.tuner-intro {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .9rem;
  color: var(--muted);
  margin: 1rem 0 1.5rem;
}
.tuner-intro strong { color: var(--ink); }

.hidden { display: none !important; }

#start-screen { text-align: center; padding: 3rem 1rem 1rem; }
#start-btn {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 1rem;
  padding: .75rem 1.75rem;
  border-radius: 999px;
  background: var(--ink);
  color: var(--bg);
  border: none;
  cursor: pointer;
  transition: opacity .15s ease;
}
#start-btn:hover { opacity: .85; }
#start-screen p {
  color: var(--muted);
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .85rem;
  margin-top: 1rem;
}

#display { text-align: center; padding: 1.5rem 0 1rem; }

.note-display { margin-bottom: 1.75rem; }
#note {
  font-size: 5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1;
  font-family: ui-serif, Georgia, "Iowan Old Style", serif;
  transition: color .2s ease;
}
#freq {
  margin-top: .5rem;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .9rem;
}

.wide-meter { max-width: 28rem; margin: 0 auto 1.5rem; }
.wide-track {
  position: relative;
  height: 3rem;
}
.wide-axis {
  position: absolute;
  left: 0; right: 0;
  top: 50%;
  height: 1px;
  background: var(--rule);
  transform: translateY(-.5px);
}
.wide-targets { position: absolute; inset: 0; }
.wide-target {
  position: absolute;
  top: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  font-family: ui-sans-serif, system-ui, sans-serif;
}
.wide-target .dot {
  display: block;
  width: .5rem;
  height: .5rem;
  border-radius: 50%;
  background: var(--rule);
  margin: 0 auto;
}
.wide-target .lbl {
  display: block;
  margin-top: .35rem;
  font-size: .65rem;
  letter-spacing: .04em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.wide-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

/* Tolerance band colours — translucent so the needle reads on top */
:root {
  --tune-green: #2e7d32;
  --tune-yellow: #b58900;
  --tune-green-band: rgba(46, 125, 50, .18);
  --tune-yellow-band: rgba(181, 137, 0, .15);
}
@media (prefers-color-scheme: dark) {
  :root {
    --tune-green: #6abf69;
    --tune-yellow: #e0a82e;
    --tune-green-band: rgba(106, 191, 105, .18);
    --tune-yellow-band: rgba(224, 168, 46, .15);
  }
}

.meter { max-width: 28rem; margin: 0 auto 1.75rem; }
.meter-track {
  position: relative;
  height: 3rem;
  background:
    linear-gradient(
      to right,
      transparent 0%,
      transparent 35%,
      var(--tune-yellow-band) 35%,
      var(--tune-yellow-band) 45%,
      var(--tune-green-band) 45%,
      var(--tune-green-band) 55%,
      var(--tune-yellow-band) 55%,
      var(--tune-yellow-band) 65%,
      transparent 65%,
      transparent 100%
    ),
    var(--card);
  border: 1px solid var(--rule);
  border-radius: 4px;
}
.meter-line {
  position: absolute;
  left: 50%; top: .5rem; bottom: .5rem;
  width: 1px; background: var(--rule);
}
.needle {
  position: absolute;
  top: .25rem; bottom: .25rem;
  left: 50%;
  width: 3px;
  background: var(--accent);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: left .12s ease, background-color .2s ease;
}
.cents-labels {
  display: flex;
  justify-content: space-between;
  margin-top: .35rem;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .75rem;
  color: var(--muted);
}
#cents-text {
  font-variant-numeric: tabular-nums;
  color: var(--ink);
  font-weight: 600;
}

.strings {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: .35rem;
  max-width: 28rem;
  margin: 0 auto;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .85rem;
}
.string {
  font: inherit;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .85rem;
  text-align: center;
  padding: .65rem .25rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--card);
  color: var(--muted);
  cursor: pointer;
  transition: border-color .15s ease, color .15s ease, background .15s ease, transform .08s ease;
}
.string:hover { border-color: var(--ink); color: var(--ink); }
.string:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.string:active { transform: translateY(1px); }
.string.playing {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--bg);
}
.string.playing span { color: var(--accent); }
.string span {
  display: block;
  font-size: .65rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  margin-bottom: .15rem;
}
.string.active {
  border-color: var(--accent);
  color: var(--ink);
  background: transparent;
}
.string.active span { color: var(--accent); }

/* Three-state colouring — green (in), yellow (close), accent (off / default).
   Wide-meter dot is painted on canvas; see JS for its colour. */
#display.state-in #note { color: var(--tune-green); }
#display.state-in .needle { background: var(--tune-green); }

#display.state-close #note { color: var(--tune-yellow); }
#display.state-close .needle { background: var(--tune-yellow); }

/* state-off uses the default accent — no override needed. */

#error {
  background: var(--card);
  border: 1px solid #c0392b;
  color: #c0392b;
  padding: .9rem 1.1rem;
  border-radius: 8px;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: .9rem;
  margin: 1rem 0;
}