template-columns: 4.5rem 1fr auto; }
    .lesson-header { grid-template-columns: 1fr auto; min-height: 4rem; }
    .lesson-header-progress { display: none; }
    .lesson-layout { height: calc(100% - 4rem); }
    .lesson-reader > * { width: min(100% - 1.25rem, 52rem); }
    .lesson-hero { padding-top: 3.5rem; }
    .lesson-objective-list { grid-template-columns: 1fr; }
    .lesson-objective-list li { min-height: 7rem; }
    .lesson-objective-list li::before { margin-bottom: 1.2rem; }
    .lesson-meta { grid-template-columns: 1fr; }
    .lesson-meta div { border-right: 0; border-bottom: 1px solid #30313a; }
    .lesson-meta div:last-child { border-bottom: 0; }
    .lesson-callout { width: min(100% - 1.25rem, 52rem); padding: 1.3rem; }
    .workspace-head { align-items: start; flex-direction: column; }
    .lesson-code-bar { flex-wrap: wrap; }
    .workspace-preview-sizes { display: none; }
    .workspace-field { grid-template-columns: 1.8rem 1fr; padding: 1rem; }
    .workspace-actions { display: grid; }
    .workspace-actions [data-submit-workspace] { margin-left: 0; }
    .lesson-finish { grid-template-columns: 1fr; }
    .lesson-finish .button { justify-self: start; }
    .lesson-pager button { min-height: 7rem; padding: 1rem; }
    .lesson-pager strong { display: none; }
  }

  @media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
      scroll-behavior: auto !important;
      animation-duration: .01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: .01ms !important;
    }
    .feature-ticker div { animation: none; }
  }

  @media (forced-colors: active) {
    .hero-title em, .closing h2 span { color: CanvasText; -webkit-text-stroke: 0; }
    .status-light, .progress-dot { border: 1px solid CanvasText; }
  }
}