/* Tuner — dark, high-contrast, phone-first, no scrolling. */

:root {
  --bg: #0e1217;
  --surface: #1a212b;
  --surface-hi: #242e3b;
  --line: #33404f;
  --text: #eef3f8;
  --text-dim: #93a4b5;
  --good: #3fd68f;
  --good-dim: rgba(63, 214, 143, 0.16);
  --warn: #f2b84b;
  --needle: #f2f6fa;
  --tap: 48px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  height: 100%;
  overflow: hidden;
  overscroll-behavior: none;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

#app {
  height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding: max(10px, env(safe-area-inset-top)) 14px max(10px, env(safe-area-inset-bottom));
  max-width: 560px;
  margin: 0 auto;
  gap: 6px;
}

/* --- instrument selector -------------------------------------------------- */

#modes {
  display: flex;
  gap: 6px;
  background: var(--surface);
  border-radius: 14px;
  padding: 5px;
}

#modes button {
  flex: 1;
  min-height: var(--tap);
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: var(--text-dim);
  font: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}

#modes button[aria-selected="true"] {
  background: var(--surface-hi);
  color: var(--text);
  box-shadow: inset 0 0 0 1px var(--line);
}

/* --- meter ---------------------------------------------------------------- */

#meter-wrap {
  position: relative;
  flex: 1 1 auto;
  min-height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#meter {
  width: 100%;
  height: 100%;
  max-height: 46vh;
  display: block;
}

#meter text {
  font-family: inherit;
  fill: var(--text-dim);
  font-size: 18px;
  font-weight: 600;
}

#needle-group {
  transform-box: view-box;
  transform-origin: 200px 232px;
  transition: transform 90ms linear;
}

#needle { stroke: var(--needle); transition: stroke 120ms; }
#pivot { fill: var(--needle); transition: fill 120ms; }

.in-tune #needle { stroke: var(--good); }
.in-tune #pivot { fill: var(--good); }
.in-tune #zone { fill: var(--good); opacity: 0.55; }
#zone { fill: var(--good); opacity: 0.18; transition: opacity 120ms; }

.idle #needle-group { opacity: 0.25; }
#needle-group { opacity: 1; transition: transform 90ms linear, opacity 300ms; }

#tune-badge {
  position: absolute;
  top: 4px;
  left: 50%;
  transform: translateX(-50%) scale(0.9);
  background: var(--good-dim);
  color: var(--good);
  border: 1px solid var(--good);
  border-radius: 999px;
  padding: 6px 16px;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.06em;
  opacity: 0;
  transition: opacity 120ms, transform 120ms;
  pointer-events: none;
}

.in-tune #tune-badge { opacity: 1; transform: translateX(-50%) scale(1); }

/* --- readout ---------------------------------------------------------------- */

#readout {
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

#note {
  font-size: clamp(64px, 19vh, 110px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  transition: color 120ms;
}

#note sub {
  font-size: 0.42em;
  font-weight: 700;
  color: var(--text-dim);
  vertical-align: baseline;
}

.in-tune #note { color: var(--good); }

#cents {
  font-size: clamp(20px, 3.4vh, 26px);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text-dim);
  min-height: 1.3em;
}

.in-tune #cents { color: var(--good); }

#freq {
  font-size: 15px;
  color: var(--text-dim);
  font-variant-numeric: tabular-nums;
  min-height: 1.3em;
}

/* --- string chips ------------------------------------------------------------ */

#strings {
  display: flex;
  gap: 8px;
  justify-content: center;
}

#strings button {
  flex: 1;
  max-width: 84px;
  min-height: 56px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  transition: background 120ms, border-color 120ms, color 120ms;
}

#strings button small {
  display: block;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-dim);
}

#strings button.active {
  border-color: var(--good);
  background: var(--good-dim);
  color: var(--good);
}

#strings button.playing {
  border-color: var(--warn);
  color: var(--warn);
  background: rgba(242, 184, 75, 0.12);
}

#hint {
  text-align: center;
  font-size: 12.5px;
  color: var(--text-dim);
  min-height: 1.2em;
}

/* --- start / permission overlay ---------------------------------------------- */

#overlay {
  position: fixed;
  inset: 0;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 22px;
  padding: 24px;
  text-align: center;
  z-index: 10;
}

#overlay.hidden { display: none; }

#overlay h1 {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

#start-btn {
  width: 168px;
  height: 168px;
  border-radius: 50%;
  border: 2px solid var(--good);
  background: var(--good-dim);
  color: var(--good);
  font: inherit;
  font-size: 19px;
  font-weight: 800;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

#start-btn:active { transform: scale(0.97); }

#start-btn svg { width: 44px; height: 44px; fill: var(--good); }

#overlay-msg {
  color: var(--text-dim);
  font-size: 15px;
  max-width: 340px;
  line-height: 1.5;
  min-height: 1.5em;
}

#overlay-msg.error { color: var(--warn); }