/* Chalkmind landing site. No frameworks, no web fonts. */
:root {
  --board: #0b3b35;
  --board-2: #105e50;
  --board-3: #0e4c43;
  --chalk: #f8fafc;
  --chalk-dim: #c9ddd6;
  --yellow: #facc15;
  --paper: #fbf8f1;
  --paper-2: #f3eee2;
  --ink: #14201d;
  --ink-2: #4a5955;
  --line: #e4ddcc;
  --green: #0f766e;
  --radius: 14px;
  --max: 1120px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--green); text-underline-offset: 3px; }
a:hover { color: var(--board); }
:focus-visible { outline: 3px solid var(--yellow); outline-offset: 3px; border-radius: 6px; }
h1, h2, h3 { line-height: 1.12; letter-spacing: -0.02em; margin: 0 0 .5em; }
h1 { font-size: clamp(2.3rem, 5.6vw, 4rem); font-weight: 800; }
h2 { font-size: clamp(1.75rem, 3.6vw, 2.6rem); font-weight: 800; }
h3 { font-size: 1.2rem; font-weight: 700; letter-spacing: -0.01em; }
p { margin: 0 0 1em; }
.wrap { width: min(100% - 32px, var(--max)); margin-inline: auto; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--yellow); color: var(--ink); padding: 8px 12px; border-radius: 8px; z-index: 10; }
.skip:focus { left: 8px; }

/* Header */
.site-header { background: var(--board); color: var(--chalk); }
.nav { display: flex; align-items: center; gap: 24px; padding: 18px 0; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--chalk); text-decoration: none; font-weight: 800; font-size: 1.2rem; letter-spacing: -0.02em; }
.brand svg { width: 34px; height: 34px; }
.nav-links { display: flex; gap: 22px; margin-left: auto; list-style: none; padding: 0; margin-block: 0; }
.nav-links a { color: var(--chalk-dim); text-decoration: none; font-size: .95rem; }
.nav-links a:hover { color: var(--chalk); }
@media (max-width: 760px) { .nav-links { display: none; } .nav .btn { margin-left: auto; } }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 10px; font: 600 1rem/1 var(--font); padding: 14px 20px; border-radius: 12px; text-decoration: none; border: 2px solid transparent; cursor: pointer; transition: transform .15s ease, background-color .15s ease; }
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--yellow); color: #14201d; }
.btn-primary:hover { background: #fde047; color: #14201d; }
.btn-ghost { border-color: rgba(248, 250, 252, .35); color: var(--chalk); }
.btn-ghost:hover { border-color: var(--chalk); color: var(--chalk); }
.btn-small { padding: 10px 14px; font-size: .92rem; }
.btn svg { width: 20px; height: 20px; flex: none; }

/* Hero */
.hero {
  background:
    radial-gradient(1200px 500px at 85% -10%, rgba(255, 255, 255, .07), transparent 60%),
    radial-gradient(800px 400px at -10% 110%, rgba(0, 0, 0, .25), transparent 60%),
    var(--board);
  color: var(--chalk);
  padding: 40px 0 88px;
  overflow: hidden;
}
.hero-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.eyebrow { display: inline-block; font-size: .85rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--yellow); margin-bottom: 18px; }
.hero h1 { color: var(--chalk); }
.hero h1 .ink { color: var(--yellow); }
.lede { font-size: 1.2rem; color: var(--chalk-dim); max-width: 34em; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin: 28px 0 18px; }
.fineprint { font-size: .9rem; color: var(--chalk-dim); opacity: .85; }
@media (max-width: 900px) { .hero-grid { grid-template-columns: 1fr; gap: 40px; } .hero { padding-bottom: 64px; } }

