/* ------------------------------------------------------------------ */
/* Tokens                                                             */
/* ------------------------------------------------------------------ */

:root {
  --bg:           #f6f2ea;
  --bg-2:         #efe9dc;
  --paper:        #fbf8f1;
  --ink:          #1a1815;
  --ink-2:        #3a342d;
  --muted:        #6b635a;
  --line:         #d9d1bf;
  --line-strong:  #a89e8b;

  --rail:         oklch(0.52 0.10 152);
  --rail-soft:    oklch(0.86 0.06 152);
  --clay:         oklch(0.58 0.13 38);
  --clay-soft:    oklch(0.88 0.07 38);
  --amber:        oklch(0.72 0.13 75);

  --code-bg:      #1f1c18;
  --code-bg-soft: #25221e;
  --code-ink:     #e8e2d4;
  --code-line:    #2c2924;

  --radius-sm:    4px;
  --radius:       6px;
  --radius-lg:    8px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--rail); }

.mono   { font-family: 'JetBrains Mono', ui-monospace, Menlo, monospace; }
.serif  { font-family: 'Fraunces', Georgia, serif; font-optical-sizing: auto; font-feature-settings: 'ss01'; }

.wrap   { max-width: 1180px; margin: 0 auto; padding: 0 32px; }

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

.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 32px;
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(8px);
  background: rgba(246, 242, 234, 0.85);
}
.nav-mark {
  display: flex; align-items: center; gap: 10px;
  font-family: 'JetBrains Mono', monospace;
  font-weight: 600; font-size: 15px;
}
.nav-mark svg { width: 22px; height: 22px; }
.nav-links {
  display: flex; gap: 28px;
  font-size: 14px; color: var(--muted);
}
.nav-links a:hover { color: var(--ink); }

@media (max-width: 900px) {
  .nav-links { display: none; }
}

/* ------------------------------------------------------------------ */
/* Hero                                                               */
/* ------------------------------------------------------------------ */

.hero { padding: 80px 0 60px; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 64px;
  align-items: center;
}
.eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 20px;
  display: inline-flex; align-items: center; gap: 10px;
}
.eyebrow::before {
  content: ''; width: 24px; height: 1px; background: var(--line-strong);
}
h1.display {
  font-family: 'Fraunces', Georgia, serif;
  font-weight: 400;
  font-size: clamp(48px, 6vw, 84px);
  line-height: 0.98;
  letter-spacing: -0.02em;
  margin: 0 0 24px;
  text-wrap: balance;
}
h1.display em {
  font-style: italic;
  color: var(--rail);
}
.lede {
  font-size: 20px;
  line-height: 1.5;
  color: var(--ink-2);
  max-width: 540px;
}
.hero-meta {
  display: flex; gap: 32px;
  margin-top: 40px; padding-top: 24px;
  border-top: 1px solid var(--line);
}
.hero-meta div { font-size: 13px; }
.hero-meta strong {
  display: block; font-size: 22px;
  font-family: 'Fraunces', serif; font-weight: 500;
  color: var(--ink); margin-bottom: 4px;
  letter-spacing: -0.01em;
}
.hero-meta span { color: var(--muted); }

/* ------------------------------------------------------------------ */
/* Sections                                                           */
/* ------------------------------------------------------------------ */

section {
  padding: 80px 0;
  border-top: 1px solid var(--line);
}
.sec-head {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px;
  margin-bottom: 56px;
}
.sec-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; color: var(--muted);
  letter-spacing: 0.12em;
}
.sec-title {
  font-family: 'Fraunces', serif;
  font-weight: 400;
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
  max-width: 720px;
  text-wrap: balance;
}
.sec-sub {
  font-size: 18px;
  color: var(--ink-2);
  max-width: 640px;
}

/* ------------------------------------------------------------------ */
/* Cards / stages                                                     */
/* ------------------------------------------------------------------ */

