:root {
  --bg: #f8fafc; --panel: #ffffff; --ink: #0f172a; --muted: #64748b;
  --line: #e2e8f0; --accent: #4f46e5; --code-bg: #f1f5f9;
  color-scheme: light;
}
:root[data-theme="dark"] {
  --bg: #0b1220; --panel: #111a2e; --ink: #e2e8f0; --muted: #94a3b8;
  --line: #1e293b; --accent: #818cf8; --code-bg: #0f172a;
  color-scheme: dark;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 15px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
header {
  display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap;
  padding: 18px 24px; border-bottom: 1px solid var(--line); background: var(--panel);
}
header h1 { font-size: 17px; margin: 0; letter-spacing: -.01em; }
header p { margin: 0; color: var(--muted); font-size: 13px; flex: 1; min-width: 200px; }
header a { color: var(--accent); text-decoration: none; font-size: 13px; }
header a:hover { text-decoration: underline; }
main { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 16px; padding: 16px 24px 32px; }
@media (max-width: 860px) { main { grid-template-columns: 1fr; } }
.panel {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px; overflow: hidden;
}
.panel > h2 {
  margin: 0; padding: 10px 14px; font-size: 12px; font-weight: 600; letter-spacing: .06em;
  text-transform: uppercase; color: var(--muted); border-bottom: 1px solid var(--line);
}
.stage { height: min(62vh, 560px); }
.side { display: flex; flex-direction: column; gap: 16px; }
.body { padding: 14px; }
button {
  font: 600 13px/1 system-ui, sans-serif; padding: 8px 12px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--panel); color: var(--ink); cursor: pointer;
}
button:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
button:disabled { opacity: .45; cursor: not-allowed; }
button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.primary:hover:not(:disabled) { filter: brightness(1.08); color: #fff; }
.row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.log {
  margin: 0; padding: 12px 14px; max-height: 240px; overflow: auto;
  font: 12px/1.6 ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--muted);
  white-space: pre-wrap; word-break: break-word;
}
.log b { color: var(--ink); font-weight: 600; }
.kv { display: grid; grid-template-columns: auto 1fr; gap: 4px 10px; font-size: 13px; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
pre.snippet {
  margin: 0; padding: 12px 14px; background: var(--code-bg); border-radius: 8px;
  font-size: 12px; line-height: 1.6; overflow-x: auto;
}
input[type="range"] { width: 100%; accent-color: var(--accent); }
.legend { display: flex; gap: 10px; flex-wrap: wrap; font-size: 12px; color: var(--muted); }
.legend span { display: inline-flex; align-items: center; gap: 5px; }
.dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; border: 1px solid currentColor; }