/* ============================================================
   2nth.ai — Building Blocks & Connectors design system
   Foundations mirrored verbatim from 2nth.ai / know.2nth.ai,
   extended with the node + connector component layer.
   ============================================================ */
:root {
  /* ---- brand board palette (navy / blue / sky / cream / grey) ---- */
  --ink:       #1B2A4A;
  --ink-deep:  #16223C;
  --navy:      #1B2A4A;  --navy-deep: #16223C;
  --blue:      #2F6BFF;
  --blue-glow: #5B8CFF;
  --sky:       #6EC1E4;
  --sky-muted: #A9D9EE;
  --cream:     #F5F3EF;  --grey: #E6E8EC;
  --paper:     #FFFFFF;
  --mist:      #E6E8EC;
  --slate:     #6B7689;
  --warm:      #F59E0B;  --warm-soft:   rgba(245,158,11,0.14);
  --green:     #10B981;  --green-soft:  rgba(16,185,129,0.12);
  --violet:    #8B5CF6;  --violet-soft: rgba(139,92,246,0.14);
  --rose:      #F43F5E;  --rose-soft:   rgba(244,63,94,0.12);
  --sky-soft:  rgba(110,193,228,0.18);
  --blue-soft: rgba(47,107,255,0.12);

  /* light / cream — brand default */
  --bg: var(--cream);
  --bg-raised: #FFFFFF;
  --bg-card: rgba(255,255,255,0.92);
  --bg-card-solid: #FFFFFF;
  --bg-card-hover: rgba(47,107,255,0.05);
  --grid-line: rgba(27,42,74,0.05);
  --text-primary: var(--navy);
  --text-secondary: #5B6678;
  --text-muted: #8A93A3;
  --border: rgba(27,42,74,0.10);
  --border-strong: rgba(27,42,74,0.18);
  --border-hover: rgba(47,107,255,0.28);
  --wire: rgba(91,102,120,0.45);
  --shadow: 0 6px 24px rgba(27,42,74,0.07);
  --shadow-lg: 0 24px 60px rgba(27,42,74,0.12);
  --code-bg: #16223C;

  --radius-sm: 8px; --radius-md: 12px; --radius-lg: 20px; --radius-pill: 100px;
  --maxw: 1240px;
  --gut: clamp(20px, 5vw, 64px);

  /* motion tokens */
  --t-snap: 180ms;
  --t-base: 280ms;
  --t-flow: 1400ms;
  --t-pulse: 2200ms;
  --ease-out: cubic-bezier(.22,.61,.36,1);
  --ease-snap: cubic-bezier(.5,1.4,.5,1);
}

html[data-theme="dark"] {
  --bg: var(--navy-deep);
  --bg-raised: var(--navy);
  --bg-card: rgba(27,42,74,0.66);
  --bg-card-solid: #16223C;
  --bg-card-hover: rgba(47,107,255,0.10);
  --grid-line: rgba(245,243,239,0.05);
  --text-primary: var(--cream);
  --text-secondary: rgba(245,243,239,0.72);
  --text-muted: rgba(245,243,239,0.50);
  --border: rgba(245,243,239,0.12);
  --border-strong: rgba(245,243,239,0.24);
  --border-hover: rgba(110,193,228,0.32);
  --wire: rgba(245,243,239,0.40);
  --shadow: 0 8px 30px rgba(0,0,0,0.30);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.40);
  --code-bg: #0E1626;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  font-family: 'Outfit', system-ui, -apple-system, sans-serif;
  background: var(--bg); color: var(--text-primary);
  line-height: 1.6; font-size: 17px; font-weight: 400;
  -webkit-font-smoothing: antialiased; overflow-x: hidden;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 44px 44px;
  transition: background-color .3s ease, color .3s ease;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding-left: var(--gut); padding-right: var(--gut); }
.mono { font-family: 'JetBrains Mono', monospace; }

