/* ==========================================================================
   dellream labs — landing
   ========================================================================== */

:root {
  --bg: #f6f6fb;
  --bg-elev: #ffffff;
  --surface: rgba(255, 255, 255, 0.72);
  --fg: #11131c;
  --muted: #5d6478;
  --line: rgba(17, 19, 28, 0.09);
  --accent: #5b4cf0;
  --accent-2: #0ea5c9;
  --accent-3: #e8891d;
  --accent-ink: #ffffff;
  --glow: rgba(91, 76, 240, 0.16);
  --contour: 91, 76, 240;

  --radius: 20px;
  --radius-sm: 12px;
  --container: 1160px;
  --gutter: clamp(16px, 4vw, 40px);
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --font: "Inter", -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-display: "Inter Display", -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0d12;
    --bg-elev: #12151d;
    --surface: rgba(22, 25, 34, 0.66);
    --fg: #eceef4;
    --muted: #8f97ab;
    --line: rgba(255, 255, 255, 0.08);
    --accent: #8f80ff;
    --accent-2: #4cc9f0;
    --accent-3: #ffb86b;
    --accent-ink: #0b0d12;
    --glow: rgba(143, 128, 255, 0.22);
    --contour: 143, 128, 255;
  }
}

/* ---------- base ---------- */

*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 400 17px/1.6 var(--font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* film grain */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 100;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

img, svg, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; font-family: var(--font-display); line-height: 1.1; letter-spacing: -0.025em; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection { background: var(--accent); color: var(--accent-ink); }

.container {
  width: 100%;
  max-width: calc(var(--container) + var(--gutter) * 2);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.container--narrow { max-width: calc(800px + var(--gutter) * 2); }

.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  z-index: 200;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--accent-ink);
  transition: top 0.2s;
}
.skip-link:focus { top: 16px; }

/* ---------- scroll progress ---------- */

.scroll-progress {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 60;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
  transform-origin: 0 50%;
  transform: scaleX(var(--progress, 0));
}

@supports (animation-timeline: scroll()) {
  .scroll-progress {
    animation: progress-grow linear both;
    animation-timeline: scroll(root block);
  }
  @keyframes progress-grow { from { transform: scaleX(0); } to { transform: scaleX(1); } }
}

/* ---------- buttons, misc ---------- */

.btn {
  --btn-bg: var(--fg);
  --btn-fg: var(--bg);
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-weight: 600;
  font-size: 16px;
  line-height: 1;
  white-space: nowrap;
  transition: transform 0.25s var(--ease-out), box-shadow 0.25s var(--ease-out), background-color 0.2s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 10px 30px -10px var(--glow), 0 0 0 6px var(--glow); }
.btn:active { transform: translateY(0); }
.btn span { transition: transform 0.25s var(--ease-out); }
.btn:hover span { transform: translateX(4px); }
.btn--ghost { --btn-bg: transparent; --btn-fg: var(--fg); border-color: var(--line); backdrop-filter: blur(8px); }
.btn--ghost:hover { border-color: var(--accent); }
.btn--small { padding: 10px 18px; font-size: 14px; }
.btn--large { padding: 18px 32px; font-size: 18px; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  color: var(--accent);
  font: 600 13px/1 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}

.gradient-text {
  background: linear-gradient(100deg, var(--accent) 0%, var(--accent-2) 35%, var(--accent-3) 65%, var(--accent) 100%);
  background-size: 300% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: gradient-shift 10s linear infinite;
}
@keyframes gradient-shift { to { background-position: 300% 0; } }

/* ---------- nav ---------- */

.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  transition: background-color 0.3s, border-color 0.3s, backdrop-filter 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom-color: var(--line);
}
.nav__inner {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 72px;
}
.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font: 700 18px/1 var(--font-display);
  letter-spacing: -0.02em;
}
.logo__mark { width: 26px; height: 26px; color: var(--accent); }
.logo__dim { color: var(--muted); font-weight: 500; margin-left: 4px; }

.nav__links {
  display: flex;
  gap: 4px;
  margin-left: auto;
}
.nav__links a {
  position: relative;
  padding: 8px 14px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s, background-color 0.2s;
}
.nav__links a:hover { color: var(--fg); }
.nav__links a.is-active { color: var(--fg); background: var(--line); }

