:root {
  --bg: #0d1117;
  --bg-elev: #161b22;
  --bg-elev2: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --text-dim: #8b949e;
  --accent: #58a6ff;
  --magenta: #bc8cff;
  --green: #3fb950;
  --red: #ff7b72;
  --yellow: #d29922;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.6;
  font-size: 16px;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, kbd, pre, samp { font-family: var(--mono); }
code { background: var(--bg-elev); padding: 2px 6px; border-radius: 4px; font-size: 0.9em; }
pre {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 16px;
  overflow-x: auto;
  font-size: 0.88em;
}
pre code { background: transparent; padding: 0; }
hr { border: none; border-top: 1px solid var(--border); margin: 48px 0; }

/* Layout */
.wrap { max-width: 980px; margin: 0 auto; padding: 0 24px; }
header.hero {
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #0d1117 0%, #131922 100%);
  padding: 80px 0 64px;
}
header.hero h1 {
  font-size: clamp(40px, 6vw, 64px);
  margin: 0 0 12px;
  letter-spacing: -0.02em;
  background: linear-gradient(90deg, #58a6ff, #bc8cff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
header.hero .tagline { font-size: 22px; color: var(--text-dim); margin: 0 0 24px; max-width: 720px; }
header.hero .badges { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 32px; }
header.hero .cta { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 12px 24px;
  border-radius: 6px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  font-size: 15px;
}
.btn:hover { background: #4493f8; text-decoration: none; }
.btn.ghost { background: transparent; border: 1px solid var(--border); color: var(--text); }
.btn.ghost:hover { background: var(--bg-elev); }

/* Nav */
nav.toc {
  position: sticky; top: 0; z-index: 10;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
  font-size: 14px;
}
nav.toc .wrap { display: flex; gap: 24px; flex-wrap: wrap; align-items: center; }
nav.toc strong { color: var(--magenta); }
nav.toc a { color: var(--text-dim); }
nav.toc a:hover { color: var(--text); text-decoration: none; }

/* Sections */
section { padding: 64px 0; border-bottom: 1px solid var(--border); }
section h2 { font-size: 32px; margin: 0 0 8px; letter-spacing: -0.01em; }
section h2 .anchor { color: var(--text-dim); margin-right: 8px; font-weight: normal; opacity: 0; transition: opacity 0.15s; }
section h2:hover .anchor { opacity: 1; }
section h3 { font-size: 22px; margin: 32px 0 8px; color: var(--text); }
section .lede { color: var(--text-dim); font-size: 18px; max-width: 720px; margin: 0 0 32px; }

/* Cards / steps */
.steps { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
}
.card h4 { margin: 0 0 8px; font-size: 16px; color: var(--magenta); font-family: var(--mono); }
.card p { margin: 0; color: var(--text-dim); font-size: 14px; }

/* Tables */
table { width: 100%; border-collapse: collapse; margin: 16px 0; }
table th, table td {
  text-align: left;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
table th { color: var(--text-dim); font-weight: 600; background: var(--bg-elev); }
table code { font-size: 13px; }

/* Live demo box */
.demo {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  margin: 24px 0;
}
.demo label { display: block; font-size: 13px; color: var(--text-dim); margin-bottom: 8px; }
.demo input[type=text] {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 12px 16px;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 16px;
}
.demo input[type=text]:focus { outline: none; border-color: var(--accent); }
.demo .preset-row { display: flex; gap: 8px; flex-wrap: wrap; margin: 12px 0; }
.demo .preset-btn {
  background: var(--bg-elev2); border: 1px solid var(--border);
  color: var(--text); padding: 4px 10px; border-radius: 4px;
  font-family: var(--mono); font-size: 12px; cursor: pointer;
}
.demo .preset-btn:hover { background: var(--border); }
.demo .output { margin-top: 16px; }
.demo .output-section { margin-bottom: 16px; }
.demo .output-section h5 { margin: 0 0 8px; font-size: 13px; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.05em; }
.trigram {
  display: inline-block;
  background: var(--bg-elev2);
  border: 1px solid var(--border);
  color: var(--green);
  font-family: var(--mono);
  font-size: 13px;
  padding: 4px 8px;
  margin: 2px;
  border-radius: 4px;
}
.trigram.literal-only { color: var(--accent); }
.trigram.dropped { color: var(--text-dim); text-decoration: line-through; opacity: 0.6; }
.note { color: var(--text-dim); font-size: 13px; font-style: italic; }

/* Animation pipeline */
.pipeline {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin: 32px 0;
  position: relative;
}
.pipeline-step {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  text-align: center;
  transition: all 0.4s ease;
  position: relative;
  min-height: 110px;
}
.pipeline-step.active {
  border-color: var(--magenta);
  box-shadow: 0 0 0 2px rgba(188, 140, 255, 0.2);
  transform: translateY(-4px);
}
.pipeline-step h5 {
  margin: 0 0 6px;
  font-size: 12px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.pipeline-step .value {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--green);
  word-break: break-all;
}
.pipeline-controls { display: flex; gap: 12px; align-items: center; justify-content: center; margin: 16px 0; }
.pipeline-controls .step-label { font-family: var(--mono); font-size: 13px; color: var(--text-dim); }

/* Mermaid container */
.mermaid {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  margin: 16px 0;
  text-align: center;
}

/* Pyramid */
.pyramid {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin: 32px 0;
}
.pyramid-tier {
  padding: 16px 24px;
  border-radius: 6px;
  text-align: center;
  font-family: var(--mono);
  font-size: 14px;
  border: 1px solid var(--border);
}
.pyramid-tier .count { color: var(--text); font-weight: 700; font-size: 18px; }
.pyramid-tier .label { color: var(--text-dim); margin-top: 4px; font-size: 12px; }
.pyramid-tier.t-e2e { width: 30%; background: rgba(255, 123, 114, 0.1); border-color: var(--red); }
.pyramid-tier.t-int { width: 55%; background: rgba(210, 153, 34, 0.1); border-color: var(--yellow); }
.pyramid-tier.t-unit { width: 85%; background: rgba(63, 185, 80, 0.1); border-color: var(--green); }

/* Footer */
footer { padding: 32px 0; color: var(--text-dim); font-size: 14px; text-align: center; }

/* Responsive */
@media (max-width: 720px) {
  .pipeline { grid-template-columns: 1fr; }
  header.hero { padding: 48px 0 32px; }
  section { padding: 40px 0; }
}