h1, h2, h3, h4 { font-weight: 800; line-height: 1.05; letter-spacing: -2px; color: var(--text-primary); }
h1 { font-size: clamp(40px, 6.4vw, 72px); }
h2 { font-size: clamp(30px, 4.6vw, 48px); letter-spacing: -1.5px; }
h3 { font-size: 21px; font-weight: 700; letter-spacing: -0.4px; }
h4 { font-size: 16px; font-weight: 700; letter-spacing: -0.2px; }
.gradient { background: linear-gradient(135deg, var(--blue-glow), var(--sky), var(--sky-muted));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; color: transparent; }
.lead { font-size: clamp(1.02rem, 1.5vw, 1.22rem); color: var(--text-secondary); }
.sub  { font-size: clamp(0.96rem, 1.2vw, 1.06rem); color: var(--text-secondary); }

.eyebrow {
  font-family: 'JetBrains Mono', monospace; font-size: 12px; font-weight: 500;
  letter-spacing: 2px; text-transform: uppercase; color: var(--sky);
  display: inline-flex; align-items: center; gap: 8px; margin-bottom: 18px;
}
.eyebrow .num { color: var(--text-muted); }

section { padding: clamp(64px, 8vw, 104px) 0; position: relative; }
.sec-head { max-width: 760px; margin: 0 0 clamp(40px, 5vw, 56px); }
.sec-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.sec-head h2 { margin-bottom: 16px; }

/* buttons */
.btn {
  font-family: 'Outfit', sans-serif; font-size: 14px; font-weight: 600;
  padding: 12px 24px; border-radius: var(--radius-pill); border: 1px solid transparent;
  cursor: pointer; display: inline-flex; align-items: center; gap: 8px;
  transition: transform .2s var(--ease-out), box-shadow .25s ease, border-color .2s ease; white-space: nowrap;
}
.btn-primary { background: linear-gradient(135deg, var(--blue), var(--blue-glow)); color: #fff; box-shadow: 0 2px 20px rgba(37,99,235,0.22); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(37,99,235,0.32); }
.btn-ghost { background: transparent; color: var(--text-primary); border-color: var(--border-strong); }
.btn-ghost:hover { transform: translateY(-2px); border-color: var(--blue); }
.btn-mini { font-family:'JetBrains Mono',monospace; font-size:12px; letter-spacing:.04em; padding:8px 16px; }

/* nav */
header.nav { position: sticky; top: 0; z-index: 60; backdrop-filter: blur(16px);
  background: color-mix(in srgb, var(--bg) 82%, transparent); border-bottom: 1px solid var(--border); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; gap: 24px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.18rem; letter-spacing: -0.5px; flex-shrink: 0; }
.brand img { height: 30px; width: 30px; border-radius: 8px; background: #fff; padding: 2px; box-shadow: var(--shadow); }
.brand .sup { font-size: 0.6em; vertical-align: super; font-style: italic; font-weight: 700; color: var(--blue); }
/* official 2ⁿ gradient mark + wordmark */
.mark { display: inline-block; height: 1em; width: 1.15em; vertical-align: middle; flex-shrink: 0; }
.brand .mark { font-size: 1.85rem; }
.wordmark { font-weight: 800; letter-spacing: -0.5px; }
.brand .ai, .wordmark .ai { color: var(--blue); }
html[data-theme="dark"] .brand .mark { filter: brightness(0) invert(1); }
.nav-links { display: flex; align-items: center; gap: 20px; font-family: 'JetBrains Mono', monospace; font-size: 0.76rem; letter-spacing: 0.01em; }
.nav-links a { color: var(--text-secondary); transition: color .15s ease; white-space: nowrap; }
.nav-links a:hover { color: var(--text-primary); }
.nav-cta { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.icon-btn { background: none; border: 1px solid var(--border); color: var(--text-secondary); width: 38px; height: 38px; border-radius: 10px; cursor: pointer; font-size: 1rem; display: grid; place-items: center; transition: border-color .15s, color .15s; }
.icon-btn:hover { border-color: var(--border-hover); color: var(--text-primary); }
@media (max-width: 1080px) { .nav-links { display: none; } }

