:root {
  --bg: #0f1115;
  --panel: #181b22;
  --panel-2: #20242d;
  --border: #2a2f3a;          /* Subtle separators (panel edges, etc.) */
  --border-strong: #6b7790;   /* Visible borders for interactive controls. */
  --border-hover: #8a96b0;    /* Hover state for the same. */
  --text: #e8eaed;
  --muted: #9aa3b2;
  --accent: #4f8cff;
  --accent-2: #6cffb0;
  --warn: #ffb86c;
  --bad: #ff6b6b;
  --good: #6cffb0;
  --shadow: 0 6px 20px rgba(0,0,0,0.35);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  min-height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.topbar h1 {
  font-size: 1.1rem;
  margin: 0;
  letter-spacing: 0.3px;
}
.topbar-title {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.topbar-repo-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-size: 0.8rem;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 999px;
  text-decoration: none;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
  white-space: nowrap;
}
.topbar-repo-link:hover,
.topbar-repo-link:focus-visible {
  color: var(--text);
  border-color: var(--border-hover);
  background: var(--panel-2);
  outline: none;
}
.topbar-repo-link svg { display: block; }
/* Hide the text on very narrow screens; the GitHub mark + tooltip still convey the link. */
@media (max-width: 560px) {
  .topbar-repo-label { display: none; }
  .topbar-repo-link { padding: 4px 8px; }
}
.topbar-actions { display: flex; gap: 8px; }

button, .file-btn {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border-strong);
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: background 0.15s, border-color 0.15s, transform 0.05s;
}
button:hover, .file-btn:hover { background: #2a3140; border-color: var(--border-hover); }
button:active { transform: translateY(1px); }
button:focus-visible, .file-btn:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.35);
}
button.primary { background: var(--accent); border-color: var(--accent); color: white; }
button.primary:hover { background: #6098ff; border-color: #6098ff; }
button.primary.active { background: var(--good); border-color: var(--good); color: #0f1115; }

main {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding: 16px;
  max-width: 1200px;
  margin: 0 auto;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  box-shadow: var(--shadow);
}

/* ----------------------------- Tuner panel ----------------------------- */

.tuner-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Open-string quick-pick (violin: G3 D4 A4 E5). */
.string-picker {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.string-picker-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
}
.string-picker-buttons {
  display: flex;
  gap: 6px;
}
.string-btn {
  /* Override generic button defaults so the picker reads as a chip group. */
  min-width: 52px;
  padding: 6px 10px;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
}
.string-btn .string-btn-sub {
  font-size: 0.7em;
  font-weight: 500;
  vertical-align: super;
  margin-left: 1px;
  color: var(--muted);
  transition: color 0.15s;
}
.string-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
  box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.25);
}
.string-btn.active .string-btn-sub { color: rgba(255, 255, 255, 0.85); }
.string-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* Small "Target: D#4 · 311.13 Hz" row, only shown when a score is loaded. */
.tuner-meta {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--muted);
}
.tuner-meta[hidden] { display: none; }
.tuner-meta-label {
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 0.7rem;
}
.tuner-meta-note {
  color: var(--accent-2);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.tuner-meta-sep { color: var(--border-strong); }
.tuner-meta-freq { font-variant-numeric: tabular-nums; }

/* Big note display + frequency / cents / status, side-by-side. */
.tuner-main {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 8px 4px;
  min-height: 88px;
}
.tuner-note-display {
  display: flex;
  align-items: baseline;
  gap: 4px;
  min-width: 130px;
  justify-content: center;
}
.tuner-letter {
  font-size: 4.2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  transition: color 0.15s, text-shadow 0.15s;
}
.tuner-octave {
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  transition: color 0.15s;
}
.tuner-details {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}
.tuner-freq {
  font-size: 1.4rem;
  font-weight: 500;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}
.tuner-cents-row {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}
.tuner-cents {
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--warn);
  font-variant-numeric: tabular-nums;
}
.tuner-status {
  font-size: 0.95rem;
  color: var(--muted);
}

/* Tuning-state colors. The note letter, cents readout and status all share
   the same class names ("in-tune" / "sharp" / "flat" / "error-high" /
   "error-low") so a single className swap on .tuner-panel re-tints everything. */
.tuner-panel.in-tune .tuner-letter,
.tuner-panel.in-tune .tuner-octave { color: var(--good); text-shadow: 0 0 18px rgba(108,255,176,0.35); }
.tuner-panel.in-tune .tuner-cents  { color: var(--good); }
.tuner-panel.in-tune .tuner-status { color: var(--good); }