.nav__burger {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  margin-left: 4px;
  border: 0;
  border-radius: 12px;
  background: transparent;
  color: var(--fg);
  cursor: pointer;
}
.nav__burger span {
  position: absolute;
  left: 12px;
  right: 12px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.3s var(--ease-out);
}
.nav__burger span:first-child { top: 17px; }
.nav__burger span:last-child { top: 25px; }
.nav.is-open .nav__burger span:first-child { transform: translateY(4px) rotate(45deg); }
.nav.is-open .nav__burger span:last-child { transform: translateY(-4px) rotate(-45deg); }

@media (max-width: 860px) {
  .nav__inner { gap: 12px; }
  .nav__cta { margin-left: auto; }
  .nav__burger { display: block; }
  .nav__links {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    padding: 8px var(--gutter) 20px;
    background: color-mix(in srgb, var(--bg) 94%, transparent);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.25s, transform 0.25s var(--ease-out), visibility 0.25s;
  }
  .nav.is-open .nav__links { opacity: 1; visibility: visible; transform: none; }
  .nav.is-open { background: color-mix(in srgb, var(--bg) 94%, transparent); }
  .nav__links a { padding: 14px 4px; font-size: 18px; border-radius: 0; border-bottom: 1px solid var(--line); }
  .nav__links a.is-active { background: none; color: var(--accent); }
}

/* ---------- hero ---------- */

.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 100vh;
  min-height: 100svh;
  padding: 120px 0 96px;
  overflow: hidden;
  isolation: isolate;
}
.hero__canvas {
  position: absolute;
  inset: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  cursor: crosshair;
}
.hero__glow {
  position: absolute;
  inset: -20% -10% auto auto;
  z-index: -2;
  width: 70vmax;
  height: 70vmax;
  border-radius: 50%;
  background: radial-gradient(closest-side, var(--glow), transparent 70%);
  filter: blur(20px);
  animation: float 18s ease-in-out infinite alternate;
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 160px;
  z-index: -1;
  background: linear-gradient(to bottom, transparent, var(--bg));
  pointer-events: none;
}
@keyframes float {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-12vw, 10vh) scale(1.15); }
}

.hero__content { pointer-events: none; }
.hero__content a, .hero__content button { pointer-events: auto; }

.hero__title {
  max-width: 14ch;
  font-size: clamp(44px, 7.4vw, 96px);
  font-weight: 750;
  line-height: 1.02;
  letter-spacing: -0.045em;
}
.hero__title .gradient-text { display: inline-block; padding-bottom: 0.08em; }
.hero__lead {
  max-width: 600px;
  margin-top: 28px;
  color: var(--muted);
  font-size: clamp(17px, 1.6vw, 20px);
  text-wrap: pretty;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 40px;
}
.hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 32px;
  margin-top: 56px;
  color: var(--muted);
  font-size: 15px;
}
.hero__facts strong {
  margin-right: 6px;
  color: var(--fg);
  font: 700 22px/1 var(--font-display);
}
.hero__hint {
  position: absolute;
  right: var(--gutter);
  bottom: 32px;
  color: var(--muted);
  font: 500 12px/1 var(--font-mono);
  letter-spacing: 0.04em;
  opacity: 0.7;
  pointer-events: none;
}
@media (hover: none) { .hero__hint { display: none; } }

/* ---------- marquee ---------- */

.marquee {
  overflow: hidden;
  padding: 22px 0;
  border-block: 1px solid var(--line);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
}
.marquee__track {
  display: flex;
  width: max-content;
  animation: marquee 40s linear infinite;
}
.marquee:hover .marquee__track { animation-play-state: paused; }
.marquee__list { display: flex; flex-shrink: 0; }
.marquee__list li {
  display: flex;
  align-items: center;
  gap: 28px;
  padding-right: 28px;
  color: var(--muted);
  font: 500 clamp(18px, 2vw, 24px)/1 var(--font-display);
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.marquee__list li::after {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.6;
}
@keyframes marquee { to { transform: translateX(-50%); } }

