:root {
  --bg: #f4f3ef;
  --panel: #ffffff;
  --ink: #16140f;
  --ink-dim: #55524a;
  --ink-faint: #8a867a;
  --line: #d9d5c9;
  --wire: #6c7278;
  --wire-light: #a9aeb2;
  --pure: #2f7a54;
  --tempered: #c0392b;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
  --wrap: 760px;
}

* { box-sizing: border-box; }
html { background: var(--bg); }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 22px; }

.top { padding: 16px 22px; font-size: 14px; }
.top a { color: var(--ink-faint); text-decoration: none; }
.top a:hover { color: var(--tempered); }

.masthead { padding-top: 8px; padding-bottom: 12px; }
.kicker {
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--tempered);
  margin: 0 0 16px;
}
h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 54px;
  line-height: 1.08;
  margin: 0 0 18px;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.deck {
  font-family: var(--serif);
  font-size: 22px;
  line-height: 1.48;
  color: var(--ink-dim);
  margin: 0 0 6px;
  font-weight: 500;
  font-style: italic;
}

article { padding-bottom: 8px; }
p { margin: 0 0 22px; color: var(--ink); }
p.lede { font-size: 20px; }
a { color: var(--tempered); }

h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 27px;
  margin: 0 0 16px;
  color: var(--ink);
}

.langbar { margin: 18px 0 6px; font-size: 14px; color: var(--ink-faint); }
.langbar a { color: var(--ink-dim); text-decoration: none; border-bottom: 1px solid var(--line); }
.langbar a:hover { color: var(--tempered); border-color: var(--tempered); }
.langbar .current { color: var(--tempered); }

/* --- instrument panel --- */
.instrument {
  margin: 44px 0 40px;
  padding: 30px 24px 26px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  box-shadow: 0 1px 0 var(--line);
}
.instrument-caption {
  text-align: center;
  font-size: 14px;
  color: var(--ink-faint);
  margin: 0 0 22px;
}

.toggle-row {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 26px;
  flex-wrap: wrap;
}
.toggle-btn {
  font-family: var(--sans);
  font-size: 14.5px;
  font-weight: 600;
  padding: 9px 18px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink-dim);
  border-radius: 20px;
  cursor: pointer;
}
.toggle-btn.active { background: var(--ink); color: var(--panel); border-color: var(--ink); }
.toggle-btn:hover:not(.active) { border-color: var(--ink-faint); color: var(--ink); }

.string-wrap { padding: 6px 4px 2px; }
.string-wrap svg { width: 100%; height: auto; display: block; overflow: visible; }
.string-base { stroke: var(--line); stroke-width: 2; }
.string-just { stroke: var(--pure); stroke-width: 2.5; fill: none; }
.string-tempered { stroke: var(--tempered); stroke-width: 2.5; fill: none; opacity: 0.85; }
.bridge-line { stroke: var(--ink-faint); stroke-width: 1; stroke-dasharray: 3 3; }
.bridge-label { font-family: var(--mono); font-size: 11.5px; fill: var(--ink-faint); }
.pin { fill: var(--wire); }

.legend { display: flex; justify-content: center; gap: 26px; margin: 16px 0 6px; font-size: 13.5px; flex-wrap: wrap; }
.legend span { display: inline-flex; align-items: center; gap: 7px; color: var(--ink-dim); }
.legend .sw { width: 14px; height: 3px; border-radius: 2px; display: inline-block; }
.sw.just { background: var(--pure); }
.sw.tempered { background: var(--tempered); }

.play-row { display: flex; justify-content: center; margin: 22px 0 8px; }
.play-btn {
  font-family: var(--mono);
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 12px 26px;
  border: none;
  background: var(--ink);
  color: var(--panel);
  border-radius: 3px;
  cursor: pointer;
}
.play-btn:hover { background: #000; }
.play-btn:disabled { opacity: 0.55; cursor: default; }

.beat-meter { margin: 26px auto 6px; max-width: 420px; }
.beat-track {
  position: relative;
  height: 46px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 3px;
  overflow: hidden;
}
.beat-fill {
  position: absolute;
  top: 0; left: 0;
  height: 100%;
  width: 50%;
  background: var(--tempered);
  opacity: 0.75;
}
.beat-mid { position: absolute; left: 50%; top: 0; bottom: 0; width: 1px; background: var(--ink-faint); }
.beat-caption { text-align: center; font-family: var(--mono); font-size: 13px; color: var(--ink-dim); margin-top: 10px; }
.beat-caption b { color: var(--tempered); font-weight: 700; }

/* --- stat strip --- */
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  margin: 8px 0 36px;
}
.stat { background: var(--panel); padding: 20px 14px; text-align: center; }
.stat .num { font-family: var(--mono); font-size: 24px; font-weight: 600; color: var(--ink); display: block; }
.stat .lbl { font-size: 12.5px; color: var(--ink-faint); margin-top: 6px; display: block; line-height: 1.4; }

.method {
  font-size: 14.5px;
  color: var(--ink-faint);
  border-top: 1px solid var(--line);
  padding-top: 20px;
  margin-top: 8px;
}

footer.wrap { padding: 30px 22px 60px; font-size: 13.5px; color: var(--ink-faint); }
footer a { color: var(--ink-dim); }

@media (max-width: 480px) {
  h1 { font-size: 36px; }
  .deck { font-size: 19px; }
  body { font-size: 16.5px; }
  .stats { grid-template-columns: 1fr; }
  .toggle-btn { font-size: 13.5px; padding: 8px 14px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}