/* The demo board */
.board {
  position: relative;
  background:
    radial-gradient(400px 220px at 30% 20%, rgba(255, 255, 255, .05), transparent 70%),
    linear-gradient(160deg, #134f46, #0a302b);
  border-radius: 18px;
  border: 10px solid #5b3d22;
  box-shadow: 0 30px 60px rgba(0, 0, 0, .35), inset 0 0 40px rgba(0, 0, 0, .35);
  aspect-ratio: 520 / 360;
}
.board svg { width: 100%; height: 100%; }
.chalk { fill: none; stroke: var(--chalk); stroke-width: 3.2; stroke-linecap: round; stroke-linejoin: round; }
.chalk.answer { stroke: var(--yellow); stroke-width: 3.6; }
/* Drawn on scroll-into-view when JS is available; finished board without JS. */
.js .draw { stroke-dasharray: 1; stroke-dashoffset: 1; }
.js .play .draw { animation: draw .42s ease-out forwards; animation-delay: var(--d); }
@keyframes draw { to { stroke-dashoffset: 0; } }
.js .fade { opacity: 0; }
.js .play .fade { animation: fade .5s ease-out forwards; animation-delay: var(--d); }
@keyframes fade { to { opacity: 1; } }
.board-pill rect { fill: #f8fafc; }
.board-pill text { font: 700 15px var(--font); fill: #0b3b35; }
.board-note text { font: 500 16px var(--font); fill: var(--chalk-dim); }
.board-note .h { font-weight: 700; fill: var(--yellow); letter-spacing: .04em; }
@media (prefers-reduced-motion: reduce) {
  .js .draw, .js .play .draw { animation: none; stroke-dashoffset: 0; }
  .js .fade, .js .play .fade { animation: none; opacity: 1; }
}

/* Sections */
section { padding: 88px 0; }
.section-head { max-width: 46em; margin-bottom: 48px; }
.section-head p { color: var(--ink-2); font-size: 1.1rem; }
.kicker { font-size: .85rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--green); margin-bottom: 10px; display: block; }

.strip { background: var(--paper-2); border-block: 1px solid var(--line); padding: 22px 0; }
.strip ul { display: flex; flex-wrap: wrap; gap: 14px 34px; justify-content: center; list-style: none; margin: 0; padding: 0; font-weight: 600; color: var(--ink-2); font-size: .98rem; }
.strip li::before { content: "✓"; color: var(--green); font-weight: 800; margin-right: 8px; }

.feature { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; padding: 40px 0; }
.feature + .feature { border-top: 1px dashed var(--line); }
.feature:nth-child(even) .feature-visual { order: -1; }
.feature p { color: var(--ink-2); }
.feature ul { padding-left: 1.1em; color: var(--ink-2); margin: 0; }
.feature li { margin: .3em 0; }
@media (max-width: 860px) {
  .feature { grid-template-columns: 1fr; gap: 28px; }
  .feature:nth-child(even) .feature-visual { order: 0; }
}

/* Mock UI pieces (pure HTML/CSS, no images) */
.mock { color: var(--ink); background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: 0 18px 40px rgba(20, 32, 29, .09); padding: 18px; }
.mock-dark { background: var(--board-3); border-color: transparent; color: var(--chalk); }
.mock-title { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: .95rem; margin-bottom: 12px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.chip { font-size: .82rem; font-weight: 600; padding: 6px 11px; border-radius: 999px; background: var(--paper-2); color: var(--ink-2); border: 1px solid var(--line); }
.chip.on { background: #dff3ee; color: var(--board); border-color: #b9e1d7; }
.bubble { border-radius: 12px; padding: 12px 14px; font-size: .95rem; margin: 8px 0; }
.bubble.user { background: #e9f6f2; margin-left: 22%; }
.bubble.ai { background: var(--paper); border: 1px solid var(--line); }
.bubble .mark { background: rgba(250, 204, 21, .38); border-radius: 3px; padding: 0 2px; }