.tuner-panel.sharp .tuner-letter,
.tuner-panel.sharp .tuner-octave  { color: var(--warn); }
.tuner-panel.sharp .tuner-cents   { color: var(--warn); }
.tuner-panel.sharp .tuner-status  { color: var(--warn); }

.tuner-panel.flat .tuner-letter,
.tuner-panel.flat .tuner-octave   { color: #6cb5ff; }
.tuner-panel.flat .tuner-cents    { color: #6cb5ff; }
.tuner-panel.flat .tuner-status   { color: #6cb5ff; }

/* error-high: wrong note that is *above* the target. Red signals "sharp /
   over-pitched / probably you crossed strings too far up". */
.tuner-panel.error-high .tuner-letter,
.tuner-panel.error-high .tuner-octave  { color: var(--bad); }
.tuner-panel.error-high .tuner-cents   { color: var(--bad); }
.tuner-panel.error-high .tuner-status  { color: var(--bad); }

/* error-low: wrong note that is *below* the target. A muted gray reads as
   "too low / under-pitched", complementing the red used for too-high errors. */
.tuner-panel.error-low .tuner-letter,
.tuner-panel.error-low .tuner-octave  { color: #9aa3b2; }
.tuner-panel.error-low .tuner-cents   { color: #9aa3b2; }
.tuner-panel.error-low .tuner-status  { color: #9aa3b2; }

.tuner-panel.listening .tuner-status { color: var(--muted); }

.pitch-bar-wrap {
  padding: 8px 4px 0;
}
.pitch-bar {
  position: relative;
  height: 56px;
  background: linear-gradient(90deg,
    rgba(108,181,255,0.18) 0%,
    rgba(108,181,255,0.05) 30%,
    rgba(108,255,176,0.05) 45%,
    rgba(108,255,176,0.20) 50%,
    rgba(108,255,176,0.05) 55%,
    rgba(255,184,108,0.05) 70%,
    rgba(255,184,108,0.18) 100%);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}
.pitch-bar-center {
  position: absolute;
  top: 0; bottom: 18px;
  left: 50%;
  width: 2px;
  background: var(--accent-2);
  transform: translateX(-50%);
  box-shadow: 0 0 8px var(--accent-2);
}
.pitch-bar-tolerance {
  position: absolute;
  top: 0; bottom: 18px;
  background: rgba(108,255,176,0.15);
  border-left: 1px dashed rgba(108,255,176,0.4);
  border-right: 1px dashed rgba(108,255,176,0.4);
}
.pitch-bar-needle {
  position: absolute;
  top: 4px; bottom: 22px;
  left: 50%;
  width: 4px;
  background: var(--accent);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: left 0.06s linear, background 0.1s;
  box-shadow: 0 0 10px var(--accent);
}
.pitch-bar-needle.in-tune { background: var(--good); box-shadow: 0 0 10px var(--good); }
.pitch-bar-ticks {
  position: absolute;
  bottom: 2px; left: 0; right: 0;
  display: flex;
  justify-content: space-between;
  padding: 0 4px;
  font-size: 0.7rem;
  color: var(--muted);
  pointer-events: none;
}

/* Sympathetic-resonance readout: which open string (G D A E) the played note
   is ringing, and how close to a beatless lock. The violin checking itself. */
.tuner-ring {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel-2);
  font-size: 0.85rem;
  color: var(--muted);
  transition: border-color 0.15s, background 0.15s, color 0.15s;
}
.ring-led {
  flex: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #3a4150;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.08);
  transition: background 0.12s, box-shadow 0.12s;
}
.ring-text {
  flex: 1;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.ring-meter {
  flex: none;
  width: 84px;
  height: 8px;
  border-radius: 4px;
  background: #2a3140;
  overflow: hidden;
}
.ring-meter-fill {
  height: 100%;
  width: 0%;
  background: var(--muted);
  border-radius: 4px;
  transition: width 0.08s linear, background 0.12s;
}
/* Ringing: an open string is responding. Locked: beatless — full green glow. */
.tuner-ring.ringing { color: var(--text); border-color: var(--border-strong); }
.tuner-ring.ringing .ring-led { background: var(--accent); box-shadow: 0 0 8px var(--accent); }
.tuner-ring.ringing .ring-meter-fill { background: var(--accent); }
.tuner-ring.locked {
  color: var(--good);
  border-color: var(--good);
  background: rgba(108,255,176,0.08);
}
.tuner-ring.locked .ring-led { background: var(--good); box-shadow: 0 0 12px var(--good); }
.tuner-ring.locked .ring-meter-fill { background: var(--good); }