/* ---------- sections ---------- */

.section { position: relative; padding: clamp(88px, 12vw, 160px) 0; }
.section__head { max-width: 760px; margin-bottom: clamp(48px, 6vw, 72px); }
.section__title {
  font-size: clamp(34px, 4.6vw, 58px);
  font-weight: 720;
  letter-spacing: -0.035em;
  text-wrap: balance;
}
.section__lead {
  margin-top: 20px;
  color: var(--muted);
  font-size: clamp(17px, 1.4vw, 19px);
  text-wrap: pretty;
}

/* ---------- cards ---------- */

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
@media (max-width: 960px) { .cards { grid-template-columns: 1fr; } }

.card {
  --mx: 50%;
  --my: 50%;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  transition: border-color 0.3s, transform 0.4s var(--ease-out);
  transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
}
.card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(420px circle at var(--mx) var(--my), var(--glow), transparent 45%);
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}
.card:hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--line)); }
.card:hover::before { opacity: 1; }
.card > * { position: relative; }
.card__num {
  position: absolute;
  top: 28px;
  right: 30px;
  color: var(--muted);
  font: 500 13px/1 var(--font-mono);
}
.card__icon {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  margin-bottom: 8px;
  border-radius: 16px;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
}
.card__icon svg { width: 30px; height: 30px; }
.card h3 { font-size: 24px; font-weight: 680; }
.card p { color: var(--muted); }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; padding-top: 12px; }
.tags li {
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font: 500 13px/1.2 var(--font-mono);
}

/* ---------- math scrollytelling ---------- */

.math { background: linear-gradient(to bottom, transparent, color-mix(in srgb, var(--accent) 5%, transparent) 30%, transparent); }

.math__layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(32px, 6vw, 96px);
  align-items: start;
}
.math__steps { display: flex; flex-direction: column; }
.math__step {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
  min-height: 72vh;
  padding: 24px 0;
  opacity: 0.28;
  transition: opacity 0.5s var(--ease-out);
}
.math__step.is-active { opacity: 1; }
.math__step:first-child { min-height: 56vh; justify-content: flex-start; }
.math__step:last-child { min-height: 60vh; }
.math__label { color: var(--accent); font: 600 13px/1 var(--font-mono); letter-spacing: 0.06em; text-transform: uppercase; }
.math__step h3 { font-size: clamp(26px, 2.8vw, 36px); font-weight: 680; text-wrap: balance; }
.math__step p { color: var(--muted); font-size: 18px; max-width: 46ch; }
.formula {
  align-self: flex-start;
  margin-top: 8px;
  padding: 12px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface);
  font: 500 18px/1.2 var(--font-mono);
  color: var(--fg);
}

.math__figure {
  position: sticky;
  top: max(96px, calc(50vh - 260px));
  margin: 0;
}
.math__frame {
  position: relative;
  aspect-ratio: 1;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    radial-gradient(circle at 30% 20%, var(--glow), transparent 55%),
    var(--bg-elev);
  overflow: hidden;
  box-shadow: 0 40px 80px -40px rgba(0, 0, 0, 0.35);
}
.math__caption {
  margin-top: 16px;
  color: var(--muted);
  font: 500 13px/1 var(--font-mono);
  text-align: center;
}

.viz {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transform: scale(0.96);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}
.viz * { animation-play-state: paused; }
.math__figure[data-active="0"] .viz[data-viz="0"],
.math__figure[data-active="1"] .viz[data-viz="1"],
.math__figure[data-active="2"] .viz[data-viz="2"],
.math__figure[data-active="3"] .viz[data-viz="3"] { opacity: 1; transform: none; }
.math__figure[data-active="0"] .viz[data-viz="0"] *,
.math__figure[data-active="1"] .viz[data-viz="1"] *,
.math__figure[data-active="2"] .viz[data-viz="2"] *,
.math__figure[data-active="3"] .viz[data-viz="3"] * { animation-play-state: running; }

.stroke-a { stroke: var(--accent); }
.stroke-b { stroke: var(--accent-2); }
.fill-a { fill: var(--accent); }
.fill-b { fill: var(--accent-2); }