.paper { background: #fff; border: 1px solid var(--line); border-radius: 6px; padding: 22px 24px; font-family: Georgia, "Times New Roman", serif; font-size: 1rem; line-height: 1.75; color: #2b2b2b; box-shadow: 0 18px 40px rgba(20, 32, 29, .09); position: relative; }
.paper h4 { font-family: var(--font); margin: 0 0 8px; font-size: 1.1rem; }
.hl { background: rgba(250, 204, 21, .45); border-radius: 3px; padding: 0 2px; }
.lookup { position: relative; margin: 14px 0 0 auto; width: min(320px, 100%); background: #fff; color: #2b2b2b; border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; font-family: var(--font); font-size: .92rem; line-height: 1.5; box-shadow: 0 12px 30px rgba(20, 32, 29, .14); }
.lookup b { display: block; margin-bottom: 2px; }
.lookup .pos { color: #4a5955; font-style: italic; font-weight: 400; }
.lookup .acts { display: flex; gap: 8px; margin-top: 10px; }
.lookup .acts span { font-size: .8rem; font-weight: 700; padding: 5px 10px; border-radius: 8px; background: #f3eee2; color: #2b2b2b; }
.lookup .acts span.on { background: #105e50; color: #f8fafc; }

/* Audience */
.audience { background: var(--paper-2); border-block: 1px solid var(--line); }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; }
.card h3 { display: flex; align-items: center; gap: 10px; }
.card ul { margin: 0; padding-left: 1.1em; color: var(--ink-2); }
.card li { margin: .45em 0; }
@media (max-width: 760px) { .two-col { grid-template-columns: 1fr; } }

/* Steps */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; counter-reset: step; list-style: none; padding: 0; margin: 0; }
.steps li { counter-increment: step; padding-top: 8px; }
.steps li::before { content: counter(step); display: grid; place-items: center; width: 44px; height: 44px; border-radius: 50%; background: var(--board); color: var(--yellow); font-weight: 800; font-size: 1.2rem; margin-bottom: 14px; }
.steps p { color: var(--ink-2); }
@media (max-width: 760px) { .steps { grid-template-columns: 1fr; } }

/* Privacy band */
.privacy-band { background: var(--board); color: var(--chalk); }
.privacy-band p { color: var(--chalk-dim); max-width: 46em; }
.privacy-band a { color: var(--yellow); }

/* FAQ */
.faq details { border-bottom: 1px solid var(--line); padding: 18px 0; }
.faq summary { cursor: pointer; font-weight: 700; font-size: 1.08rem; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 1.4rem; line-height: 1; color: var(--green); }
.faq details[open] summary::after { content: "−"; }
.faq details p { color: var(--ink-2); margin: 10px 0 0; max-width: 52em; }

/* Final CTA */
.final { text-align: center; }
.final .cta-row { justify-content: center; }
.final .lede { margin-inline: auto; color: var(--ink-2); }

/* Footer */
.site-footer { background: #08241f; color: var(--chalk-dim); padding: 40px 0; font-size: .95rem; }
.foot { display: flex; flex-wrap: wrap; gap: 18px 32px; align-items: center; justify-content: space-between; }
.foot nav { display: flex; flex-wrap: wrap; gap: 20px; }
.site-footer a { color: var(--chalk-dim); }
.site-footer a:hover { color: var(--chalk); }

/* Long-form pages (privacy, terms, support) */
.doc { max-width: 760px; padding: 56px 0 88px; }
.doc h1 { font-size: clamp(2rem, 4vw, 2.8rem); }
.doc h2 { font-size: 1.4rem; margin-top: 2em; }
.doc .updated { color: var(--ink-2); font-size: .95rem; }
.doc li { margin: .35em 0; }

/* Dark mode for content areas (hero/footer are already dark) */
@media (prefers-color-scheme: dark) {
  :root { color-scheme: dark; --paper: #0f1714; --paper-2: #141f1b; --ink: #e8efec; --ink-2: #a9bab4; --line: #24332e; --green: #5eead4; }
  a:hover { color: var(--yellow); }
  .mock, .card { background: #16211d; }
  .lookup { border-color: #e4ddcc; }
  .paper { background: #f6f3ea; color: #2b2b2b; }
  .bubble.user { background: #18332c; }
  .chip.on { background: #18332c; color: #a7f3d0; border-color: #24524a; }
  .site-footer { background: #07130f; }
}