.controls-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.control-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.control-group label {
  display: flex;
  flex-direction: column;
  font-size: 0.75rem;
  color: var(--muted);
  gap: 4px;
}
.control-group input[type="number"] {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  padding: 6px 8px;
  width: 90px;
  font-size: 0.95rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.control-group input[type="number"]:hover {
  border-color: var(--border-hover);
}
.control-group input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.35);
}
.control-group select {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  padding: 6px 8px;
  font-size: 0.95rem;
  cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.control-group select:hover { border-color: var(--border-hover); }
.control-group select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.35);
}
/* Drone toggle: lit accent while a reference drone is sounding. */
#drone-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.25);
}
/* Armed: ?drone=1 was in the URL but the browser blocks audio until the user
   interacts. Pulse to make clear a tap/keypress is needed to start it. */
#drone-btn.armed {
  border-color: var(--accent);
  color: var(--accent);
  animation: drone-armed-pulse 1.1s ease-in-out infinite;
}
@keyframes drone-armed-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(79, 140, 255, 0.0); }
  50%      { box-shadow: 0 0 0 3px rgba(79, 140, 255, 0.35); }
}
@media (prefers-reduced-motion: reduce) {
  #drone-btn.armed { animation: none; box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.35); }
}

/* Label text variants used by the floating-bar layout (see below).
   Default (narrow / multi-row): show the verbose label, hide the short one. */
.control-group .label-short { display: none; }
.control-group .label-long  { display: inline; }

/* Floating control bar: when the viewport is wide enough to fit everything
   on a single line, collapse the controls-panel into a compact horizontal
   toolbar pinned just below the topbar. */
@media (min-width: 1100px) {
  .controls-panel {
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    /* Pin below the ~60 px topbar so the bar stays visible while scrolling
       through long scores. */
    position: sticky;
    top: 62px;
    z-index: 9;
    /* "Floating" look: slightly elevated above the score panel. */
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.45);
  }
  .controls-panel .control-group {
    flex-wrap: nowrap;
    gap: 8px;
  }
  /* Subtle vertical separator between the three logical groups. */
  .controls-panel .control-group + .control-group {
    border-left: 1px solid var(--border-strong);
    padding-left: 10px;
  }
  /* Inline label text + input side-by-side. */
  .controls-panel .control-group label {
    flex-direction: row;
    align-items: center;
    gap: 5px;
    white-space: nowrap;
    font-size: 0.75rem;
  }
  .controls-panel .control-group input[type="number"] {
    width: 56px;
    padding: 4px 6px;
    font-size: 0.85rem;
  }
  .controls-panel .control-group select {
    padding: 4px 6px;
    font-size: 0.8rem;
  }
  .controls-panel button {
    padding: 5px 9px;
    font-size: 0.8rem;
  }
  /* Swap verbose -> short labels in this layout. */
  .controls-panel .label-long  { display: none; }
  .controls-panel .label-short { display: inline; }
}

.score-panel {
  min-height: 320px;
  padding: 12px;
}
#score-container {
  background: white;
  border-radius: 6px;
  padding: 8px;
  overflow-x: auto;
  min-height: 200px;
  display: none; /* hidden until a score is loaded; JS toggles to block */
  position: relative; /* anchor for the detected-pitch overlay */
}
#score-container.has-score { display: block; }

/* Long-press feedback: while the user is holding pointer-down inside the score,
   fade the page very slightly so they know the gesture is being captured. */
#score-container.long-pressing {
  cursor: progress;
  transition: filter 0.25s ease-out;
  filter: brightness(0.94);
}
#score-container {
  cursor: pointer;
  user-select: none;
  touch-action: pan-y; /* allow vertical page scroll, capture long-press for us */
}

/* Live detected-pitch indicator drawn over the score, anchored to the OSMD cursor. */
.detected-overlay {
  position: absolute;
  pointer-events: none;
  transition: top 0.06s linear, left 0.06s linear, opacity 0.15s;
  z-index: 5;
  opacity: 0;
  /* width/height set inline */
}
.detected-overlay.visible { opacity: 1; }