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
}
.card h3 {
  font-family: 'Fraunces', serif;
  font-weight: 500; font-size: 22px;
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}
.card p { color: var(--ink-2); margin: 0; }

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }

@media (max-width: 900px) {
  .grid-3, .grid-2 { grid-template-columns: 1fr; gap: 24px; }
  .hero-grid       { grid-template-columns: 1fr; gap: 32px; }
  .sec-head        { grid-template-columns: 1fr; gap: 16px; margin-bottom: 32px; }
  .hero            { padding: 48px 0 32px; }
  section          { padding: 56px 0; }
}

.stage {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 32px;
  position: relative;
}
.stage-label {
  position: absolute; top: 14px; left: 16px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; color: var(--muted);
  letter-spacing: 0.08em; text-transform: uppercase;
}

/* ------------------------------------------------------------------ */
/* Tabs (within a .stage)                                             */
/* ------------------------------------------------------------------ */

.tabs {
  display: flex;
  gap: 2px;
  margin: 6px 0 18px;
  border-bottom: 1px solid var(--line);
}
.tab {
  background: transparent;
  border: none;
  padding: 8px 14px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  cursor: pointer;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color 0.12s ease, border-color 0.12s ease;
}
.tab:hover { color: var(--ink); }
.tab.active {
  color: var(--ink);
  border-bottom-color: var(--rail);
}
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.tab-panel pre.code {
  max-height: 540px;
  overflow: auto;
}

/* ------------------------------------------------------------------ */
/* Buttons                                                            */
/* ------------------------------------------------------------------ */

.btn {
  background: var(--ink);
  color: var(--paper);
  border: none;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  cursor: pointer;
  letter-spacing: 0.04em;
  transition: background 0.12s ease;
}
.btn:hover  { background: var(--rail); }
.btn.active { background: var(--rail); }
.btn.ghost  {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line-strong);
}
.btn.ghost:hover { background: var(--bg-2); color: var(--ink); }

.stage-controls {
  display: flex; gap: 6px; flex-wrap: wrap;
  margin-top: 20px;
}
.hero .stage-controls {
  flex-wrap: wrap; gap: 5px;
}
.hero .stage-controls .btn {
  padding: 7px 10px; font-size: 10.5px;
  letter-spacing: 0.02em; white-space: nowrap;
}

.pill {
  display: inline-block;
  padding: 3px 10px; border-radius: 999px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; letter-spacing: 0.04em;
  border: 1px solid var(--line-strong); color: var(--muted);
}

/* ------------------------------------------------------------------ */
/* Code blocks                                                        */
/* ------------------------------------------------------------------ */

pre.code {
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 20px 24px;
  border-radius: var(--radius);
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px; line-height: 1.6;
  overflow-x: auto;
  margin: 0;
  white-space: pre;
}
pre.code .k { color: #c79658; }              /* keyword */
pre.code .s { color: #9ec98e; }              /* string */
pre.code .c { color: #6b635a; font-style: italic; } /* comment */
pre.code .n { color: #d4b96e; }              /* name (identifier) */
pre.code .p { color: #b39c7d; }              /* punctuation */
pre.code .e { color: #e08a6e; }              /* error / fail / accent */

.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: stretch; }
.compare > div { display: flex; flex-direction: column; }
.compare-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; color: var(--muted);
  letter-spacing: 0.08em; text-transform: uppercase;
  margin-bottom: 12px;
}

@media (max-width: 900px) {
  .compare { grid-template-columns: 1fr; }
}

/* ------------------------------------------------------------------ */
/* Trace log (dark)                                                   */
/* ------------------------------------------------------------------ */