/* linear algebra */
.la-static line { stroke: var(--line); stroke-width: 1; }
.la-grid line.grid { stroke: color-mix(in srgb, var(--accent) 35%, transparent); stroke-width: 1; }
.la-grid .vec { stroke-width: 4; stroke-linecap: round; }
.la-grid {
  transform-box: view-box;
  transform-origin: 200px 200px;
  animation: la-transform 6s var(--ease-out) infinite alternate;
}
@keyframes la-transform {
  0%, 12% { transform: matrix(1, 0, 0, 1, 0, 0); }
  88%, 100% { transform: matrix(1.35, 0.35, 0.35, 1.05, 0, 0); }
}
.la-eigen {
  stroke: var(--accent-3);
  stroke-width: 2;
  stroke-dasharray: 6 8;
  opacity: 0;
  animation: la-eigen 6s ease-in-out infinite alternate;
}
@keyframes la-eigen { 0%, 50% { opacity: 0; } 85%, 100% { opacity: 0.9; } }

/* optimisation */
.opt-contours ellipse {
  fill: none;
  stroke: color-mix(in srgb, var(--accent) 45%, transparent);
  stroke-width: 1.5;
  transform: rotate(-18deg);
  transform-box: view-box;
  transform-origin: 230px 215px;
}
.opt-contours ellipse:nth-child(odd) { stroke: color-mix(in srgb, var(--accent-2) 40%, transparent); }
.opt-path {
  fill: none;
  stroke: var(--accent-3);
  stroke-width: 2.5;
  stroke-linejoin: round;
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: draw 5s var(--ease-out) infinite;
}
.opt-dot {
  fill: var(--accent-3);
  filter: drop-shadow(0 0 8px var(--accent-3));
  offset-path: path("M60 120 L118 290 L150 150 L184 262 L200 182 L216 240 L224 202 L230 215");
  offset-rotate: 0deg;
  animation: descend 5s var(--ease-out) infinite;
}
.opt-min { fill: var(--fg); }
@keyframes draw {
  0% { stroke-dashoffset: 1; }
  70%, 88% { stroke-dashoffset: 0; opacity: 1; }
  100% { stroke-dashoffset: 0; opacity: 0; }
}
@keyframes descend {
  0% { offset-distance: 0%; opacity: 1; }
  70%, 88% { offset-distance: 100%; opacity: 1; }
  100% { offset-distance: 100%; opacity: 0; }
}

/* probability */
.prob-bars rect {
  fill: color-mix(in srgb, var(--accent) 55%, transparent);
  transform-box: fill-box;
  transform-origin: 50% 100%;
  animation: bar-grow 4.5s var(--ease-out) infinite both;
}
.prob-curve {
  fill: none;
  stroke: var(--accent-3);
  stroke-width: 3;
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: draw 4.5s var(--ease-out) infinite;
}
.prob-axis { stroke: var(--muted); stroke-width: 1; opacity: 0.5; }
@keyframes bar-grow {
  0% { transform: scaleY(0); }
  45%, 90% { transform: scaleY(1); }
  100% { transform: scaleY(0); }
}

/* attention */
.attn-cell {
  fill: var(--accent);
  animation: attn 3.2s ease-in-out infinite alternate both;
}
.attn-label { fill: var(--muted); font: 500 13px var(--font-mono); }
@keyframes attn { from { fill-opacity: var(--a0, 0.1); } to { fill-opacity: var(--a1, 0.8); } }

/* inline copies of the visuals, used on narrow screens instead of the sticky figure */
.math__inline { display: none; }

@media (max-width: 860px) {
  .math__layout { grid-template-columns: 1fr; }
  .math__figure { display: none; }
  .math__step,
  .math__step:first-child,
  .math__step:last-child {
    min-height: 0;
    padding: 0 0 72px;
    opacity: 1;
  }
  .math__inline {
    display: block;
    width: 100%;
    max-width: 420px;
    margin-bottom: 12px;
  }
  .math__inline .math__frame { box-shadow: none; }
  .math__inline .viz { opacity: 1; transform: none; transition: none; }
  .math__step.is-active .math__inline .viz * { animation-play-state: running; }
}

