*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #1a1a1a;
  --bg-card: #242424;
  --border: #333;
  --text: #e0e0e0;
  --text-muted: #888;
  --accent: #5b9bd5;
  --accent-hover: #7ab3e0;
  --accent-b: #d98f5c;
  --font: system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, monospace;
  --max-width: 860px;
}

html { font-size: 16px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

/* Nav */
header {
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
  height: 56px;
}

.site-title {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  white-space: nowrap;
}
.site-title:hover { color: var(--accent-hover); text-decoration: none; }

nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

nav ul a {
  color: var(--text-muted);
  font-size: 0.95rem;
}
nav ul a:hover, nav ul a.active { color: var(--text); text-decoration: none; }

/* Main */
main {
  flex: 1;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 3rem 2rem;
}

/* Hero */
.hero {
  text-align: center;
  padding: 2rem 0 1.5rem;
}

.hero h1 {
  font-family: var(--font-mono);
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 0.375rem;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

.hero-logo-inline {
  float: left;
  max-width: 240px;
  width: 45%;
  margin: 0 1.5rem 1rem 0;
  border-radius: 12px;
}

@media (max-width: 520px) {
  .hero-logo-inline {
    float: none;
    display: block;
    width: 100%;
    max-width: 260px;
    margin: 0 auto 1.5rem;
  }
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 2rem;
}

.flow-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.5rem 0 2rem;
}

.button {
  display: inline-block;
  padding: 0.6rem 1.4rem;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 500;
  background: var(--accent);
  color: #fff;
  transition: background 0.15s;
}
.button:hover { background: var(--accent-hover); color: #fff; text-decoration: none; }

.button-secondary {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
}
.button-secondary:hover { background: var(--border); color: var(--text); }

.intro {
  margin-top: 3rem;
  padding-top: 3rem;
  border-top: 1px solid var(--border);
}

/* Signal flow diagram */
.flow { margin-bottom: 1rem; }

.flow-meta {
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.flow-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.flow-stat {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.1rem;
  text-align: center;
}

.flow-stat-num {
  display: block;
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.flow-stat-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-top: 0.4rem;
}

.flow-layers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}

.flow-layer {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.flow-layer-a { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.flow-layer-b { border-color: color-mix(in srgb, var(--accent-b) 45%, var(--border)); }

.flow-layer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.3rem;
}

.flow-layer-title { font-size: 1.15rem; font-weight: 700; }
.flow-layer-a .flow-layer-title { color: var(--accent); }
.flow-layer-b .flow-layer-title { color: var(--accent-b); }

.flow-badge {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.3rem 0.7rem;
  border-radius: 99px;
  border: 1px solid currentColor;
}
.flow-layer-a .flow-badge { color: var(--accent); }
.flow-layer-b .flow-badge { color: var(--accent-b); }

.flow-sub {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.flow-grid { display: grid; gap: 0.5rem; }
.flow-grid-8 { grid-template-columns: repeat(4, 1fr); }
.flow-grid-4 { grid-template-columns: repeat(4, 1fr); }
.flow-grid-2 { grid-template-columns: repeat(2, 1fr); }

.flow-cell {
  height: 2.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: var(--font-mono);
  font-weight: 500;
}
.flow-layer-a .flow-cell { color: color-mix(in srgb, var(--accent) 70%, white); }
.flow-layer-b .flow-cell { color: color-mix(in srgb, var(--accent-b) 70%, white); }

.flow-pill {
  height: 2.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 99px;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.9rem;
}
.flow-layer-a .flow-pill {
  background: color-mix(in srgb, var(--accent) 18%, var(--bg));
  border: 1px solid color-mix(in srgb, var(--accent) 45%, var(--border));
  color: color-mix(in srgb, var(--accent) 75%, white);
}
.flow-layer-b .flow-pill {
  background: color-mix(in srgb, var(--accent-b) 18%, var(--bg));
  border: 1px solid color-mix(in srgb, var(--accent-b) 45%, var(--border));
  color: color-mix(in srgb, var(--accent-b) 75%, white);
}

