/* =============================================================================
   UIX landing site
   -----------------------------------------------------------------------------
   Order (and the architecture — see AGENTS.md):
     1. tokens            design + animation-timing custom properties
     2. reset
     3. a11y utilities
     4. base / static     the ACCESSIBLE DEFAULT. This is what reduced-motion
                          users get, and also the fallback when scroll-driven
                          animations aren't supported.
     5. motion            ALL animation lives behind
                          @media (prefers-reduced-motion: no-preference).
                          You physically cannot ship motion a user didn't opt
                          into, because it only exists inside that block.
     6. keyframes         grouped (they're global regardless of placement)

   Naming: BEM (block__element--modifier). The brand's SVG parts are
   .brand__u / .brand__stem / .brand__x, wrapped in .brand__center.
   ============================================================================= */

/* ---------- 1. tokens ---------- */
:root {
  --bg: #0f1012;
  --fg: #e8e8ea;
  --muted: #9a9aa2;
  --line: #2a2b2f;

  --bar-h: 56px; /* sticky bar height */
  --mark-h: 26vmin; /* brand full size */
  --mark-dock-h: 52px; /* brand docked / header size */
  --mark-bar-y: 4px; /* in-bar mark vertical nudge: + lowers, - raises (~2px headroom) */

  /* Motion-only: scroll-progress timing, measured from page top.
     Tune these to repace the morph + dock; nothing else needs touching. */
  --morph-end: 90vh; /* L1->L2->L3 finishes assembling around here */
  --l3-hold: 20vh; /* how long L3 sits still before it starts to rise */
  --dock-start: calc(var(--morph-end) + var(--l3-hold));
  /* rise scroll length == the top edge's travel distance, so the logo rises at
     exactly native scroll speed (1px of top per 1px of scroll), any aspect ratio */
  --rise-len: calc(50vh - var(--mark-h) / 2 - var(--bar-h));
  --shrink-len: 12vh; /* top-aligned shrink (bottom + sides come in) */
  --slide-len: 8vh; /* slide up into the bar */
  --rise-end: calc(var(--dock-start) + var(--rise-len));
  --shrink-end: calc(var(--rise-end) + var(--shrink-len));
  --dock-end: calc(var(--shrink-end) + var(--slide-len));
  --dock-tail: 40vh; /* empty runway after docking. 0 = mock scrolls in DURING
                            the rise; raise it for a settle after the dock instead */
}

/* Mobile retune. Only override the BASE inputs — the derived --dock-*/
/* runway recompute from these automatically. (Starting values; tweak to taste.) */
@media (max-width: 640px) {
  :root {
    --mark-h: 34vmin; /* logo reads small on narrow screens — bump it up */
    --morph-end: 60vh; /* shorter morph so it isn't a marathon scroll */
    --l3-hold: 14vh;
    --shrink-len: 12vh;
    --slide-len: 8vh;
  }
}

/* ---------- 2. reset ---------- */
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
} /* anchor clicks animate-scroll instead of jumping */
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font:
    16px/1.55 ui-sans-serif,
    system-ui,
    sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* ---------- 3. a11y utilities ---------- */
.u-visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 4. base / static (the accessible default) ---------- */

/* sticky bar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--bar-h);
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  border-top: 1px solid var(--line);
}
.topbar__brand {
  color: var(--fg);
  margin-top: var(--mark-bar-y); /* shared in-bar vertical nudge (see :root) */
}
.topbar__brand svg {
  display: block;
  height: var(--mark-dock-h);
  width: auto;
}

/* hero: the brand centered in the viewport below the bar; mock right after */
.hero {
  min-height: calc(100svh - var(--bar-h));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.brand {
  display: block;
  color: var(--fg);
  text-decoration: none;
}
.brand__mark {
  display: block;
  height: var(--mark-h);
  width: auto;
}

/* scroll hint, fixed to the viewport bottom */
.scroll-cue {
  position: fixed;
  z-index: 45;
  left: 50%;
  bottom: 1.5rem;
  translate: -50% 0;
  color: var(--muted);
  line-height: 0;
  padding: 0.5rem;
}
.scroll-cue:hover {
  color: var(--fg);
}
.scroll-cue svg {
  display: block;
}
/* opacity fade is fine under reduced motion, so it's gated on support only */
@supports (animation-timeline: scroll()) {
  .scroll-cue {
    animation: cue-fade linear both;
    animation-timeline: scroll(root);
    animation-range: 0 50svh; /* static page: fade out as you leave the hero */
  }
}