/* ============================================================
   BUILDING BLOCK — the core component
   ============================================================ */
.blk {
  --accent: var(--sky); --accent-soft: var(--sky-soft);
  position: relative; background: var(--bg-card-solid); border: 1px solid var(--border-strong);
  border-radius: var(--radius-md); box-shadow: var(--shadow);
  width: 230px; padding: 0; overflow: visible;
  transition: transform .25s var(--ease-out), border-color .25s, box-shadow .25s;
}
.blk::before { content:""; position:absolute; inset:0 0 auto 0; height:3px; border-radius: var(--radius-md) var(--radius-md) 0 0; background: var(--accent); }
.blk:hover { transform: translateY(-4px); border-color: var(--accent); box-shadow: var(--shadow-lg); }
.blk-head { display: flex; align-items: center; gap: 11px; padding: 15px 16px 11px; }
.blk-glyph { width: 34px; height: 34px; flex-shrink: 0; border-radius: 9px; background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent); }
.blk-glyph svg { width: 18px; height: 18px; }
.blk-titles { min-width: 0; }
.blk-name { font-weight: 700; font-size: 1.02rem; letter-spacing: -0.4px; line-height: 1.1; }
.blk-type { font-family:'JetBrains Mono',monospace; font-size: 0.62rem; letter-spacing: 1.4px; text-transform: uppercase; color: var(--accent); margin-top: 3px; }
.blk-body { padding: 0 16px 15px; }
.blk-desc { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.45; }
.blk-tags { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 11px; }
.blk-tag { font-family:'JetBrains Mono',monospace; font-size: 0.6rem; letter-spacing: .04em; color: var(--text-muted);
  border: 1px solid var(--border); border-radius: 5px; padding: 3px 7px; }

/* ports — the connection points */
.port { position: absolute; width: 13px; height: 13px; border-radius: 50%;
  background: var(--bg-card-solid); border: 2px solid var(--accent); top: 50%; transform: translate(-50%, -50%); z-index: 3; }
.port::after { content:""; position:absolute; inset: 2px; border-radius:50%; background: var(--accent); opacity:.0; transition: opacity .2s; }
.blk:hover .port::after { opacity: 1; }
.port.in  { left: 0; }
.port.out { left: 100%; }
.port.top    { top: 0; left: 50%; }
.port.bottom { top: 100%; left: 50%; }
.port.lit::after { opacity: 1; }

/* accent variants — one hue per component category */
.blk.model   { --accent: var(--sky);    --accent-soft: var(--sky-soft); }
.blk.frame   { --accent: var(--blue);   --accent-soft: var(--blue-soft); }
.blk.proto   { --accent: var(--violet); --accent-soft: var(--violet-soft); }
.blk.system  { --accent: var(--green);  --accent-soft: var(--green-soft); }
.blk.skill   { --accent: var(--warm);   --accent-soft: var(--warm-soft); }
.blk.data    { --accent: var(--sky-muted); --accent-soft: var(--sky-soft); }

/* compact variant for dense diagrams */
.blk.sm { width: 188px; }
.blk.sm .blk-head { padding: 12px 13px 9px; }
.blk.sm .blk-glyph { width: 28px; height: 28px; }
.blk.sm .blk-glyph svg { width: 15px; height: 15px; }
.blk.sm .blk-name { font-size: 0.92rem; }

/* legend chip */
.legend { display:flex; flex-wrap:wrap; gap: 9px 18px; align-items:center; font-family:'JetBrains Mono',monospace; font-size:.72rem; color:var(--text-secondary); }
.legend .lg { display:inline-flex; align-items:center; gap:7px; }
.legend .sw { width: 11px; height: 11px; border-radius: 3px; }

/* protocol chip — rides on a connector */
.proto-chip { display:inline-flex; align-items:center; gap:7px; background: var(--bg-card-solid);
  border:1px solid var(--violet); color: var(--violet); border-radius: var(--radius-pill);
  font-family:'JetBrains Mono',monospace; font-size:.68rem; font-weight:600; letter-spacing:.08em; padding: 5px 13px; box-shadow: var(--shadow); }
.proto-chip .pdot { width:6px; height:6px; border-radius:50%; background: currentColor; }