.flow-fx {
  background: var(--bg);
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
}
.flow-fx-title { font-family: var(--font-mono); font-size: 0.85rem; font-weight: 500; }
.flow-layer-a .flow-fx-title { color: var(--accent); }
.flow-layer-b .flow-fx-title { color: var(--accent-b); }
.flow-fx-desc { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.3rem; }

.flow-master {
  height: 3.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-family: var(--font-mono);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #fff;
}
.flow-layer-a .flow-master { background: var(--accent); }
.flow-layer-b .flow-master { background: var(--accent-b); }

.flow-connector { width: 2px; height: 1.5rem; background: var(--border); margin: 0 auto; }
.flow-connector-center { height: 1.75rem; }

.flow-bus {
  max-width: 420px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: center;
  gap: 0.5rem 0.8rem;
  text-align: center;
  background: var(--bg-card);
  border: 1px dashed var(--border);
  border-radius: 99px;
  padding: 0.65rem 1.2rem;
}
.flow-bus-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text);
}
.flow-bus-desc { font-size: 0.8rem; color: var(--text-muted); }

.flow-returns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  max-width: 640px;
  margin: 0 auto;
}

.flow-return {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.9rem 1.1rem;
  text-align: center;
}
.flow-return-title { font-family: var(--font-mono); font-weight: 600; letter-spacing: 0.06em; }
.flow-return-desc { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.3rem; }

.flow-globalmaster {
  max-width: 520px;
  margin: 0 auto;
  text-align: center;
  background: var(--accent);
  border-radius: 10px;
  padding: 1.1rem 1.5rem;
}
.flow-globalmaster-title {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: 0.1em;
  font-size: 1.15rem;
  color: #fff;
  text-transform: uppercase;
}
.flow-globalmaster-desc { font-size: 0.85rem; color: rgba(255, 255, 255, 0.85); margin-top: 0.35rem; }

.flow-mainout {
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* Signal flow wiring diagram (docs page) */
.wf-wrap {
  position: relative;
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-card);
  cursor: zoom-in;
}

.wf-panel {
  width: 1720px;
  padding: 1.75rem 2rem 2rem;
  box-sizing: border-box;
  font-family: var(--font);
  color: var(--text);
  zoom: 0.46;
}

.wf-expand-btn {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.4rem 0.7rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text-muted);
  cursor: pointer;
}
.wf-expand-btn:hover { color: var(--text); border-color: var(--accent); }

.wf-wrap.wf-expanded {
  position: fixed;
  inset: 1rem;
  z-index: 1000;
  margin: 0;
  overflow: auto;
  cursor: default;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}
.wf-wrap.wf-expanded .wf-panel { zoom: 1; }

.wf-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 2rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.wf-head-title { font-size: 1.3rem; font-weight: 600; letter-spacing: -0.01em; }
.wf-head-desc { font-size: 0.85rem; color: var(--text-muted); margin-top: 0.4rem; max-width: 640px; }
.wf-head-rev {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--text-muted);
  text-align: right;
  line-height: 1.8;
  white-space: nowrap;
}

.wf-canvas { position: relative; width: 1720px; height: 1250px; }

.wf-layerlabel {
  position: absolute;
  top: 22px;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.16em;
}
.wf-layerlabel.wf-a { left: 24px; color: var(--accent); }
.wf-layerlabel.wf-b { left: 1544px; width: 152px; text-align: right; color: var(--accent-b); }

.wf-collabel {
  position: absolute;
  width: 64px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.06em;
}
.wf-collabel.wf-a { color: var(--accent); }
.wf-collabel.wf-b { color: var(--accent-b); }
.wf-collabel.wf-strong { font-weight: 600; }

.wf-box {
  position: absolute;
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-align: center;
}
.wf-box.wf-strong { font-weight: 600; }
.wf-box.wf-a { border: 1.6px solid var(--accent); color: color-mix(in srgb, var(--accent) 75%, white); }
.wf-box.wf-b { border: 1.6px solid var(--accent-b); color: color-mix(in srgb, var(--accent-b) 75%, white); }
.wf-box.wf-g { border: 1.6px solid var(--text); color: var(--text); background: var(--bg); }