/* ---------- demos ---------- */

.demo-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}
@media (max-width: 900px) { .demo-grid { grid-template-columns: 1fr; } }

.demo {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  min-width: 0;
}
.demo__head { display: flex; flex-direction: column; gap: 10px; }
.demo__head h3 { font-size: 21px; font-weight: 660; }
.demo__tag {
  align-self: flex-start;
  padding: 4px 10px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  color: var(--accent);
  font: 600 12px/1.3 var(--font-mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.demo__stage {
  position: relative;
  border: 1px solid var(--line);
  border-radius: 14px;
  background:
    radial-gradient(circle at 20% 0%, var(--glow), transparent 60%),
    var(--bg-elev);
  overflow: hidden;
}
.demo__canvas {
  width: 100%;
  aspect-ratio: 16 / 10;
  touch-action: pan-y;
}
.demo__canvas--wide { aspect-ratio: 16 / 9; cursor: ew-resize; }
@media (max-width: 520px) { .demo__canvas--wide { aspect-ratio: 1 / 1; } }

.demo__controls {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--muted);
  font-size: 14px;
}
.demo__controls label { flex-shrink: 0; }
.demo__controls output,
.demo__controls b {
  min-width: 3.2em;
  color: var(--fg);
  font: 600 14px/1 var(--font-mono);
  font-variant-numeric: tabular-nums;
}
.demo__controls input[type="range"] { flex: 1; min-width: 0; }

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  height: 28px;
  background: transparent;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  opacity: 0.85;
}
input[type="range"]::-moz-range-track {
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  margin-top: -8px;
  border: 3px solid var(--bg-elev);
  border-radius: 50%;
  background: var(--fg);
  box-shadow: 0 0 0 1px var(--line), 0 4px 10px rgba(0, 0, 0, 0.25);
  transition: transform 0.15s;
}
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border: 3px solid var(--bg-elev);
  border-radius: 50%;
  background: var(--fg);
}
input[type="range"]:active::-webkit-slider-thumb { transform: scale(1.15); }

.demo__btn {
  margin-left: auto;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--fg);
  font: 500 14px/1 var(--font);
  cursor: pointer;
  transition: border-color 0.2s;
}
.demo__btn:hover { border-color: var(--accent); }

.demo__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  color: var(--muted);
  font: 500 13px/1.4 var(--font-mono);
}
.demo__stats b { color: var(--fg); font-weight: 600; }
[data-out="verdict"] { font-weight: 600; color: var(--accent-2); }
[data-out="verdict"][data-state="warn"] { color: var(--accent-3); }
[data-out="verdict"][data-state="bad"] { color: #f0607a; }
.demo__caption { color: var(--muted); font-size: 15px; }

/* embeddings */
.demo__stage--svg { aspect-ratio: 4 / 3; }
.demo__svg { width: 100%; height: 100%; }
.embed__blob { fill: var(--accent); opacity: 0.06; }
.embed__word { cursor: pointer; outline: none; }
.embed__word circle { fill: var(--muted); transition: fill 0.3s, r 0.3s; }
.embed__word text { fill: var(--muted); font: 500 12px var(--font); transition: fill 0.3s; }
.embed__word:hover text, .embed__word:focus-visible text { fill: var(--fg); }
.embed__word.is-near circle { fill: var(--accent-2); r: 5.5; }
.embed__word.is-near text { fill: var(--fg); font-weight: 600; }
.embed__query {
  transition: transform 0.9s var(--ease-out);
}
.embed__query circle { fill: var(--accent-3); filter: drop-shadow(0 0 6px var(--accent-3)); }
.embed__query text { fill: var(--accent-3); font: 700 13px var(--font-mono); }
.embed__word text,
.embed__query text {
  paint-order: stroke;
  stroke: var(--bg-elev);
  stroke-width: 4px;
  stroke-linejoin: round;
}
.embed__link {
  stroke: var(--accent-2);
  stroke-width: 1.5;
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: draw-link 0.6s var(--ease-out) forwards;
}
@keyframes draw-link { to { stroke-dashoffset: 0; } }