/* ============================================================
   CANVAS — where blocks + connectors compose
   ============================================================ */
.canvas { position: relative; background:
    radial-gradient(120% 120% at 50% 0%, color-mix(in srgb, var(--bg-raised) 70%, transparent), transparent 70%),
    var(--bg-raised);
  border: 1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 30px 30px; overflow: hidden; }
.canvas .wires { position:absolute; inset:0; width:100%; height:100%; pointer-events:none; z-index:1; overflow:visible; }
.canvas .nodes { position:absolute; inset:0; z-index:2; }
.canvas .node { position:absolute; transform: translate(-50%, -50%); }

/* SVG wire styling */
.wire-path { fill:none; stroke: var(--wire); stroke-width: 2; }
.wire-flow { fill:none; stroke-width: 2.5; stroke-linecap: round; }
.wire-flow.c-sky    { stroke: var(--sky); }
.wire-flow.c-blue   { stroke: var(--blue); }
.wire-flow.c-violet { stroke: var(--violet); }
.wire-flow.c-green  { stroke: var(--green); }
.wire-flow.c-warm   { stroke: var(--warm); }
.wire-dash { stroke-dasharray: 7 6; }

/* BASE = final visible state (frozen-safe). .playing only REPLAYS the build. */
.canvas .draw { stroke-dasharray: var(--len, 600); stroke-dashoffset: 0; }
.canvas.playing .draw { animation: drawWire var(--t-flow) var(--ease-out) backwards; animation-delay: var(--d, 0ms); }
@keyframes drawWire { from { stroke-dashoffset: var(--len, 600); } to { stroke-dashoffset: 0; } }

/* travelling signal particle (SMIL-driven; sits at path start when timeline idle) */
.spark { fill: #fff; r: 3.5; filter: drop-shadow(0 0 5px currentColor); opacity: 1; }

/* node pop — base visible, replays a pop while .playing */
.canvas .node { opacity: 1; transform: translate(-50%,-50%); }
.canvas.playing .node { animation: nodeIn var(--t-base) var(--ease-snap); }
@keyframes nodeIn { from { opacity: 0; transform: translate(-50%,-50%) scale(.9); } to { opacity: 1; transform: translate(-50%,-50%) scale(1); } }

@media (prefers-reduced-motion: reduce) {
  .canvas .draw { stroke-dashoffset: 0 !important; animation: none !important; }
  .canvas .node { opacity: 1 !important; transform: translate(-50%,-50%) !important; animation: none !important; }
  .spark { display: none; }
}

/* play bar */
.play-bar { display:flex; align-items:center; gap:14px; margin-top: 18px; flex-wrap: wrap; }
.play-bar .cap { font-family:'JetBrains Mono',monospace; font-size:.72rem; color: var(--text-muted); letter-spacing:.04em; }

/* ============================================================
   FOUNDATIONS — swatches / type / tokens
   ============================================================ */
.swatches { display:grid; grid-template-columns: repeat(auto-fill, minmax(140px,1fr)); gap: 12px; }
.swatch { border:1px solid var(--border); border-radius: var(--radius-md); overflow:hidden; background: var(--bg-card-solid); }
.swatch .chip { height: 76px; }
.swatch .meta { padding: 10px 12px; }
.swatch .nm { font-weight:600; font-size:.86rem; }
.swatch .hx { font-family:'JetBrains Mono',monospace; font-size:.68rem; color: var(--text-muted); margin-top:2px; }

.type-row { display:flex; align-items:baseline; gap:18px; padding:16px 0; border-bottom:1px solid var(--border); flex-wrap:wrap; }
.type-row:last-child { border-bottom:none; }
.type-row .label { font-family:'JetBrains Mono',monospace; font-size:.66rem; color:var(--text-muted); letter-spacing:1px; text-transform:uppercase; width: 120px; flex-shrink:0; }

