/* What every page with motion shares: the font, the tokens, the knot, buttons, the top bar and the footer.
   home.css and details.css hold each page's own parts. */

@font-face {
  font-family: "Mona Sans";
  font-style: normal;
  font-display: swap;
  font-weight: 200 900;
  src: url(fonts/mona-sans-latin-wght.woff2) format("woff2-variations"), url(fonts/mona-sans-latin-wght.woff2) format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* The light's place on the knot (0 to 100, 84 is home) */
@property --p { syntax: "<number>"; inherits: true; initial-value: 84; }

:root {
  color-scheme: light dark;
  --bg: #fafafb;
  --bg-sunk: #f3f3f5;
  --bg-raise: #ffffff;
  --fg: #1b1b20;
  --fg-2: #4f4f58;
  --fg-3: #6b6b74;
  --rule: #e3e3e8;
  --rule-2: #cfcfd6;
  --accent: #7c4dd8;
  --accent-dim: rgba(124, 77, 216, 0.07);
  --accent-line: rgba(124, 77, 216, 0.35);
  /* the app's state colors: violet is live work, amber is waiting on you */
  --signal: #7a4aba;
  --signal: oklch(0.52 0.17 300);
  --warn: #a66000;
  --warn: oklch(0.555 0.13 65);
  --glow: 6%;
  --shadow: 0 1px 2px rgba(20, 20, 30, 0.04), 0 12px 32px rgba(20, 20, 30, 0.08);
  --lift: 0 2px 4px rgba(20, 20, 30, 0.06), 0 22px 48px rgba(20, 20, 30, 0.16);
  --sans: "Mona Sans", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --gutter: 32px;
  --max: 1160px;
  --top-h: 60px;
  /* motion, as the app's tokens */
  --ease-out: cubic-bezier(0.2, 0.7, 0.2, 1);
  --ease-morph: cubic-bezier(0.6, 0, 0.4, 1);
  --ease-settle: cubic-bezier(0.3, 0.05, 0.15, 1);
  --ease-io: cubic-bezier(0.65, 0, 0.35, 1);
  /* the mark: every <use href="#k"> reads these (base, light, halo, widths, light's dashes) */
  --k-dim: var(--rule-2);
  --kw: 5.2;
  --khw: 9;
  --kb: var(--fg);
  --kl: var(--signal);
  --kh: var(--bg);
  --klo: 1;
  --kda: 16 84;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141417;
    --bg-sunk: #111114;
    --bg-raise: #1a1a1e;
    --fg: #ecebef;
    --fg-2: #b4b3bc;
    --fg-3: #8f8e98;
    --rule: #29292f;
    --rule-2: #3a3a42;
    --accent: #b592f0;
    --accent-dim: rgba(181, 146, 240, 0.08);
    --accent-line: rgba(181, 146, 240, 0.4);
    --signal: #c6a2f7;
    --signal: oklch(0.775 0.125 303);
    --warn: #f2be62;
    --warn: oklch(0.83 0.125 80);
    --glow: 10%;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 16px 40px rgba(0, 0, 0, 0.35);
    --lift: 0 2px 4px rgba(0, 0, 0, 0.4), 0 24px 56px rgba(0, 0, 0, 0.55);
  }
}

* { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--top-h) + 16px);
  interpolate-size: allow-keywords;
}
.still { scroll-behavior: auto; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  font-weight: 420;
  font-synthesis: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  overflow-x: clip;
}
img { display: block; max-width: 100%; height: auto; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 3px; }
::selection { background: var(--accent-dim); }
b, strong { font-weight: 600; }
button { font: inherit; color: inherit; }
code {
  font-family: var(--mono);
  font-size: 0.86em;
  padding: 0.08em 0.3em;
  border-radius: 4px;
  background: var(--bg-sunk);
  border: 1px solid var(--rule);
  white-space: nowrap;
}
.defs { position: absolute; width: 0; height: 0; overflow: hidden; }
.sr { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; padding: 0; }

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.skip {
  position: absolute;
  left: 12px;
  top: -60px;
  padding: 8px 12px;
  background: var(--fg);
  color: var(--bg);
  border-radius: 6px;
  z-index: 30;
}
.skip:focus { top: 12px; }