/* next-token */
.demo__stage--tokens {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
  min-height: 0;
  aspect-ratio: 16 / 10;
  padding: 20px;
}
@media (max-width: 520px) { .demo__stage--tokens { aspect-ratio: auto; min-height: 280px; } }
.tokens__prompt {
  min-height: 2.9em;
  font: 500 clamp(16px, 1.6vw, 18px)/1.45 var(--font-mono);
}
.tokens__next { color: var(--accent-3); font-weight: 700; }
.tokens__caret {
  display: inline-block;
  width: 0.55em;
  height: 1.1em;
  margin-left: 2px;
  vertical-align: -0.2em;
  background: var(--accent);
  animation: caret 1s steps(1) infinite;
}
@keyframes caret { 50% { opacity: 0; } }
.tokens__list { display: grid; gap: 8px; }
.tokens__row {
  display: grid;
  grid-template-columns: minmax(6.5em, auto) 1fr 3.2em;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font: 500 13px/1.2 var(--font-mono);
  transition: color 0.3s;
}
.tokens__track { height: 10px; border-radius: 6px; background: var(--line); overflow: hidden; }
.tokens__bar {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transform-origin: left;
  transform: scaleX(var(--p, 0));
  transition: transform 0.6s var(--ease-out);
}
.tokens__pct { text-align: right; color: var(--fg); font-variant-numeric: tabular-nums; }
.tokens__row.is-picked { color: var(--fg); }
.tokens__row.is-picked .tokens__bar { background: var(--accent-3); }


/* ---------- timeline ---------- */

.timeline {
  --progress: 0;
  position: relative;
  display: grid;
  gap: 24px;
  padding-left: 48px;
  max-width: 860px;
}
.timeline::before,
.timeline::after {
  content: "";
  position: absolute;
  left: 11px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  border-radius: 2px;
}
.timeline::before { background: var(--line); }
.timeline::after {
  background: linear-gradient(to bottom, var(--accent), var(--accent-2), var(--accent-3));
  transform-origin: top;
  transform: scaleY(var(--progress));
}
.timeline__item {
  position: relative;
  padding: 28px 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}
.timeline__dot {
  position: absolute;
  left: -46px;
  top: 34px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--line);
  background: var(--bg);
  transition: border-color 0.4s, box-shadow 0.4s;
}
.timeline__item.is-passed .timeline__dot {
  border-color: var(--accent);
  box-shadow: 0 0 0 6px var(--glow);
}
.timeline__when { color: var(--accent); font: 600 13px/1 var(--font-mono); letter-spacing: 0.05em; text-transform: uppercase; }
.timeline__item h3 { margin: 12px 0 10px; font-size: 26px; font-weight: 680; }
.timeline__item > p:not([class]) { color: var(--muted); }
.timeline__project {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px dashed var(--line);
}
.timeline__project span {
  display: inline-block;
  margin-right: 10px;
  padding: 3px 10px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent-3) 18%, transparent);
  color: var(--accent-3);
  font: 600 12px/1.4 var(--font-mono);
  text-transform: uppercase;
}
@media (max-width: 600px) {
  .timeline { padding-left: 36px; }
  .timeline__dot { left: -34px; }
  .timeline::before, .timeline::after { left: 9px; }
  .timeline__item { padding: 24px 22px; }
}

/* ---------- format ---------- */

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin: 0 0 56px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  overflow: hidden;
}
.stat {
  display: flex;
  flex-direction: column-reverse;
  justify-content: flex-end;
  gap: 8px;
  padding: 32px 28px;
  background: var(--bg-elev);
}
.stat dd {
  margin: 0;
  font: 750 clamp(44px, 5vw, 64px)/1 var(--font-display);
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
}
.stat dt { color: var(--muted); }
@media (max-width: 860px) { .stats { grid-template-columns: repeat(2, 1fr); } }

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}
.feature { padding-top: 24px; border-top: 2px solid var(--fg); }
.feature h3 { margin-bottom: 12px; font-size: 21px; font-weight: 650; }
.feature p { color: var(--muted); }
@media (max-width: 860px) { .features { grid-template-columns: 1fr; gap: 32px; } }