.trace {
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 16px 20px;
  border-radius: var(--radius);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  line-height: 1.7;
  min-height: 140px;
  max-height: 240px;
  overflow-y: auto;
}
.trace .ln    { display: flex; gap: 12px; align-items: baseline; }
.trace .tag   { width: 24px; flex: 0 0 24px; font-weight: 600; }
.trace .tag.ok  { color: #9ec98e; }
.trace .tag.xx  { color: #e08a6e; }
.trace .tag.bb  { color: #c79658; }
.trace .name  { width: 130px; color: #d4b96e; flex: 0 0 130px; }
.trace .arrow { color: #6b635a; }
.trace .out   { color: var(--code-ink); }
.trace .out.fail { color: #e08a6e; }
.trace .dur   { color: #6b635a; margin-left: auto; }
.trace .empty { color: var(--muted); font-style: italic; }

.result {
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 16px 20px;
  border-radius: var(--radius);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  line-height: 1.7;
  min-height: 140px;
  white-space: pre-wrap;
  word-break: break-word;
}
.result .label { color: #d4b96e; }
.result .v     { color: var(--code-ink); }
.result.fail   { color: #e08a6e; }

.demo-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr 1fr;
  gap: 16px;
  margin-top: 20px;
}
@media (max-width: 900px) { .demo-grid { grid-template-columns: 1fr; } }

/* ------------------------------------------------------------------ */
/* Diagrams — Mermaid-rendered, restyled with our design tokens       */
/* ------------------------------------------------------------------ */

.diagram-host {
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 180px;
}
.diagram-host svg {
  max-width: 100%;
  height: auto;
  display: block;
  background: transparent !important;
}

/* Base node styling — paper fill, ink stroke. Mermaid sets inline
   `style`, so !important is necessary to win. */
.diagram-host svg .node rect,
.diagram-host svg .node polygon,
.diagram-host svg .node circle {
  fill: var(--paper) !important;
  stroke: var(--ink) !important;
  stroke-width: 1.5px !important;
  transition: fill 0.25s ease, stroke 0.25s ease, stroke-width 0.25s ease;
}

/* Edges — soft line by default. */
.diagram-host svg .edgePath path,
.diagram-host svg path.flowchart-link,
.diagram-host svg .flowchart-link {
  stroke: var(--line-strong) !important;
  stroke-width: 1.5px !important;
  fill: none !important;
  transition: stroke 0.25s ease, stroke-width 0.25s ease;
}

/* Labels (htmlLabels=true uses foreignObject + html spans). */
.diagram-host svg .nodeLabel,
.diagram-host svg .edgeLabel,
.diagram-host svg foreignObject div {
  font-family: 'JetBrains Mono', ui-monospace, monospace !important;
  color: var(--ink) !important;
  background: transparent !important;
}

/* Edge label background — match the paper. */
.diagram-host svg .edgeLabel rect,
.diagram-host svg .edgeLabel .label-container {
  fill: var(--paper) !important;
}

/* Hide Mermaid's default arrowheads' label box edge sometimes adds */
.diagram-host svg .edgeLabel foreignObject {
  background: var(--paper);
}

/* ------------------------------------------------------------------ */
/* Animation states                                                   */
/* ------------------------------------------------------------------ */

.diagram-host svg .node.viz-active rect,
.diagram-host svg .node.viz-active polygon,
.diagram-host svg .node.viz-active circle {
  fill: var(--rail-soft) !important;
  stroke: var(--rail) !important;
  stroke-width: 3px !important;
}

/* Glow on the active node — applied to the whole node group so the
   drop-shadow covers the rounded rect edges nicely. The pulse animates
   the glow's intensity instead of the rect's opacity, which keeps the
   label readable throughout. */
.diagram-host svg .node.viz-active {
  animation: vizGlow 1.1s ease-in-out infinite;
}

@keyframes vizGlow {
  0%, 100% {
    filter: drop-shadow(0 0 3px oklch(0.52 0.10 152 / 0.55));
  }
  50% {
    filter: drop-shadow(0 0 14px oklch(0.52 0.10 152 / 0.75));
  }
}

.diagram-host svg .node.viz-completed rect,
.diagram-host svg .node.viz-completed polygon,
.diagram-host svg .node.viz-completed circle {
  fill: var(--rail-soft) !important;
  stroke: var(--rail) !important;
  stroke-width: 2px !important;
}