/* ---------------------------------------------------------------- knots */

/* a drawn knot (base.js): base, light and halo from the custom properties above */
.rope { display: block; width: 100%; height: 100%; overflow: hidden; --rb: var(--kb); --rl: var(--kl); }
.rope[overflow="visible"] { overflow: visible; }
.rope .r-base { stroke: var(--rb); }
.rope .r-cap { fill: var(--rb); }
.rope .r-dim { stroke: var(--k-dim); }
.rope .r-dimcap { fill: var(--k-dim); }
.rope .r-lt, .rope .r-trail { stroke: var(--rl); }
/* the faint trail ends flat, so two pieces never overlap into darker dots */
.rope .r-trail { stroke-linecap: butt; }
.rope .r-lt { opacity: var(--lit, 1); }
.rope .r-halo { stroke: var(--kh); }
.rope[data-state="thinking"], .rope[data-state="tool"], .rope[data-state="waiting"], .rope[data-state="paused"] { --rb: var(--k-dim); }
.rope[data-state="waiting"] { --rl: var(--warn); }
.rope[data-state="paused"] { --rl: var(--fg-3); }
.rope[data-state="done"] { --rb: var(--fg-3); }

/* ---------------------------------------------------------------- buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 20px;
  border: 1px solid var(--fg);
  border-radius: 9px;
  background: var(--fg);
  color: var(--bg);
  font-weight: 560;
  font-size: 16px;
  line-height: 1.3;
  text-decoration: none;
  transition: opacity 120ms, transform 120ms, border-color 120ms;
}
.btn:hover { opacity: 0.88; }
.btn:active { transform: translateY(1px); }
.btn-quiet { background: transparent; color: var(--fg); border-color: var(--rule-2); }
.btn-quiet:hover { opacity: 1; border-color: var(--fg-3); }
.btn-sm { padding: 7px 14px; font-size: 14.5px; border-radius: 8px; }

/* the Download button's rim: one light laps the edge (the app's Rim). A conic light turns
   inside a masked ring, so it runs on the compositor: three laps after load, then on hover or focus */
.rim { position: relative; isolation: isolate; }
.rim-ring {
  display: none;
  position: absolute;
  inset: -3px;
  border-radius: 11px;
  padding: 1.5px;
  overflow: hidden;
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#000 0 0) content-box exclude, linear-gradient(#000 0 0);
  pointer-events: none;
}
.rim-ring i {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 220px;
  height: 220px;
  margin: -110px 0 0 -110px;
  background: conic-gradient(transparent 0 64%, var(--signal) 82%, transparent 96%);
}
.motion .rim-ring { display: block; animation: fade-late 12.2s linear both; }
.motion .rim-ring i { animation: rim 4s linear 3 both; }
.motion .rim:is(:hover, :focus-visible) .rim-ring { animation: none; }
.motion .rim:is(:hover, :focus-visible) .rim-ring i { animation: rim-hover 2.4s linear infinite; }
@keyframes rim { to { transform: rotate(1turn); } }
@keyframes rim-hover { to { transform: rotate(1turn); } }
@keyframes fade-late { 0%, 97% { opacity: 1; } 100% { opacity: 0; } }

/* ---------------------------------------------------------------- top bar */

.top {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg);
  border-bottom: 1px solid transparent;
  transition: border-color 240ms;
}
/* a frosted bar where it is cheap; phones get a plain one, so scrolling stays smooth */
@media (min-width: 1000px) {
  .top {
    background: color-mix(in srgb, var(--bg) 84%, transparent);
    -webkit-backdrop-filter: blur(16px);
    backdrop-filter: blur(16px);
  }
}
.top.scrolled { border-bottom-color: var(--rule); }
.top-row {
  display: flex;
  align-items: center;
  gap: 24px;
  height: var(--top-h);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--fg);
  text-decoration: none;
  font-weight: 600;
  font-size: 18px;
  letter-spacing: -0.01em;
  flex: none;
}
.mark { display: block; width: 24px; height: 24px; --kw: 7; --khw: 11; }
.top .mark { --kh: var(--bg); }
/* the mark's light runs one lap over the whole page as you read */
.motion .top .mark { animation: mark-lap linear both; animation-timeline: scroll(root); }
@keyframes mark-lap { from { --p: 84; } to { --p: 184; } }
@supports not (animation-timeline: scroll()) {
  .motion .top .mark { animation: none; --p: calc(84 + var(--scroll, 0) * 100); }
}
.sections { flex: 1; min-width: 0; }
.sections-row {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 28px;
  height: var(--top-h);
  overflow-x: auto;
  scrollbar-width: none;
  white-space: nowrap;
}
.sections-row::-webkit-scrollbar { display: none; }
.sections a {
  color: var(--fg-2);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 240ms;
}
.sections a:hover, .sections a[aria-current] { color: var(--fg); }
.ind {
  position: absolute;
  left: 0;
  bottom: 13px;
  width: 1px;
  height: 2px;
  background: var(--signal);
  transform-origin: 0 0;
  opacity: 0;
  pointer-events: none;
}
.motion .ind { transition: transform 240ms var(--ease-out), opacity 240ms; }
.top-end { display: flex; align-items: center; gap: 12px; flex: none; }
.pause {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  color: var(--fg-2);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
}
.pause:hover { color: var(--fg); border-color: var(--rule); }
.pause-label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.pause[hidden] { display: none; }
.pause svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.pause .i-play { display: none; fill: currentColor; stroke: none; }
.pause[aria-pressed="true"] .i-pause { display: none; }
.pause[aria-pressed="true"] .i-play { display: inline; }