/* mock cockpit (theme demo) */
.stage {
  /* top-aligned so the mock window itself (not its empty centering space) is what
     scrolls into view as the brand rises */
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  max-width: 64rem;
  margin: 0 auto;
  padding: 4rem 1.25rem;
  scroll-margin-top: var(--bar-h);
}
.stage > .mock {
  width: 100%;
}
.mock {
  --m-bg: #16181d;
  --m-panel: #1d2026;
  --m-fg: #e9ebf0;
  --m-muted: #8b909c;
  --m-line: #2c2f37;
  --m-user: #2a3b55;
  --m-accent: #7aa2f7;
  background: var(--m-bg);
  color: var(--m-fg);
  border: 1px solid var(--m-line);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}
.mock[data-theme="paper"] {
  --m-bg: #f4f1ea;
  --m-panel: #fbfaf6;
  --m-fg: #24221d;
  --m-muted: #7c776c;
  --m-line: #ddd7c9;
  --m-user: #e3dcca;
  --m-accent: #b5651d;
}
.mock[data-theme="mono"] {
  --m-bg: #0a0a0a;
  --m-panel: #111;
  --m-fg: #f0f0f0;
  --m-muted: #777;
  --m-line: #2a2a2a;
  --m-user: #1f1f1f;
  --m-accent: #f0f0f0;
}
.mock__chrome {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.55rem 0.8rem;
  border-bottom: 1px solid var(--m-line);
  background: var(--m-panel);
}
.mock__dots {
  display: flex;
  gap: 0.35rem;
}
.mock__dots i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--m-line);
}
.mock__themes {
  margin-left: auto;
  display: flex;
  gap: 0.3rem;
}
.mock__themes button {
  font: inherit;
  font-size: 0.78rem;
  cursor: pointer;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  background: transparent;
  color: var(--m-muted);
  border: 1px solid var(--m-line);
}
.mock__themes button[aria-pressed="true"] {
  color: var(--m-bg);
  background: var(--m-accent);
  border-color: var(--m-accent);
}
.mock__body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 320px;
}
.mock__chat {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding: 1rem;
  border-right: 1px solid var(--m-line);
}
.msg {
  max-width: 85%;
  padding: 0.55rem 0.75rem;
  border-radius: 10px;
  font-size: 0.9rem;
}
.msg--user {
  align-self: flex-end;
  background: var(--m-user);
}
.msg--agent {
  align-self: flex-start;
  background: var(--m-panel);
  border: 1px solid var(--m-line);
}
.msg code {
  font-family: ui-monospace, monospace;
  font-size: 0.85em;
}
.mock__composer {
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--m-line);
  border-radius: 10px;
  color: var(--m-muted);
  font-size: 0.9rem;
}
.mock__composer kbd {
  border: 1px solid var(--m-line);
  border-radius: 4px;
  padding: 0 0.35rem;
}
.mock__canvas {
  display: flex;
  flex-direction: column;
  background: var(--m-panel);
}
.mock__canvasbar {
  padding: 0.5rem 0.8rem;
  border-bottom: 1px solid var(--m-line);
  color: var(--m-muted);
  font:
    0.8rem ui-monospace,
    monospace;
}
.mock__chart {
  flex: 1;
  display: flex;
  align-items: flex-end;
  gap: 0.5rem;
  padding: 1.2rem;
}
.mock__chart span {
  flex: 1;
  background: var(--m-accent);
  border-radius: 3px 3px 0 0;
  min-height: 4px;
}

@media (max-width: 640px) {
  .mock__body {
    grid-template-columns: 1fr;
  }
  .mock__chat {
    border-right: 0;
    border-bottom: 1px solid var(--m-line);
  }
}

/* ---------- 5. motion (only for users who haven't asked to reduce it) ---------- */
@media (prefers-reduced-motion: no-preference) {
  /* time-based bounce: works without scroll-timeline support */
  .scroll-cue svg {
    animation: cue-bounce 1.6s ease-in-out infinite;
  }

  /* scroll-driven morph + dock: needs animation-timeline support */
  @supports (animation-timeline: scroll()) {
    /* the animated brand owns the bar now; hide the static header mark */
    .topbar__brand {
      display: none;
    }