.diagram-host svg .node.viz-errored rect,
.diagram-host svg .node.viz-errored polygon,
.diagram-host svg .node.viz-errored circle {
  fill: var(--clay-soft) !important;
  stroke: var(--clay) !important;
  stroke-width: 2.5px !important;
}

.diagram-host svg .node.viz-reached rect,
.diagram-host svg .node.viz-reached polygon,
.diagram-host svg .node.viz-reached circle {
  fill: var(--rail) !important;
  stroke: var(--rail) !important;
  stroke-width: 2.5px !important;
}
.diagram-host svg .node.viz-reached .nodeLabel,
.diagram-host svg .node.viz-reached foreignObject div {
  color: var(--paper) !important;
}

.diagram-host svg .node.viz-reached-fail rect,
.diagram-host svg .node.viz-reached-fail polygon,
.diagram-host svg .node.viz-reached-fail circle {
  fill: var(--clay) !important;
  stroke: var(--clay) !important;
  stroke-width: 2.5px !important;
}
.diagram-host svg .node.viz-reached-fail .nodeLabel,
.diagram-host svg .node.viz-reached-fail foreignObject div {
  color: var(--paper) !important;
}

.diagram-host svg path.viz-traversed {
  stroke: var(--rail) !important;
  stroke-width: 2.5px !important;
}
.diagram-host svg path.viz-traversed-fail {
  stroke: var(--clay) !important;
  stroke-width: 2.5px !important;
}

/* Animated token that travels along an edge */
.diagram-host svg circle.token       { fill: var(--rail); }
.diagram-host svg circle.token.fail  { fill: var(--clay); }


/* ------------------------------------------------------------------ */
/* Bullets                                                            */
/* ------------------------------------------------------------------ */

.bullet {
  padding-left: 22px; position: relative;
  color: var(--ink-2); line-height: 1.55;
}
.bullet::before {
  content: ''; position: absolute;
  left: 0; top: 9px; width: 12px; height: 1px;
  background: var(--rail);
}
.bullet b { color: var(--ink); font-weight: 600; }

/* ------------------------------------------------------------------ */
/* Phase rows                                                         */
/* ------------------------------------------------------------------ */

.phase-row {
  display: grid;
  grid-template-columns: 28px 130px 1fr;
  gap: 12px;
  align-items: baseline;
  padding: 12px 0;
  border-bottom: 1px dashed var(--line);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
}
.phase-row:last-child { border-bottom: none; }
.phase-letter { font-weight: 700; color: var(--rail); font-size: 14px; }
.phase-name   { color: var(--ink); font-weight: 600; }
.phase-ex     { color: var(--muted); }

/* ------------------------------------------------------------------ */
/* Feature grid                                                       */
/* ------------------------------------------------------------------ */

.feature {
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: var(--radius);
  padding: 28px;
}
.feature-icon {
  width: 42px; height: 42px;
  border-radius: var(--radius-sm);
  background: var(--bg-2);
  display: grid; place-items: center;
  margin-bottom: 18px;
}
.feature-icon svg { width: 22px; height: 22px; stroke: var(--ink); fill: none; stroke-width: 1.7; }
.feature h4 {
  font-family: 'Fraunces', serif; font-weight: 500;
  font-size: 20px; margin: 0 0 10px;
  letter-spacing: -0.01em;
}
.feature p {
  color: var(--ink-2);
  margin: 0;
  font-size: 15px;
}

/* ------------------------------------------------------------------ */
/* Footer                                                             */
/* ------------------------------------------------------------------ */

footer {
  padding: 56px 0 80px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
footer .row {
  display: flex; justify-content: space-between;
  align-items: end; gap: 24px;
}
footer .mono { color: var(--ink); font-weight: 600; }

@media (max-width: 720px) {
  footer .row { flex-direction: column; align-items: flex-start; }
}