/* ---------- faq ---------- */

.faq { border-top: 1px solid var(--line); }
.faq__item { border-bottom: 1px solid var(--line); }
.faq__item summary {
  position: relative;
  padding: 26px 48px 26px 0;
  font: 600 clamp(18px, 1.8vw, 21px)/1.35 var(--font-display);
  letter-spacing: -0.01em;
  list-style: none;
  cursor: pointer;
  transition: color 0.2s;
}
.faq__item summary::-webkit-details-marker { display: none; }
.faq__item summary:hover { color: var(--accent); }
.faq__item summary::after {
  content: "";
  position: absolute;
  right: 8px;
  top: 50%;
  width: 12px;
  height: 12px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: translateY(-75%) rotate(45deg);
  transition: transform 0.3s var(--ease-out);
}
.faq__item[open] summary::after { transform: translateY(-25%) rotate(-135deg); }
.faq__item p {
  padding: 0 48px 26px 0;
  color: var(--muted);
  font-size: 17px;
}
.faq__item[open] p { animation: faq-open 0.4s var(--ease-out); }
@keyframes faq-open { from { opacity: 0; transform: translateY(-6px); } }

/* ---------- cta ---------- */

.cta__box {
  position: relative;
  padding: clamp(48px, 8vw, 96px) clamp(24px, 6vw, 80px);
  border-radius: 32px;
  text-align: center;
  overflow: hidden;
  isolation: isolate;
  background: var(--bg-elev);
  border: 1px solid var(--line);
}
.cta__box::before {
  content: "";
  position: absolute;
  inset: -50%;
  z-index: -1;
  background: conic-gradient(from 0deg, var(--accent), var(--accent-2), var(--accent-3), var(--accent));
  opacity: 0.18;
  filter: blur(60px);
  animation: spin 16s linear infinite;
}
@keyframes spin { to { transform: rotate(1turn); } }
.cta__box h2 { font-size: clamp(36px, 5vw, 64px); font-weight: 750; letter-spacing: -0.04em; }
.cta__box p { max-width: 520px; margin: 18px auto 36px; color: var(--muted); font-size: 19px; }
.cta__box .btn { max-width: 100%; overflow: hidden; text-overflow: ellipsis; }

/* ---------- footer ---------- */

.footer { padding: 40px 0 48px; border-top: 1px solid var(--line); color: var(--muted); font-size: 15px; }
.footer__inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; }
.footer nav { display: flex; gap: 24px; }
.footer a:hover { color: var(--fg); }

/* ---------- reveal on scroll (only when JS is running) ---------- */

.js [data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  filter: blur(6px);
  transition:
    opacity 0.9s var(--ease-out) var(--delay, 0ms),
    transform 0.9s var(--ease-out) var(--delay, 0ms),
    filter 0.9s var(--ease-out) var(--delay, 0ms);
}
.js [data-reveal].is-visible { opacity: 1; transform: none; filter: none; }
/* cards keep their own tilt transform once revealed */
.js .card[data-reveal].is-visible { transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)); }
.js .card[data-reveal].is-visible { transition: opacity 0.9s var(--ease-out) var(--delay, 0ms), filter 0.9s var(--ease-out) var(--delay, 0ms), transform 0.4s var(--ease-out), border-color 0.3s; }

@media (hover: none) {
  .js [data-reveal] { filter: none; }
}

/* above the fold: play on load instead of waiting for IntersectionObserver */
.js .hero [data-reveal] {
  transition: none;
  animation: hero-in 1s var(--ease-out) var(--delay, 0ms) forwards;
}
@keyframes hero-in {
  from { opacity: 0; transform: translateY(28px); filter: blur(6px); }
  to { opacity: 1; transform: none; filter: none; }
}

/* ---------- reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .js [data-reveal] { opacity: 1; transform: none; filter: none; }
  .marquee__track, .viz * { animation: none !important; }
  .opt-path, .prob-curve { stroke-dashoffset: 0; }
  .opt-dot { offset-distance: 100%; }
  .math__step { opacity: 1; }
}

/* ---------- notes ---------- */

.article__back { display: inline-block; margin-bottom: 40px; color: var(--muted); font-size: 15px; }
.article__back:hover { color: var(--fg); }