.detected-overlay .ghost-note {
  position: absolute;
  left: 50%;
  width: 16px;
  height: 12px;
  margin-left: -8px;
  margin-top: -6px;
  border-radius: 50%;
  background: #4f8cff;
  box-shadow: 0 0 0 2px rgba(255,255,255,0.9), 0 0 8px rgba(79,140,255,0.6);
  transition: top 0.06s linear, background 0.1s, box-shadow 0.1s;
}
.detected-overlay.in-tune .ghost-note {
  background: #2bbf6f;
  box-shadow: 0 0 0 2px rgba(255,255,255,0.9), 0 0 10px rgba(43,191,111,0.8);
}
.detected-overlay.sharp .ghost-note { background: #ff8a3d; box-shadow: 0 0 0 2px rgba(255,255,255,0.9), 0 0 8px rgba(255,138,61,0.6); }
.detected-overlay.flat  .ghost-note { background: #4f8cff; box-shadow: 0 0 0 2px rgba(255,255,255,0.9), 0 0 8px rgba(79,140,255,0.6); }
.detected-overlay.error-high .ghost-note { background: #e0524a; box-shadow: 0 0 0 2px rgba(255,255,255,0.9), 0 0 8px rgba(224,82,74,0.6); }
.detected-overlay.error-low .ghost-note { background: #9aa3b2; box-shadow: 0 0 0 2px rgba(255,255,255,0.9), 0 0 8px rgba(154,163,178,0.6); }

.detected-overlay .ghost-label {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  top: -22px;
  background: rgba(15,17,21,0.92);
  color: #fff;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
  white-space: nowrap;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  border: 1px solid rgba(255,255,255,0.15);
}
.detected-overlay.in-tune .ghost-label { background: #1f6f43; border-color: #2bbf6f; }
.detected-overlay.error-high .ghost-label { background: #7a2a25; border-color: #e0524a; }
.detected-overlay.error-low .ghost-label { background: #3a4150; border-color: #9aa3b2; }

/* A faint vertical guide between the cursor center and the ghost note,
   making the deviation visually obvious. */
.detected-overlay .ghost-guide {
  position: absolute;
  left: 50%;
  width: 2px;
  margin-left: -1px;
  background: rgba(79,140,255,0.35);
  border-radius: 1px;
}
.detected-overlay.in-tune .ghost-guide { background: rgba(43,191,111,0.35); }
.detected-overlay.sharp .ghost-guide   { background: rgba(255,138,61,0.35); }
.detected-overlay.error-high .ghost-guide { background: rgba(224,82,74,0.4); }
.detected-overlay.error-low .ghost-guide { background: rgba(154,163,178,0.4); }
.placeholder {
  text-align: center;
  padding: 60px 20px;
  color: var(--muted);
  font-size: 0.95rem;
}
.placeholder code {
  background: var(--panel-2);
  padding: 2px 6px;
  border-radius: 4px;
}

footer {
  padding: 8px 20px;
  font-size: 0.8rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  background: var(--panel);
  text-align: center;
}

/* ----------------------------- Donation panel ----------------------------- */

.donation-panel { padding: 16px 18px; }
.donation-heading {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--muted);
  margin: 0 0 6px;
  font-weight: 600;
}
.donation-blurb {
  margin: 0 0 12px;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.5;
}
.donation-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.donation-item {
  display: flex;
  align-items: center;
  gap: 10px;
}
.donation-coin {
  flex: 0 0 48px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--accent);
  text-align: center;
  padding: 4px 6px;
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  background: var(--panel-2);
}
.donation-addr {
  /* Override generic button styles: render as a flat, monospaced inline chip. */
  flex: 1 1 auto;
  text-align: left;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.82rem;
  padding: 6px 10px;
  background: var(--panel-2);
  border: 1px dashed var(--border-strong);
  color: var(--text);
  border-radius: 6px;
  overflow-wrap: anywhere;
  word-break: break-all;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.donation-addr:hover {
  background: #2a3140;
  border-color: var(--border-hover);
  border-style: solid;
}
.donation-addr.copied {
  background: rgba(108, 255, 176, 0.18);
  border-color: var(--good);
  color: var(--good);
  font-family: inherit;
  font-weight: 600;
}

@media (max-width: 720px) {
  .feedback-grid { grid-template-columns: 1fr; }
  .feedback-card .big-note { font-size: 1.8rem; }
  /* Tuner: stack big note above the details on narrow screens. */
  .tuner-main { flex-direction: column; align-items: center; gap: 8px; }
  .tuner-details { align-items: center; text-align: center; }
  .tuner-letter { font-size: 3.6rem; }
}