.token-grid { display:grid; grid-template-columns: repeat(auto-fill,minmax(180px,1fr)); gap:12px; }
.token { border:1px solid var(--border); border-radius: var(--radius-md); padding:14px 16px; background: var(--bg-card-solid); }
.token .tv { font-family:'JetBrains Mono',monospace; font-size:.78rem; color: var(--sky); }
.token .tn { font-size:.78rem; color: var(--text-secondary); margin-top:4px; }

/* generic catalog grid + frame card */
.cat-grid { display:grid; gap: 20px; }
.frame { background: var(--bg-card); border:1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow); overflow:hidden; }
.frame .frame-head { display:flex; align-items:center; justify-content:space-between; gap:12px; padding:14px 18px; border-bottom:1px solid var(--border); }
.frame .frame-head .ft { font-weight:700; font-size:.96rem; letter-spacing:-.3px; }
.frame .frame-head .fk { font-family:'JetBrains Mono',monospace; font-size:.66rem; color:var(--text-muted); letter-spacing:.06em; }
.frame .frame-body { padding: 26px 22px; }
.frame .frame-note { padding: 0 18px 16px; font-size:.82rem; color: var(--text-secondary); }

/* do / dont */
.dd { display:grid; grid-template-columns:1fr 1fr; gap:18px; }
@media (max-width:760px){ .dd{ grid-template-columns:1fr; } }
.dd .item { border:1px solid var(--border); border-radius: var(--radius-md); padding:18px 20px; background: var(--bg-card-solid); }
.dd .item h4 { display:flex; align-items:center; gap:8px; margin-bottom:8px; }
.dd .item p { font-size:.88rem; color:var(--text-secondary); }
.dd .ok h4 { color: var(--green); }
.dd .no h4 { color: var(--rose); }

/* anatomy callouts */
.callout { font-family:'JetBrains Mono',monospace; font-size:.66rem; letter-spacing:.04em; color: var(--text-secondary); }

/* ---- connector demo svgs (catalog) ---- */
.conn-demo { width: 100%; height: 96px; display: block; }
.conn-demo .dpath { fill: none; stroke-width: 2.6; stroke-linecap: round; }
.conn-demo .dbase { fill: none; stroke: var(--wire); stroke-width: 2; }
.conn-demo .dport { fill: var(--bg-card-solid); stroke-width: 2.4; }
.conn-demo .spk { filter: drop-shadow(0 0 5px currentColor); }
.conn-demo .stream { stroke-dasharray: 9 7; animation: dashmove 1s linear infinite; }
@keyframes dashmove { to { stroke-dashoffset: -16; } }
.conn-chip-r { fill: var(--bg-card-solid); stroke: var(--violet); stroke-width: 1.5; }
.conn-chip-t { fill: var(--violet); font-family: 'JetBrains Mono', monospace; font-size: 13px; font-weight: 600; letter-spacing: 1px; }
@media (prefers-reduced-motion: reduce) { .conn-demo .stream { animation: none; } .conn-demo .spk { display: none; } }

/* ---- anatomy ---- */
.anatomy { position: relative; max-width: 620px; margin: 0 auto; padding: 56px 0; }
.anatomy .blk { margin: 0 auto; width: 260px; }
.anatomy .blk .port::after { opacity: 1; }
.cl { position: absolute; font-family: 'JetBrains Mono', monospace; font-size: .68rem; color: var(--text-secondary); letter-spacing: .03em; max-width: 150px; }
.cl b { color: var(--text-primary); font-weight: 600; display: block; font-size: .72rem; letter-spacing: .06em; text-transform: uppercase; margin-bottom: 2px; }
.cl::before { content: ""; position: absolute; background: var(--border-strong); }

/* footer */
footer { border-top: 1px solid var(--border); padding: 56px 0 40px; background: var(--bg); }
.foot-bottom { font-family: 'JetBrains Mono', monospace; font-size: 0.74rem; color: var(--text-muted); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }

/* reveal — base visible (never hides content); a subtle slide replays on scroll-in */
.reveal { }
.reveal.in { animation: revIn .55s var(--ease-out); }
@keyframes revIn { from { transform: translateY(16px); } to { transform: none; } }
@media (prefers-reduced-motion: reduce) { .reveal.in { animation: none; } }