/* ---------------------------------------------------------------- type */

h1 { text-wrap: balance; }
h2 {
  margin: 0;
  font-size: clamp(30px, 2.6vw + 12px, 48px);
  line-height: 1.06;
  font-weight: 640;
  letter-spacing: -0.035em;
  text-wrap: balance;
}
.intro {
  margin: 18px 0 0;
  max-width: 44em;
  font-size: 19px;
  color: var(--fg-2);
}
h3 {
  margin: 0;
  font-size: 22px;
  line-height: 1.25;
  font-weight: 600;
  letter-spacing: -0.015em;
}
h4 {
  margin: 0;
  font-size: 17px;
  line-height: 1.3;
  font-weight: 600;
}

/* ---------------------------------------------------------------- reveals */

.motion .rv:not(.in) { opacity: 0; transform: translateY(12px); }
.motion .rv {
  transition: opacity 480ms var(--ease-out), transform 480ms var(--ease-out), border-color 180ms, box-shadow 180ms;
  transition-delay: calc(var(--i, 0) * 50ms), calc(var(--i, 0) * 50ms), 0s, 0s;
}
/* keyboard focus lands on content that has not been revealed yet: show it at once */
.motion .rv:focus-within { opacity: 1; transform: none; transition: none; }
/* if base.js never runs, show everything anyway */
.motion:not(.live) .rv { animation: show 0s 1.5s forwards; }
@keyframes show { to { opacity: 1; transform: none; } }

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

.foot { position: relative; background: var(--bg-sunk); border-top: 1px solid var(--rule); --kh: var(--bg-sunk); }
.foot-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 32px;
  padding-top: 28px;
  padding-bottom: 32px;
  font-size: 14.5px;
  color: var(--fg-3);
}
.foot-row p { margin: 0; }
.foot-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--fg);
  font-weight: 600;
  font-size: 16px;
  text-decoration: none;
}
.foot-brand .mark { width: 20px; height: 20px; }
.foot-links { display: flex; flex-wrap: wrap; gap: 4px 24px; }
.foot-links a { color: var(--fg-2); text-decoration: none; }
.foot-links a:hover { color: var(--fg); text-decoration: underline; }

/* ---------------------------------------------------------------- loops pause in a hidden tab */

.tab-hidden *, .tab-hidden *::before, .tab-hidden *::after { animation-play-state: paused !important; }

/* ---------------------------------------------------------------- tablet */

@media (max-width: 999px) {
  :root { --gutter: 24px; --top-h: 56px; }
  html { scroll-padding-top: 116px; }
  .top-row { flex-wrap: wrap; height: auto; gap: 0 16px; }
  .brand { height: var(--top-h); }
  .top-end { margin-left: auto; }
  .sections { order: 3; flex-basis: 100%; margin: 0 calc(-1 * var(--gutter)); }
  .sections-row {
    justify-content: flex-start;
    height: 44px;
    padding: 0 var(--gutter);
    gap: 24px;
    border-top: 1px solid var(--rule);
    /* the row scrolls sideways when it must: its edges fade so the cut-off links read as more */
    -webkit-mask-image: linear-gradient(90deg, transparent, #000 16px, #000 calc(100% - 28px), transparent);
    mask-image: linear-gradient(90deg, transparent, #000 16px, #000 calc(100% - 28px), transparent);
  }
  .ind { bottom: 7px; }
}

/* ---------------------------------------------------------------- phone */

@media (max-width: 640px) {
  :root { --gutter: 16px; }
  body { font-size: 16px; }
  h2 { font-size: 32px; }
  .intro { font-size: 17px; }
  h3 { font-size: 20px; }
  .foot-row { flex-direction: column; align-items: flex-start; gap: 4px; }
  /* tap targets: 44px at least */
  .sections a { display: flex; align-items: center; justify-content: center; min-height: 44px; min-width: 44px; padding: 0 4px; }
  .pause { width: 44px; height: 44px; }
  .top .btn-sm { min-height: 44px; padding: 10px 14px; }
  .foot-brand, .foot-links a { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; min-width: 44px; }
  summary { padding-block: 11px; }
}

/* ---------------------------------------------------------------- reduced motion, belt and braces */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; transition-delay: 0ms !important; }
}