:root {
  --bg: #0d1117;
  --bg-elev: #161b22;
  --bg-card: #1c2230;
  --border: #30363d;
  --text: #e6edf3;
  --muted: #9da7b3;
  --accent: #58a6ff;
  --accent-2: #7ee787;
  --danger: #ff7b72;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.6;
}

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

code {
  font-family: var(--mono);
  background: rgba(110, 118, 129, 0.18);
  padding: 0.15em 0.35em;
  border-radius: 5px;
  font-size: 0.9em;
}

/* Hero */
.hero {
  background: radial-gradient(1200px 500px at 50% -10%, #1f6feb33, transparent),
              var(--bg-elev);
  border-bottom: 1px solid var(--border);
  padding-bottom: 4rem;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1000px;
  margin: 0 auto;
  padding: 1.1rem 1.5rem;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.brand { font-weight: 700; font-family: var(--mono); color: var(--accent-2); }
.nav-links { display: flex; gap: 1.1rem; flex-wrap: wrap; }
.nav-links a { color: var(--muted); }
.nav-links a:hover { color: var(--text); text-decoration: none; }

.hero-inner {
  max-width: 820px;
  margin: 2.5rem auto 0;
  padding: 0 1.5rem;
  text-align: center;
}

.hero-inner h1 {
  font-size: clamp(2.6rem, 7vw, 4rem);
  margin: 0 0 0.5rem;
  font-family: var(--mono);
  letter-spacing: -0.02em;
}

.tagline { font-size: 1.4rem; margin: 0 0 0.75rem; color: var(--text); }
.subtitle { font-size: 1.05rem; color: var(--muted); max-width: 640px; margin: 0 auto 1.75rem; }

.cta { display: flex; gap: 0.75rem; justify-content: center; flex-wrap: wrap; margin-bottom: 1.5rem; }

.btn {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  background: var(--bg-card);
  font-weight: 600;
  transition: transform 0.05s ease, border-color 0.15s ease;
}
.btn:hover { text-decoration: none; border-color: var(--accent); transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #0d1117; border-color: var(--accent); }

.badges { display: flex; gap: 0.5rem; justify-content: center; flex-wrap: wrap; }
.badges img { height: 20px; }

/* Sections */
main { max-width: 900px; margin: 0 auto; padding: 0 1.5rem; }
.section { padding: 3rem 0; border-bottom: 1px solid var(--border); }
.section h2 { font-size: 1.8rem; margin: 0 0 1rem; }
.section h3 { font-size: 1.1rem; margin: 1.5rem 0 0.5rem; }
.section p { color: var(--text); }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
}
.card h3 { margin: 0 0 0.4rem; color: var(--accent-2); font-size: 1.05rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.95rem; }

/* Code blocks */
.code-block {
  background: #010409;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  overflow-x: auto;
}
.code-block code { background: none; padding: 0; font-size: 0.88rem; color: var(--text); }

/* Demo */
.demo {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.2rem;
  margin-top: 1rem;
}
.demo-controls { margin-bottom: 0.9rem; display: flex; align-items: center; gap: 0.6rem; }
.demo-controls select {
  background: var(--bg); color: var(--text);
  border: 1px solid var(--border); border-radius: 6px; padding: 0.35rem 0.5rem;
  font-family: var(--sans);
}
.demo-io { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 700px) { .demo-io { grid-template-columns: 1fr; } }
.demo-pane label { display: block; font-size: 0.8rem; color: var(--muted); margin-bottom: 0.35rem; text-transform: uppercase; letter-spacing: 0.04em; }

#demo-input {
  width: 100%;
  min-height: 200px;
  resize: vertical;
  background: #010409;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.8rem;
  font-family: var(--mono);
  font-size: 0.9rem;
}
#demo-input:focus { outline: none; border-color: var(--accent); }

.demo-output {
  min-height: 200px;
  margin: 0;
  background: #010409;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.8rem;
  font-family: var(--mono);
  font-size: 0.85rem;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

.demo-status { font-size: 0.85rem; color: var(--muted); margin-bottom: 0.35rem; min-height: 1.2em; }
.demo-status.error { color: var(--danger); }
.demo-status.ok { color: var(--accent-2); }
.demo-note { font-size: 0.85rem; color: var(--muted); margin: 0.8rem 0 0; }

.tree-link { color: var(--accent); }
.tree-ref { color: var(--accent-2); }
.tree-id { color: #d2a8ff; }

.links-list { list-style: none; padding: 0; }
.links-list li { padding: 0.35rem 0; border-bottom: 1px dashed var(--border); }

/* Footer */
.footer {
  text-align: center;
  color: var(--muted);
  padding: 2rem 1.5rem 3rem;
  font-size: 0.9rem;
}