.wf-box.wf-master.wf-a { background: var(--accent); border-color: var(--accent); color: #fff; }
.wf-box.wf-master.wf-b { background: var(--accent-b); border-color: var(--accent-b); color: #fff; }
.wf-box.wf-gmaster { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }

.wf-legend {
  position: absolute;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: 1.1rem 1.2rem;
  box-sizing: border-box;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
}
.wf-legend-title { font-family: var(--font-mono); font-size: 0.65rem; letter-spacing: 0.14em; color: var(--text-muted); }
.wf-legend-item { display: flex; align-items: center; gap: 0.8rem; font-size: 0.8rem; color: var(--text); }
.wf-legend-swatch { display: block; width: 2rem; height: 0; }
.wf-legend-line { border-top: 2px solid var(--text-muted); }
.wf-legend-dashed { border-top: 2px dashed var(--text-muted); }
.wf-legend-dot-wrap { display: flex; width: 2rem; justify-content: center; }
.wf-legend-xp { width: 10px; height: 10px; border: 1.6px solid var(--text-muted); border-radius: 50%; background: var(--bg-card); }
.wf-legend-junction { width: 8px; height: 8px; border-radius: 50%; background: var(--text-muted); }
.wf-legend-note { font-size: 0.75rem; color: var(--text-muted); border-top: 1px solid var(--border); padding-top: 0.7rem; }

/* Page / Article */
.page h1 { font-size: 2rem; margin-bottom: 1.5rem; }
.page h2, .intro h2 { font-size: 1.4rem; margin: 2rem 0 0.75rem; clear: left; }
.page h3, .intro h3 { font-size: 1.1rem; margin: 1.5rem 0 0.5rem; }
.page p, .intro p { margin-bottom: 1rem; }
.page ul, .page ol, .intro ul, .intro ol { margin: 0 0 1rem 1.5rem; }
.page li, .intro li { margin-bottom: 0.3rem; }

.page pre {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
}

.page code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-card);
  padding: 0.15em 0.4em;
  border-radius: 3px;
}

.page pre code { background: none; padding: 0; font-size: inherit; }

/* Section index */
.section-index {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}

.section-index li {
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 0;
  display: flex;
  align-items: baseline;
  gap: 1rem;
}

.section-index li:first-child { border-top: 1px solid var(--border); }

.section-index a { font-weight: 500; }

.section-index span {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Callouts (GitHub-style alerts) */
.markdown-alert {
  border-left: 4px solid;
  border-radius: 0 6px 6px 0;
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  background: var(--bg-card);
}

.markdown-alert p { margin-bottom: 0; }
.markdown-alert p + p { margin-top: 0.5rem; }

.markdown-alert-title {
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.35rem !important;
  text-transform: capitalize;
}

.markdown-alert-note   { border-color: #4a9eff; }
.markdown-alert-tip    { border-color: #3fb950; }
.markdown-alert-important { border-color: #a371f7; }
.markdown-alert-warning   { border-color: #d29922; }
.markdown-alert-caution   { border-color: #f85149; }

.markdown-alert-note    .markdown-alert-title { color: #4a9eff; }
.markdown-alert-tip     .markdown-alert-title { color: #3fb950; }
.markdown-alert-important .markdown-alert-title { color: #a371f7; }
.markdown-alert-warning   .markdown-alert-title { color: #d29922; }
.markdown-alert-caution   .markdown-alert-title { color: #f85149; }

/* Mailing list */
.embeddable-buttondown-form {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-top: 1rem;
}

.embeddable-buttondown-form label {
  flex-basis: 100%;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.embeddable-buttondown-form input[type="email"] {
  flex: 1 1 240px;
  padding: 0.55rem 0.85rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.95rem;
}
.embeddable-buttondown-form input[type="email"]:focus {
  outline: none;
  border-color: var(--accent);
}

.embeddable-buttondown-form input[type="submit"] {
  padding: 0.6rem 1.4rem;
  border-radius: 6px;
  border: none;
  background: var(--accent);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
}
.embeddable-buttondown-form input[type="submit"]:hover { background: var(--accent-hover); }

.embeddable-buttondown-form p {
  flex-basis: 100%;
  margin: 0;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 1.25rem 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}

footer a { color: var(--text-muted); }
footer a:hover { color: var(--text); }