    /* expand the hero into a scroll runway */
    .hero {
      min-height: calc(var(--dock-end) + var(--dock-tail));
    }

    /* SVG parts transform around their own boxes, not the SVG origin */
    .brand g {
      transform-box: fill-box;
    }
    .brand__stem {
      transform-origin: center top;
    } /* collapse the I into a dot */

    /* brand becomes a fixed overlay: PHASE 1 morph in place, then PHASE 2 dock.
       rise (top) + slide (margin-top) use different props so they never fight
       the static `translate: -50% 0` that keeps it horizontally centered. */
    .brand {
      position: fixed;
      z-index: 50;
      left: 50%;
      top: calc(50vh - var(--mark-h) / 2);
      translate: -50% 0;
      animation:
        brand-rise linear both,
        brand-slide linear both;
      animation-timeline: scroll(root), scroll(root);
      animation-range:
        var(--dock-start) var(--rise-end),
        var(--shrink-end) var(--dock-end);
    }
    .brand__mark {
      animation: brand-shrink cubic-bezier(0.54, 0.29, 0.47, 0.73) both;
      animation-timeline: scroll(root);
      animation-range: var(--rise-end) var(--shrink-end);
    }
    .brand__stem,
    .brand__x {
      animation: linear both;
      animation-timeline: scroll(root);
      animation-range: 0 var(--morph-end);
      animation-timing-function: cubic-bezier(0.6, 0, 0.2, 1);
    }
    .brand__stem {
      animation-name: morph-stem;
    }
    .brand__x {
      animation-name: morph-x;
    }
    .brand__center {
      animation: morph-center linear both;
      animation-timeline: scroll(root);
      animation-range: 0 var(--morph-end);
      animation-timing-function: cubic-bezier(0.6, 0, 0.2, 1);
    }

    /* fade the arrow across the (long) dock instead of the short static range */
    .scroll-cue {
      animation-range: var(--dock-start) var(--dock-end);
    }
  }
}

/* ---------- 6. keyframes ---------- */

/* morph: L1 (full) -> L2 (merging) -> L3 (abstract), anchored on the U.
   timeline: L1 hold 0-12 | snap 12-45 | L2 hold 45-55 | snap 55-88 | L3 hold 88-100 */
@keyframes morph-stem {
  0% {
    transform: none;
  } /* full I bar (L1) */
  12% {
    transform: none;
  }
  45% {
    transform: translate(-1px, -1px) scaleY(0.3334);
  } /* dot, slid left (L2) */
  55% {
    transform: translate(-1px, -1px) scaleY(0.3334);
  }
  88% {
    transform: translate(-3px, -1px) scaleY(0.3334);
  } /* dot over U's center (L3) */
  100% {
    transform: translate(-3px, -1px) scaleY(0.3334);
  }
}
@keyframes morph-x {
  0% {
    transform: none;
  } /* X out at the right (L1) */
  12% {
    transform: none;
  }
  45% {
    transform: translate(-2px, 0);
  } /* slides in toward U (L2, exact) */
  55% {
    transform: translate(-2px, 0);
  }
  88% {
    transform: translate(-4px, 0);
  } /* left column hides inside the U -> L3, exact */
  100% {
    transform: translate(-4px, 0);
  }
}
/* counter-shift so the compacting mark stays visually centered (whole px) */
@keyframes morph-center {
  0% {
    transform: none;
  }
  12% {
    transform: none;
  }
  45% {
    transform: translateX(1px);
  }
  55% {
    transform: translateX(1px);
  }
  88% {
    transform: translateX(2px);
  }
  100% {
    transform: translateX(2px);
  }
}

/* dock: step 1 rise (top), step 2 shrink (height), step 3 slide (margin-top) */
@keyframes brand-rise {
  to {
    top: var(--bar-h);
  }
}
@keyframes brand-shrink {
  to {
    height: var(--mark-dock-h);
  }
}
@keyframes brand-slide {
  to {
    margin-top: calc(
      (var(--bar-h) + var(--mark-dock-h)) / -2 + var(--mark-bar-y)
    );
  }
}

/* scroll-cue */
@keyframes cue-bounce {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(6px);
  }
}
@keyframes cue-fade {
  0% {
    opacity: 1;
  }
  100% {
    opacity: 0;
    visibility: hidden;
  }
}